ALBERT

Description: Die Toskana ist die stärkste geothermische Anomalie auf dem europäischen Kontinent. In dieser Anomalie finden sich zahlreiche lokale geothermische Felder mit hoher Enthalpie, wie z.B. das Feld von Travale. In diesem geothermischen Feld, das im Era-Graben liegt, wurden in den Jahren 1980/81 elektromagnetische Messungen durchgeführt. Es war das Ziel der Untersuchungen, die Quelle und die Ursache dieser teilweise bekannten Anomalie zu finden. Hierzu sollte die Verteilung der elektrischen Leitfähigkeit in der Erdkruste bis in Tiefen der Kruste-Mantel-Grenze mit den Methoden der Magnetotellurik und Erdmagnetischen Tiefensondierung untersucht werden. Parallel dazu wurde die geothermische Anomalie von Travale mit einer Vielzahl weiterer elektromagnetischer, seismischer und geochemischer Methoden untersucht. Das Ziel, die geothermische Anomalie in der Erdkruste zu lokalisieren, war nicht einfach zu erreichen. Deshalb war es notwendig, ein Modell der Anomalie zu erarbeiten, aus dem die Lokalität folgen sollte. Vor angegangene elektromagnetische Untersuchungen (HAAK & SCHWARZ 1981) hatten gezeigt, daß nahezu das gesamte Gebiet der Toskana als eine Anomalie der elektrischen Leitfähigkeit anzusehen ist: Gutleitende Deckschichten, mit bis zu 10 km Mächtigkeit, werden von einem hochohmigen Basement unterlagert. An einigen Meßorten deutet sich der Übergangsbereich Kruste / Mantel - in einer Tiefe zwischen 20 und 30 km - durch eine Zone hoher Leitfähigkeit an. Dieser Bereich zeichnet sich durch Lamellen hoher und extrem niedriger seismischer Wellengeschwindigkeiten aus. Petrologisch kann dieses durch eine Wechsellagerung von basischem und saurem Material gedeutet werden. Die zeitlichen Variationen des elektrischen und magnetischen Feldes wurden im geothermischen Feld von Travale in einem breiten Periodenbereich von 6 - 10.000 s registriert. Die Meßorte liegen überwiegend auf zwei Profilen, eines verläuft parallel zum Era-Graben aus der Anomalie heraus nach NW, das zweite schneidet die Anomalie senkrecht zum Graben. Der Meßpunktabstand war mit einigen hundert Metern bis zu mehreren Kilometern sehr dicht, um möglichst alle lateralen Variationen der scheinbaren spezifischen Widerstände beobachten zu können. Es zeigte sich, daß die lateralen Variationen der spezifischen Widerstände im Gebiet von Travale sehr groß waren. Bis zu Perioden von 50-100 s ist der Era-Graben die dominierende zweidimensionale Leitfähigkeitsstruktur. Die gemessenen scheinbaren spezifischen Widerstände sind bei längeren Perioden durch dreidimensionale Leitfähigkeitsstrukturen verzerrt. Die scheinbaren elektrischen Widerstände sind innerhalb der geothermischen Anomalie mit Werten bis zu 50 Qm äußerst klein, während sie nördlich des geothermischen Feldes auf 100-300 Qm ansteigen, um dann etwa 7 km NW der Anomalie wieder deutlich abzufallen. Selbst in der tieferen Kruste werden keine höheren Widerstände angetroffen. Die integrierte Leitfähigkeit weist das geothermische Feld ebenso als eine Anomalie der elektrischen Leitfähigkeit aus, während nördlich davon die "hochohmige Barriere" bestätigt wurde. Aus den Ergebnissen der Seismik und Magnetotellurik wurde ein Modell für die geothermische Anomalie von Travale und die Toskana abgeleitet, das sich in drei Stockwerke gliedert: - Das unterste Stockwerk, die Übergangszone zwischen Oberem Mantel und Unterkruste in 20-30 km Tiefe ist die Quelle auf steigender heißer Gase und Flüssigkeiten. Die Temperatur beträgt etwa 700° C. - Das mittlere Stockwerk ist von tief reichenden, vertikalen Störungen durchsetzt, die einen konvektiven Wärmetransport durch die hydrothermalen Phasen in das oberste Stockwerk erlauben. Im Gebiet von Travale hat sich durch längs- und zum Era-Graben querstreichende Störungen eine ausgeprägte Schwächezone in der Kruste gebildet, die einen besonders intensiven Wärmetransport zuläßt. Der Temperaturgradient wird mit 15° C/km angenommen. - Das oberste Stockwerk besteht aus Sedimenten und kristallinen Formationen, die im wesentlichen von horizontalen Abscherungs- und Störungsflächen durchzogen sind, in denen hydrothermale Phasen zirkulieren. Innerhalb der Basements hat sich so ein zweites Reservoir ausgebildet, welches das bekannte geothermische Reservoir in den Karbonaten in Tiefen von 1-2 km durch ein ausgeprägtes Bruchsystem speist. Die Temperatur ist in 4 km Tiefe mit 400° C sehr hoch. Die augenblicklich geförderten heißen Gase und Wässer sind meteorologischen Ursprungs und werden an der Oberkante des toskanischen Basements aufgeheizt. Aus tektonischer Sicht besteht das oberste Stockwerk aus allochthonen Decken, die während der Orogenese über die Toskana hinweggeschoben wurden. Dieser tektonischen Kompressionsphase folgte eine Phase starker lateraler Dehnungen, die bis heute andauern. Das System von Grabenbrüchen und tiefgreifenden Verwerfungen ist Ausdruck dieser Dehnungstektonik. Die damit verbundenen Störungszonen tragen zu einer Entwässerung und Entgasung der tiefen Erdkruste bei und lassen die hydrothermalen Phasen in das oberste Stockwerk aufs teigen. In ausgeprägte Schwächezonen, die die gesamte Kruste durchziehen und die durch undurchlässige Schichten nach oben abgeschlossen werden, kann sich so ein geothermisches Reservoir ausbilden.

Description: Tuscany is the strongest geothermal anomaly in continental Europe. Numerous local high enthalpy geothermal fields are to be found within this anomaly, e.g. the Travale field. Electromagnetic soundings have been carried out in this geothermal field, which lies in the Era-Graben, in the years 1980 and 1981. The aim of this study was to find the origin as well as the cause of this partly known anomaly, using the methods of magnetotelluric- and geomagnetic depth soundings to study the distribution of electrical conductivity in the earth's crust downwards to the crust/mantle boundary, at least. Parallel to this study the geothermel anomaly of Travale has been studied with the help of various other methods, including electromagnetic, seismic and geochemical surveys. To localize the geothermal anomaly in the earth's crust was not an easy task. Therefore it seemed to be necessary to develop a model of the anomaly, first, and then to localize it. Earlier electromagnetic investigations (HAAK & SCHWARZ 1981) have shown, that nearly the whole area of Tuscany corresponds to an electrical conductivity anomaly: A well conducting cover, reaching down to 10 km depth is underlain by a high resistive basement. At some places within the geothermal anomaly a zone of high conductivity has been found at the depth of the crust/mantle-boundary (between 20 and 30 km) . Seismic refraction measurements are indicating a wide transition zone between the crust und upper mantle, displayed by alternating high- und extreme low-velocity layers. The time-varying electric- and magnetic fields have been recorded in the Travale area in a broad period range from 6-10.000 s, mainly on two profiles, the one parallel, the other perpendicular to the Era-Graben. The stations have been very close to each other, spacings varied between some hundreds of meters and a few kilometers, to study lateral variations of apparent resistivities within the Graben. In deed, lateral variations of apparent resistivities have been very large in the Travale area. Up to 50-100 s the Era-Graben is the dominating 2D-structure, but for longer periods of investigation the three-dimensionality of the electrical conductivity structure has to be considered. The apparent resistivities inside the geothermal anomaly are extremely low, reaching not more than 50 Gm, even in the lower crust, whereas going up to 100-300 firn north of the geothermal field. Further to NW apparent resistivities are coming down again to 5-5o Gm. Total conductance as well indicates the geothermal field as a local conductivity anomaly, whereas more to the north the poorly conducting "barrier" has been confirmed. Based on the results of the magnetotelluic soundings and those of the seismic survey a geothermal model for the anomaly of Travale as well as for Tuscany has been developed. The crust is built up by 3 stories: - The lowermost story of the transition from the mantle to the crust at 20-30 km depth has to be regarded as the origin of hot gases and fluids. Temperature amounts to 700° C. - The central story is more or less fractured vertically so that pathways allow convective transport of heat by means of hydrothermal fluids to the upper story. In the Travale area a weak crustal zone of faults crossing over has developed, allowing the transport of heat to be very intensive. The temperature gradient is assumed to reach not more than 15° C/km. - The uppermost story consists of sediments and more or less horizontally fractured crystalline formations, filled with hot, circulating fluids. Within the basement a second reservoir has evolved, which feeds the known geothermal reservoir in the carbonate series at 1-2 km depth through fractures and cracks in the top of the basement. The temperature of about 400° C in 4 km depth is extremely high. The actually exploited hot gases and fluids are of meterological origin and heated up at the top of the basement. From the tectonic point of view, the uppermost story consists of allochthonous nappes shifted across Tuscany during orogenesis. This compressive tectonic deformation was followed by strong dilatational forces, which are still active in the whole crust, expressed by the features of graben structures and deep reaching faults. This process gives volatiles and water generated by dehydration in the deep crust the chance to rise to the uppermost story. A basement fractured at the top and an impermeable cover in the uppermost layer will then favour the development of a geothermal reservoir.

Description: thesis

Description: DFG, SUB Göttingen

Description: Die regional-geologische Aufnahme im Maßstab 1:100.000 der chilenischen Hauptkordillere zwischen 34° und 34°30' südlicher Breite ließ eine etwa 10.000 m mächtige und verschiedenartig deformierte stratigrapnisehe Abfolge erkennen, die teilweise von Intrusivkörpern durchschlagen ist.

Description: thesis

Description: DFG, SUB Göttingen

Description: Der Einsatz des LANDSAT-Satellitensystems zur Abbildung nahezu der gesamten Erdoberfläche (Maßstab 1 : 1 000 000) hat den Geowissenschaften, nicht zuletzt der Geologie, neues Datenmaterial erschlossen, das als zusätzliche Information bei der Bearbeitung großer Gebiete herangezogen werden kann. Der multispektrale Ansatz des Satellitensystems, d. h. die Abbildung der Erdoberfläche in verschiedenen Spektralbereichen vom Grün bis zum nahen Infrarot, macht neue Arbeitsmethoden zur Datenanalyse notwendig.

Description: thesis

Description: DFG, SUB Göttingen

Description: Die Insel Elba nimmt im Zusammenhang mit der alpinen und apenninen Gebirgskette eine strukturell überaus bedeutende Lage ein. So befindet sich diese größte Insel des toskanischen Archipels auf einer überleitenden Position zwischen dem nordostvergenten Nordapennin und dem westvergenten alpinen Teil Korsikas. Das Gesamtbild Elbas wird von ophiol ithischen Gesteinen mit ihrem sedimentären Auflager bestimmt. Im Ost- und Mittelteil der Insel sind weitgehend Nordapenninverhältnisse gegeben. Die Deformation der toskanischen und ligurischen Einheiten ist streng ostvergent, wobei in den eugeosynkl in〈* len Liguriden, welche klar mit der Bracco-Einheit korreliert werden können, Erscheinungen einer Thermodynamometamorphose fehlen. Dagegen werden auf West-Elba in den Ophiol ithserien enorme Abweichungen schon im Aufschlußbild deutlich, da diese intensiv isoklinal verfaltet und kräftig geschiefert sind.

Description: Elba, the greatest Island of the Tuscan Archipelago» has an important position within the Alpine and Apenninie chains: It is situated in the transitional zone between the NE-vergent Northern Apennines and the Alpine part of Corsica with Western vergencies. Elba shows a widespread distribution of ophiolitic rocks and their sedimentary cover. In Eastern and Middle Elba there are conditions which are largely similar to those of the Northern Apennines. The tectonic trend of the Tuscan and Ligurian units is clearly eastward. The eugeosyncl inal Ligurides, which can be correllated with the Bracco unit of the Apennines, are not affected by thermodynamometamorphism. In this respect this area differs from the Western part of Elba, where also ophiolitiferous series occur. These however show tight isoclinal folding and strong cleavage.

Description: thesis

Description: DFG, SUB Göttingen

Description: Seit gut 20 Jahren wird die Grundwassernutzung im Rahmen des "New Valley Project" stark vorangetri eben . Um eine langfristige Funktionsfähigkeit der Entwicklungsprojekte zu gewährleisten, mußte die Frage der Grundwasserbildung und -herkunft geklärt werden. Radiokarbon-Altersbestimmungen, Isotopenuntersuchungen und hydrochemische Analysen zeigen, daß das Grundwasser des Dakhl a-Beckens fossil ist; eine rezente Grundwasserneubildung ist nicht nachzuweisen. Grundwasserbildung fand letztmals während des letzten Hauptpluvials (〉20.000 Jahre B.P. ) statt, postpluviale Grundwässer wurden nicht nachgewiesen. Das Grundwasser wurde aus Niederschlägen atlantischer Feuchtmassen gebildet, die über eine Westwinddrift in die östliche Sahara gelangten. Die Grundwasserbildung war weitgehend lokal, großräumige Grundwasserbewegung findet nicht statt. Die Möglichkeit von Überläufen fossiler Grundwässer aus Nachbarbecken, wie Nordsudan-Becken und Kufra -Becken , konnte nicht geklärt werden. Aufgrund der analytischen Untersuchungen ist der Aquifer des Dakhl a-Beckens weder regional noch vertikal gliederbar; seine Ausbildung ist bei großräumiger Betrachtung sehr homogen. Wegen der ungleichen Verteilung der Informationen im Dakhla-Becken wurde zur Grundwassermassenberechnung ein dreidimensionales Computermodell entwickelt, das über Regressionen mit Polynomen höherer Ordnung die Volumina des Aquifers errechnete. Soweit überprüfbar, erbrachte das Modell gute Ergebnisse, so daß es künftig auch in Becken angewandt werden kann, von denen noch weniger Informationen vorliegen. Es wurde ein Zeit-Volumen-Modell erstellt, das zum einen den Absenkungsverlauf des Grundwasserspiegels beschreibt, zum anderen die zur Klärung der Grundwassersituation verwendeten Parameter stützt und sie als weitgehend richtig ausweist.

Description: For about twenty years the use of the groundwater has been increased closely within the frame of the "New Valley Project". The questions of the formation and origin of the groundwater had to be elucidated in order to insure the long time function of the project. The investigations of isotopes, radiocarbon age dating and the hydrochemical analyses indicate the groundwater of the Dakhla Basin to be fossil; a recent formation of groundwater may safely be excluded. The last time groundwater formation occurred was during the last main pluvial (〉20,000 B.P.); there are no indications of postpluvial formation. The groundwater was formed by the precipitation of Atlantic humid air masses which reached the eastern Sahara by western drift. The groundwater formation was mainly local, regional groundwater movement does not occur. The possible overfl ow of fossil groundwater from the neighbouring basins as the North Sudan Basin and the Kufra Basin could not be clarified. Analytical investigations show the aquifer of the Dakhla Basin neither regionally nor vertically divisible; the shape is very nomogeneous over large regions. Since informations about the Dakhla Basin are distributed unevenly for the calculation of the groundwater masses the volumes of the aquifer were calculated using a three dimensional Computer model working with polynomal regressions of higher order. As far as possible the model shows good results; therefore it can be used in the future in basins with even less informations. A model of time and volume was made describing the decrease of the waterhead; the same model supports the Parameters used for the analysis of the groundwater Situation indicating that the Parameters are correct.

Description: thesis

Description: DFG, SUB Göttingen

Description: Mit der Abu Bal las Formation sind erstmals unterkretazische marine Ablagerungen innerhalb der Kubischen Gruppe Südwest-Ägyptens nachgewiesen worden. Transgression und Regression erfolgten wahrscheinlich während des Apt. Die Ablagerungen der Formation treten in der Region zwischen dem Gilf Kebir und dem Abu Tartur Plateau zutage, wo sie die fluviatilen Sandsteine der Six Hills Formation (Basal Clastics) im Liegenden von den ebenfalls fluviatilen Sandsteinen der Sabaya Formation (Desert Rose Beds) im Hangenden trennen. Die Abu Bal las Formation besteht lithologisch überwiegend aus roten und grünen Tonsteinen, untergeordnet kommen auch Silt- und Feinsandsteine vor. Die Mächtigkeit beträgt durchschnittlich 20 bis 30 m, örtlich kann sie 45 m erreichen. Nach Westen, Süden und Osten keilt die Formation aus. Die Ablagerungen der Formation lieferten neben etlichen Pflanzenresten eine unerwartet arten- und individuenreiche marine Fauna. Im einzelnen wurden gefunden: Pflanzen: Vier bisher unbekannte Fruktifikationen sowie acht weitere bisher zum Teil unbekannte Pflanzenreste. Foraminiferida: Drei agglutinierende Arten. Scleraciinia: Eine ahermatype Art. Brachiopoda: Eine inarticulate Art. Scaphopoda: Eine Art. Gastropoda: Acht Arten. Bivalvia: 33 Arten. Die Bivalven stellen die umfangreichste Fossilgruppe innerhalb der Fauna dar. Annelida: Eine Art. Arthropoda: Zwölf Arten. Echinoidea: Eine Art. Vertebrata: 14 Arten. Spurenfossilien: 23 Arten. Koprolithen: Vier Formen. Folgende zwei Taxa sind neu aufgestellt worden: Palaeosabellaxda aegyptiaca gen. nov., sp. nov.; Anomoeodus parvulus sp. Nov.. Die Abu Ballas Formation ist in einem sehr flachen Epikontinentalmeer abgelagert worden. Die Wassertiefe betrug in dem Gebiet, in dem die Formation zutage tritt, höchstens etwa 20 m, größtenteils war sie wahrscheinlich bedeutend geringer. Die Salinität des Meereswassers war fast während der gesamten Zeit vermindert, in Küstennähe kam es aber zu starken Schwankungen und kurzfristig auch zu euhalinen Verhältnissen. Es lassen sich mehrere Faziesräume des oberen und mittleren Sublittorals unterscheiden, die durch unterschiedliche Sedimente und durch verschiedene Faunengemeinschaften gekennzeichnet sind. Im Übergangsbereich zwischen mariner und fluviatiler Sedimentation kam es Örtlich zu Deltaschüttungen und zur Ausbildung einer Marsch. Die Apt-Transgression überflutete weite Teile Ägyptens. Lediglich der äußerste Südwesten und der Südosten des Landes sowie große Teile der Eastern Desert und der südliche Sinai blieben Festland.

Description: The Abu Ballas Formation is the first known Lower Cretaceous marine transgression within the Nubia Group of southwestern Egypt. Transgression and Regression probably happened at Aptian times. The depositions of the formation crop out in the area between the Gilf Kebir and the Abu Tartur Plateau. They are underlain by fluvial deposits of the Six Hills Formation (Basal Clastics) and overlain by fluvial deposits of the Sabaya Formation (Desert Rose Beds). Lithologically the Abu Ballas Formation mainly consists of red and green claystones, siltstones and finegrained sandstones are more rarely. The thickness averages 20 to 30 ms, reaching 45 ms locally. To the west, south, and east the formation wedges out. Aside from several plant remains the formation yields a marine fauna, which is unexpectedly rieh in species and individuals. There were found the following flora and fauna: Plants: Four fructifications unknown till now and eight other partly unknown plant remains. Foraminiferida: Three agglutinated species. Scleractinia: One ahermatypic coral . Brachiopoda: One inarticulate species. Scaphopoda: One species. Gastropoda: Eight species. Bivalvia: 33 species. The Bivalvia represent the most extensive group within the fauna. Annelida: One species. Arthropoda: Twelve species. Echinoidea: One species. Vertebrata: 14 species. Trace fossil s; 23 species. Coprolites: Four forms. The following two new taxa have been established: Palaeosabellaria aegyptiaea gen. nov., sp. nov. (Annelida: Hermell idae) and Anomoeodus parvulus sp. nov. (Hol ostei: Pycnodontidae) .The Abu Ballas Formation has been deposited in a very shallow epi Continental sea. In the area, where the formation crops out, the depth of the water was probably ca. 20 ms at most, usually it was considerably shallower. The salinity was reduced to some degree, near the coast however, it varied in a high extent. For a short time the conditions were euhaline. Several facies of the upper and middle sublittoral can be distinguished, characterised by different Sediments and different faunal associations. In the transitional zone between the marine and the fluviatile facies deltaic and marsh deposits were found locally. This transgression had flooded large areas of Egypt. Only the extreme southwestern part and the southeastern part of the country, probably wide areas of the Eastern Desert too, and the Southern half of the Sinai remained Continental.

Description: thesis

Description: DFG, SUB Göttingen

Description: Aus feinstratigraphisch aufgenommenen Profilen im kontinentalen Neogen (Jungpliozän-Altpleistozän) der Insel Kos (Dodekanes) werden horizontiert gesammelte Populationen der limnischen Gastropoden-Gattung Viviparus biometrisch untersucht und aufgrund dessen die bestehende taxonomische Aufteilung revidiert. Die Höhe und Breite der allometrischen Gehäuse werden an jeder Windung ermittelt und dargestellt. Diese Daten werden auf signifikante Unterschiede zwischen Populationen geprüft und die verallgemeinerten Trennwerte nach der Häufigkeit aufgetragen. Sie sind meist nahezu normal verteilt. Daraus wird auf ähnliche Variabilität der Populationen geschlossen. Durch die Cluster-Analyse wird die Ähnlichkeit der Individuen jeder Probe hierarchisch geordnet und gezeichnet (Dendrogramme) . Vermuteter Sexual-Dimorphismus der Gehäuse ist wahrscheinlich, kann aber nicht mit Sicherheit bestätigt werden. Im Laufe der Zeit verändern sich glattschalige kontinuierlich zu drei gekielten Formen trotz mehrfachen und deutlichen Milieuwechsels. Damit ist genetisch bedingte evolutive Umgestaltung der Gehäuse wahrscheinlich zu machen. Die Einordnung der Individuen aller Populationen in verschiedene Formklassen verdeutlicht diesen evolutiven Trend. Gleichzeitig treten fünf distinkte Häufigkeitsmaxima übereinander auf. Dadurch ist eine gegenüber anderen Methoden erheblich verfeinerte biostratigraphische Gliederung der ca. 250 m mächtigen nv:- parus- führenden Neogenfolge von Ost-Kos möglich.

Description: On Kos Island, populations of the limnic gastropod genus Viviparus taken from defined horizons from Neogene (Late Pliocene to Early Pleistocene) sequences have been analyzed biometrically and have been revised paleontologically. Height and width of all coils of the allometric Shells have been measured and plotted. These data are examined with respect to significant differences between the populations. The discriminant scores of the samples show approximately Gaussian distributions. From this, a similar variability of the populations is deduced. The similarity of individuals within populations is hierarchically clustered in dendrograms. A supposed sexual dimorphism of the analyzed Shells is probable but has not been confirmed. In spite of several remarkable environmental changes, strongly sculptured forms conti nually develop from smooth Shells in the course of approximately 2 m.y. This proves a genetically controlled development of the various forms, i.e. evolution. By the arrangement of all the individuals in different morphological classes this evolutionary trend is illustrated. Moreover, five distinct maxima of frequency distributions are found. Accordingly, a refined biostratigraphic subdivision of the Neogene sequence bearing Viviparus in eastern Kos (approx. 250 m thick) has been rendered possible.

Description: A l'Est de l’Tle de Kos (Dodecanese, Grece), des populations d’horizons determines du genre de gasteropodes limniques de Viviparus, provenant d’une sequence ininterrompue du Neogene Continental (Pliocene superieur au Pleistocene inferieur) ont ete etudiees par des methodes statistiques multivariees. Grace ä leurs resultats, une revision du groupement taxonomique existant est effectuee. La hauteur et la largueur de chaque circonvolution des coquilles allometriques sont mesurees et presentees graphiquement. Ces dates morphometriques sont examinees quant aux differences significatives dont leurs distances general isees sont tracees en distributions de frequence. Celles-ci sont pour la plupart normalement distribuees. De lä est deduite une variabilite ressemblante des populations. La ressemblance des individus de chaque faune est evaluee par l'analyse des similarites et tracees hierarchiquement en forme de dendrogrammes . II en res ulte la vraisemblance d'un dimorphisme sexuel de ces coquilles du genre Viviparus. Au cours de 2 millions d'annees environ, des formes lisses se sont developpees conti nuellement en forme multicarenees malgre plusieurs changements ecologiques prononces. Ainsi, le developpement de la forme de coquilles, genetiquement controllee, donc son evolution, peut etre constate. Le classement des individus de chaque population en dix types morphologiques differents precise cette tendance evolutive. En plus, cinq maxima de distributions de frequence sont nettement ä distinguer. De ce fait resulte, en comparaison avec d'autres methodes appliquees jusqu'ä present, une subdivision biostratigraphique plus detaillee de la sequence neogene de 1'Tie de Kos, epaisse de 250 m environ.

Description: thesis

Description: DFG, SUB Göttingen

Description: Unter der Bezeichnung "Scaglia" wird im Südalpin und im Nordapennin eine Folge überwiegend pelagischer, kreide- und tertiärzeitlicher Sedimente zusammengefaßt, die aus bunten Tonschiefern, Mergeln und Kalken besteht. Zusätzlich können detritische Kalke, Breccien und Konglomerate auf treten. Die in der vorliegenden Arbeit behandelten Scaglia-Sedimente der Toskanischen Decke ("Scaglia Toscana“) konnten nach ihrer Lithofazies sechs Formationen zugeordnet werden. Mit Hilfe mikropaläontologischer Untersuchungen an pelagischen Foraminiferen wurden die Ablagerungen biostrati graphisch datiert; sie repräsentieren den Zeitraum Alb – Oligozän. Zahlreiche im Gelände auf genommene Schichtfolgen wurden lithofaziell und biostrati graphisch bearbeitet. Die Profile wurden korreliert und in einem standardisierten Normal profil zusammengefaßt. Es zeigte sich, daß die Verbreitung der Fazies typen sowie ihre Mächtigkeit von einer Beckenkonfi guration abhängt, die bereits seit dem Lias erkennbar ist. Eine generelle Umgestaltung des Ablagerungsraumes an der Wende Unter-/Oberkreide, wie sie als Folge der paläoapenninen Phase von verschiedenen Autoren angenommen wurde, konnte nicht nachgewiesen werden. Aus der Abfolge der mesozoischen bis alttertiären Ablagerungen läßt sich vielmehr im Zentrum des Sedimentationsraumes ein Hochgebiet mit lückenhafter und geringmächtiger Sedimentation rekonstruieren, welches vom älteren Jura bis in das Eozän hinein Bestand hatte und beiderseits von Becken mit mächtigeren und vollständigeren Schichtfolgen gesäumt wurde. Diese Schwellenregion wird als "Zentral toskanisches Hochgebiet" bezeichnet und entspricht teilweise der von BOCCALETTI & BORTOLOTTI (1965) rekonstruierten "Dorsale costiera". Im Oligozän - ?Miozän wurden diese morphologischen Strukturen entland der Linie Livorno-Sillaro in zwei gegeneinander versetzte Blöcke zerlegt. Die paläoapennine Phase (Wende Unter-/Oberkreide) sowie auch die ligurische Phase (Eozän), die in den internen Bereichen des Nordapennins (Ligurikum) zu einer bedeutenden Umgestaltung der Sedimentationsraume führten, dokumentieren sich in der Schichtfolge der Toskanischen Decke lediglich im vermehrten Auftreten von Breccien, Konglomeraten und ersten ganz lokal vorkommenden Grauwackenschüttungen. Im Neokom und verstärkt mit Beginn der Scaglia-Sedimentation im Alb und damit auch zeitgleich mit der palaoapenninen Phase, setzt im toskanischen Abi agerungs raum außerdem von NE her die Schüttung detritischer Kalke ein. Diese füllen zunächst das Becken östlich des Zentral toskanischen Hochgebietes ; vom Eozän ab greifen sie auch auf die westlichen Gebiete über. Diese detritischen Kalke der Scaglia Toscana zeigen Sedimentstrukturen wie sie für Turbiditablagerungen typisch sind. Sie müssen als Kalkflysch angesprechen werden, der sich mit normal sedimentierten Ablagerungen verzahnt. Die Scaglia Toscana kann deshalb nicht mehr als rein pelagische Schichtfolge der Präflyschphase angesehen werden, sondern repräsentiert, wenigstens in Teilen, schon das volle Flyschstadium des Drögens.

Description: In the Southern Alps and in the Northern Apennines the name "Scaglia" is used for a mainly pelagic, cretaceous to tertiary sedimentary sequence which is composed of variegated clayey shales, marls and limestones. In this succession detrital limestones, breccias and conglomerates may occur as well. The Scaglia Sediments of the Tuscan Nappe ("Scaglia Toscana") examinated in the present study were subordinated to six forma tions according to their lithofacies. The Sediments were dated biostratigraphically by means of micropaleontological studies on pelagic foraminiers; they represent the period between Albian and Oligocene. Detailed field investigations and biostratigraphical datings of numerous strati graphical sequences allowed a correlation of serial sec tions and a summari za tion to a Standard! zed columnar section. It was evident that the distribution of the different facies types as well as their thickness depends on a bas in topography which is recognizable since Liassic times. A general transformation of the deposition area at the boundary of Lower and Upper Cretaceous as a consequence of the "Paleoapenninic Phase", postulated by several authors, could not be proved. From the sequence of the Mesozoic to Paleogene sediments one could rather reconstruct a ridge characterized by thin Sedimentation and Stratigraphie gaps in the centre of the deposition area. This rise existed from the Juras sic up to the Eocene and was accompanied on both sides by bas ins with thicker and more complete strati graphical sequences. This ridge is called "Central Tuscan Ridge" ("Zentral toskanisches Hochgebiet") and corresponds partly to the "Dorsale costiera" reconstructed by BOCCALETTI & BORTOLOTTI (1965). In the Oligocene - (?)Miocene these morphological structures were divided into two blocks which were displaced versus each other along the Livorno-Sillaro-Structure. The "Paleoapenninic Phase" (Lower/Upper Cretaceous) as well as the "Ligurian Phase" (Eocene) which initiated significant translocations in the inner areas of the Northern Apennines (Ligurids), are documented within the sequence of the Tuscan Nappe only by an increasing occurrence of breccias, conglomerates and a first local accumulation of graywackes. In the Neocomian and even more intensive with the beginn! ng of Scaglia-sedimentation and therefore contemporaneous with the "Paleoapenninic Phase", in the Tuscan area the accretion of detrital limestones begins from NE. At first these limestones fill up the bas in east of the Central Tuscan Ridge and from the Eocene on they also start spreading out towards Western areas. These detrital Times tones of the Scaglia Toscana show sedimentary fabrics typical of turbidites. They represent a carbonate facies which interfingers with normal sedimentated depositions. Thus the Scaglia Toscana can no longer considered a pure pelagic sequence of the pre-flysch period but represents, at least in parts, the flysch stage of the orogene.

Description: Nel Sudalpino e nel Appennino settentrionale con il nome di "Scaglia" viene intesa una sequenza di sedimenti per lo piü pelagici, di etä Cretaceo-Terziaria, ehe e costituita da scisti argillosi policromi, marne e calcari; possono essere presenti anche calcari detritici, brecce e conglomerati. I sedimenti della Scaglia della Falda Toscana (Scaglia Toscana) trattati nel presente lavoro, potrebbero venire attribuiti, in base al la loro litofacies, a sei formazioni. Con l'aiuto di ricerche micropaleontologiche su foraminiferi pelagici le fasi di sedimentazione sono state datate in un periodo tra l'Albiano e l’Oligocene. Numerose sequenze di strati osservate in campagna sono state esaminate sia dal punto di vista della litofacies ehe da quello biostratigrafico. Le sezioni strati graf i ehe sono state correlate e vengono rappresentate da una sezione Standard. Si e notato ehe la diffusione dei tipi di facies come pure il loro spessore sia dipeso dal la presenza di un bacino esistente giä dal Lias. Contrariamente a quanto e stato affermato da vari autori , non si e potuto di mostrare un cambiamento dei bacini di sedimentazione nel periodo tra il Cretaceo inferiore e quello superiore, come conseguenza della fase paleoappeninica. Dalle sequenze sedimentarie dal Mesozoico al Paleogene si lascia ricostruire nel centro del bacino di sedimentazione una regione elevata con sedimentazione incompleta e scarsa, ehe e esistita dal Giurassico inferiore fino all'Eocene ed era circondata dall'una e dall’altra parte da bacini con sequenze sedimentarie complete e di grande spessore. Questa regione montuosa e ondulata e indicata con il nome di "Dorsale Toscana centrale” ( "Zentral toskanisches Hochgebiet") e corrisponde in parte al la "Dorsale costiera" ricostruita da BOCCALETTI & BORTOLOTTI (1965). Nell ‘Oligocene - (?)Miocene queste strutture morfologiche sono state divise in due blocchi rivolti l’uno contro l'altro. La fase paleoappeninica (tra Cretaceo inf. e sup.) e la fase ligure (Eocene), ehe nelle zone interne del Nord Appenino (Ligurico) hanno portato ad un notevole cambiamento dei bacini di sedimentazione, sono documentate nel la sequenza sedimentaria della Falda Toscana tramite la presenza di brecce, conglomerati e le prime deposizioni di grovacke. Nel Neocomiano e ancor piü con 1‘inizio della sedimentazione della Scaglia nell ’Albiano, contemporaneamente alla fase paleoappeninica, comincia nel bacino toscano la sedimentazione di calcari detritici da NE. Questi riempiono dapprima il bacino posto al lato orientale della "Dorsale Toscana centrale"; dall'Eocene in poi si diffondono anche nella zona occidentale. Questi calcari detritici della Scaglia Toscana mostrano strutture sedimentarie tipiche delle turbiditi. Essi devono venire considerati flysch cal carei i quali si intercalano alla sedimentazione normale. Per questo motivo la Scaglia Toscana non puo piü essere considerata una pura sequenza pelagica della fase preorogenica ma rappresenta, almeno in parte, giä il pieno stadio del flysch, durante l'orogenesi.

Description: thesis

Description: DFG, SUB Göttingen

Description: Die Untersuchungen der Grundwasserbeschaffenheit und der hydrogeologischen Zusammenhänge erstrecken sich auf das nördliche Stadtgebiet von Berlin (West), das ein Teil des Einzugsgebietes der oberen Havel ist. Das betrachtete Grundwassersystem erfaßt die im Hangenden des mittel oligozänen Septarientons in normaler stratigraphischer Abfolge ausgebildeten Ablagerungen des Oberoligozäns, Miozäns und Pleistozäns Die Mächtigkeiten der auftretenden Schichtfolgen sind abhängig von einer durch Salzbewegungen verursachten Aufwölbung im NE und einer im W gelegenen Salz-Emigrationszone. Folglich treten die größten Mächtigkeiten (ca. 380 m) im W des Untersuchungsgebietes auf. Die pleistozänen Ablagerungen erreichen ihre größten Mächtigkeiten im Bereich einer Erosionsrinne, die im mittleren Teil des Untersuchungsgebietes bis in den Septarienton eingeschnitten ist. Die Betrachtung der Druck- und Fließverhältnisse zeigt sowohl für das tiefere, gespannte Grundwasser der tertiären Schichtfolgen als auch für den oberen Grundwasserleiter einen hauptsächlich nach SW gerichteten Grundwasserabstrom. Für die Potentialdifferenzen zwischen dem oberen und dem gespannten Grundwasser kann in den Bereichen großer Grundwasserentnahmen ein relatives Ansteigen der Druckfläche des tieferen Grundwassers erkannt werden. Die höhere Druckfläche des tieferen Grundwassers weist, in Abhängigkeit von der Durchlässigkeit der stauenden Schichten, auf ein Aufsteigen tieferer Grundwässer hin. Dies wird bekräftigt durch die Ergebnisse der geothermischen Untersuchungen, die für die entsprechenden Bereiche eine großflächige positive geothermische Anomalie erkennen lassen. Der Chemismus der untersuchten Grundwässer läßt im allgemeinen mit zunehmender Tiefe eine Abnahme der Gesamtmineralisation erkennen. Die durchschnittliche Gesamtmineralisation der tieferen Grundwässer liegt mit 15.07 mval/1 unter der des Grundwassers der pleistozänen Schichten (17.38 mval/1). Die räumliehe Betrachtung der Mineralisationsverteilung läßt für die tieferen Grundwässer im NE- und SE-Teil des Untersuchungsgebietes eine erhöhte Mineralisation erkennen, die hauptsächlich auf höhere Kalziumsulfatgehalte zurückzuführen ist. In westlicher Richtung kommt es, durch Reduktionsvorgänge, zu einer Abnahme der Mineralisation. Im tieferen Bereich der Rinne und in den oberoligozänen Schichtfolgen läßt sich das Auftreten von alkalihydrogenkarbonathaltigen Wässern erkennen, deren Entstehung auf Ionenaustauschvorgänge zurückzuführen ist. Die Spurenmetallgehalte zeigen im Grundwasser der tertiären Schichtfolgen, bedingt durch die auftretenden Gesteine, für die Elemente Aluminium, Kupfer und Zink deutlich höhere mittlere Gehalte. Die gegenüber dem Grundwasser der oberoligozänen Schichtfolgen höheren mittleren Bor-, Kupfer- und Nickelgehalte im Grundwasser der miozänen Schichten stehen in Verbindung mit der primären Anreicherung dieser Elemente in den organischen Ablagerungen des Miozäns. Für das Auftreten der Elemente Chrom (III), Strontium und Eisen lassen sich keine Unterschiede zwischen dem tiefen und dem oberflächennahen Grundwasserleiter erkennen.

Description: The quality of groundwater and hydrogeological relationships of the northern part of the town of Berlin (West), a catchment area of the upper part of the river Havel, were investigated. The observed groundwater System belongs to the stratas above the middle oligocene "Septarienton", in the normal sequence of upper oligocene, miocene and pleistocene. The thicknesses of the occuring layers are influenced by a salt dorne in the NE and a rim syncline in the W, caused by salt tectonics. Consequently the greatest thickness (~380m) is found in the Western part of the investigated area. The pleistocene deposits obtain their greatest thickness in the area of an erosion channel which is in the middle of the investigated area, incised into the middle oligocene Septarienton. The investigations of the relations between artesian head and groundwater flow of the deeper confi ned groundwater in the tertiary strata and of the upper aquifer proved a groundwater flow mainly in southwestern direction. The potential differences between the upper and the confined groundwater shows in the areas of ground-water lowering a relative rising of the hydrostatic pressure of the deeper groundwater. The higher artesian head of the deeper groundwater points to a rise of deeper groundwater, dependent on the permeability of the less permeable layers. This is confi rmed by the results of the geothermical investigations, which show a great positiv geothermal anomal y for these areas. The Chemical composition of the investigated groundwater shows a decreasing total mineral isation with increasing depth. The average total -mineral isation of the deeper groundwater of 15.07 mval/1 lies beneath the level of the groundwater of pleistocene layers (17.38 mval/1). Spacial observations of the mineral isation-distribution show a higher mineral isation for the deeper groundwater in the NE- and SE-part of the investigated area, which is mainly based on a higher calcium-sulfat-content. In the W a decrease of mineral isation, caused by reduction processes, can be observed. In the deeper part of the channel and in the upper oligocene layers an occurrence of alkali-hydrogencarbonat-water, caused by ion-exchange reactions, is recognizable. Trace-metalls contents in the groundwater of the tertiary layers have a definite higher average content of the elements Al, Cu and Zn, caused by the occuring Sediments. The concentration of B, Cu and Ni is higher in the groundwater of the miocene layers than in the groundwater of the upper oligocene layers, this is caused by the primary enrichment of these elements in the organic deposits of the miocene. There are no differences recognicable between the upper and the lower aquifers concerning the occurrence of the elements Co(III), Sr and Fe.

Description: Les recherches concernant la composition de l'eau souterraine et les relations hydro-geologiques Interessent la partie nord de la ville de Berlin (Ouest), qui fait partie de l'aire d'al imentation de la Havel superieure. Le Systeme de l'eau souterraine considere englobe les Sediments de l'oligocene superieur, du miocene et du pleistocene, surmontant strati graphiquement les couches de l'oligocene moyen (Septarienton). Les puissances des differentes series strati graphiques sont influencees par un bombement au Nord-Est, du ä une tectonique salifere, et par une zone d'emigration salifere situee a' l’ouest. En consfequence les puissances maximales (environ 380m) apparaissent dans la partie ouest du terrain analyse. Les formations du pleistocene atteignent leur plus grande epaisseur au niveau d'une gouttiere d'erosion pentue, encaissee dans la partie moyenne du terrain analyse jusqu'au Septarienton. L'observation des conditions de pression et d'ecoulement montre, tant pour l'eau souterraine profonde et captive des suites de couches tertiaires, tant pour les aquiferes superieurs, un ecoulement principalement vers le Sud-Ouest. Pour les differences de pression entre les eaux souterraines superieures et captives on note dans les terrains, desquels on preleve beaucoup d'eau, un soulevement relatif de la surface de pression de l'eau souterraine profonde. Le plus haut plan de pression de celle-ci indique donc que les eaux souterraines profondes montent en fonction de la permeabilite des couches accumulees. Ceci est renforce par les resultats des analyses geothermiques, qui montrent une anomal ie geothermique positive sur une grande surface des terrains en question. Les caracteri stiques hydrogeochimiques des eaux souterraines analysees font apparaTtre en general une diminution de la mineral isation totale en fonction de 1 ’augmentation de la profondeur. La mineral isation totale moyenne des eaux profondes souterraines est avec 15.07 mval/1 inferieure ä celle des eaux profondes des couches pleistocenes(17. 38 mval/1). La repartition horizontale de la mineral isation laisse apparaTtre pour les eaux profondes de la partie Nord-Est et Sud-Est du terrain analyse une mineral isation surelevee, qui est due principalement a une haute teneur en Sulfate de calcium. Vers 1 'ouest, la mineral isation diminue par l'effet de processus de rfeduction. Dans les terrains du fond de la gouttiere et dans les series de couches de l'oligocene superieur on remarque l'apparition d'eaux contenant du NaHCOp provenant du processus de changements des ions. Les teneurs de metaux traces dans les eaux souterraines des series tertiaires montrent nettement-conditionne par les roches y apparaissant- des valeurs moyennes elevees pour l’aluminium, le cuivre et le zinc. Les teneurs moyennes en bore, cuivre et nickel des eaux souterraines des couches du miocene, surelevees par rapport aux eaux souterraines des couches de l'oligocene superieur, sont en relation avec l'enrichissement primaire de ces elements dans les gisements organiques du miocene. En ce qui concerne la repartition des eie ments chrome( III), Strontium et fer aucune difference est notable entre les aquiferes profonds et ceux pres de la surface.

Description: thesis

Description: DFG, SUB Göttingen

Description: Das Untersuchungsgebiet der vorliegenden Arbeit ist der westliche und nordwestliche Rand der Adriaplatte bis in den Bereich der Vortiefen nördlich und östlich des Apennins sowie der Kontaktbereich der Adriaplatte zur europäischen Platte im Westalpenbogen und im Gebiet des Ligurischen Meeres. Für dieses Areal werden Aufbau und Struktur der Erdkruste beschrieben.

Description: thesis

Description: DFG, SUB Göttingen

Description: Die Erdkruste und der obere Erdmantel Westeuropas sind in den letzten 30 Jahren intensiv durch refraktionsseismische Messungen erforscht worden. Die Daten und Ergebnisse sind in zahlreichen Arbeiten veröffentlicht worden. Abgesehen von einigen regionalen Zusammenfassungen fehlt bislang jedoch eine überregionale Gesamtdarstellung dieses umfangreichen Materials. Es ist das Ziel dieser Arbeit, die in zahlreichen Publikationen verstreuten Einzeldaten und Ergebnisse zu sammeln, unter einheitlichen Gesichtspunkten auszuwerten und die Ergebnisse in einer Reihe von Karten darzustellen. Aus verschiedenen Publikationen, Forschungsberichten und den Archiven des geophysikalischen Institutes der Freien Universität Berlin wurden insgesamt 360 Sei smogrammon tagen in reduzierter Form (V = 6 km/s) gesammelt.

Description: thesis

Description: DFG, SUB Göttingen

Description: In der vorliegenden Arbeit wurde ein numerisches Verfahren für die zweidimensionale Simulation stationärer Strömung in porösen Medien entwickelt. Dabei können Modelle mit anisotroper Permeabilität und Wärmeleitfähigkeit ebenso berechnet werden wie Modelle in geneigten und gekrümmten Gebieten. Das Verfahren basiert auf einer Finite-Differenzen-Methode mit einem Schema 2. Ordnung (Il'in-Schema). Für das nichtlineare Gleichungssystem wird ein Iterationsansatz mit einer Art Mehrgittermethode verwendet. Um den großen Anwendungsbereich des entwickelten Verfahrens zu demonstrieren, wird es auf zwei unterschiedliche Fragestellungen aus der Hydrothermik und der Schneemetamorphose angewendet.

Description: thesis

Description: DFG, SUB Göttingen

Description: The cartilaginous tubercles of the mantle of the squid Cranchia scabra have been examined with the scanning electron microscope. Some tubercles are small, simple nodules whereas others are large with a complex Maltese cross form. The varying shapes and sizes probably represent a developmental sequence. The possible role of the tubercles is discussed.

Description: Investigations indicate that the Iceland Ice Sheet was reduced in size during MIS 3 but readvanced to the shelf break at the LGM. Retreat occurred very rapidly around 15 k–16 k cal. yr BP. By contrast, the margin of the ice sheet on the East Greenland shelf, north of the Denmark Strait, was at or close to the shelf break during MIS 3 and 2 and retreat starting ∼17 k cal. yr BP. Quantitative X-ray diffraction analysis of the 〈2 mm sediment fraction was undertaken on 161 samples from Iceland and East Greenland diamictons, and from cores on the slopes and margins of the Denmark Strait. Weight% mineralogical data are used in a principal component analysis to differentiate sediments derived from the two margins. The first two PC axes explain 52% of the variance. These associations are used to characterise sediments as being affiliated with (a) Iceland, (b) East Greenland or (c) mixed. The contribution from Iceland becomes prominent during MIS 2. The extensive outcrop of early Tertiary basalts on East Greenland between 68° and 71° N is an alternative source for basaltic clasts and North Atlantic sediments with εNd(0) values close to ±0.

Description: Microbial mats collected at cold methane seeps in the Black Sea carry out anaerobic oxidation of methane (AOM) to carbon dioxide using sulfate as the electron acceptor. These mats, which predominantly consist of sulfate-reducing bacteria and archaea of the ANME-1 and ANME-2 type, contain large amounts of proteins very similar to methyl-coenzyme M reductase from methanogenic archaea. Mass spectrometry of mat samples revealed the presence of two nickel-containing cofactors in comparable amounts, one with the same mass as coenzyme F430 from methanogens (m/z = 905) and one with a mass that is 46 Da higher (m/z = 951). The two cofactors were isolated and purified, and their constitution and absolute configuration were determined. The cofactor with m/z = 905 was proven to be identical to coenzyme F430 from methanogens. For the m/z = 951 species, high resolution ICP-MS pointed to F430 + CH2S as the molecular formula, and LA-ICP-SF MS finally confirmed the presence of one sulfur atom per nickel. Esterification gave two stereoisomeric pentamethyl esters with m/z = 1021, which could be purified by reverse phase HPLC and were subjected to comprehensive NMR analysis, allowing determination of their constitution and configuration as (172S)−172-methylthio-F430 pentamethyl ester and (172R)−172-methylthio-F430 pentamethyl ester. The corresponding diastereoisomeric pentaacids could also be separated by HPLC and were correlated to the esters via mild hydrolysis of the latter. Equilibration of the pentaacids under acid catalysis showed that the (172S) isomer is the naturally occurring albeit thermodynamically less stable one. The more stable (172R) isomer (80% at equilibrium) is an isolation artifact generated under the acidic conditions necessary for the isolation of the cofactors from the calcium carbonate-encrusted mats.

Description: The living coelacanth Latimeria chalumnae has a unique position in world biodiversity which raises important questions about conservation and ethics. Some relevant details of coelacanth biology are summarized, including those obtained by direct observation from submersibles. The importance of the coelacanth for evolutionary theory and palaeontology is shown to be paralleled in cultural, literary and artistic areas of human heritage. Threats to the Comoran coelacanths from artisanal fishing are described and conservation measures discussed in relation to local customs and economies as well as the promotion of tourism to spread a new awareness and concern for coelacanths worldwide.

Description: Two cores were recovered in the southeastern part of Lake Shkodra (Montenegro and Albania) and sampled for identification of tephra layers. The first core (SK13, 7.8 m long) was recovered from a water depth of 7 m, while the second core (SK19, 5.8 m long) was recovered close to the present-day shoreline (water depth of 2 m). Magnetic susceptibility investigations show generally low values with some peaks that in some cases are related to tephra layers. Naked-eye inspection of the cores allowed the identification of four tephra layers in core SK13 and five tephra layers in core SK19. Major element analyses on glass shards and mineral phases allowed correlation of the tephra layers between the two cores, and their attribution to six different Holocene explosive eruptions of southern Italy volcanoes. Two tephra layers have under-saturated composition of glass shards (foiditic and phonolitic) and were correlated to the AD 472 and the Avellino (ca. 3.9 cal. ka BP) eruptions of Somma-Vesuvius. One tephra layer has benmoreitic composition and was correlated to the FL eruption of Mount Etna (ca. 3.4 cal. ka BP). The other three tephra layers have trachytic composition and were correlated to Astroni (ca. 4.2 cal. ka BP), Agnano Monte Spina (ca. 4.5 cal. ka BP) and Agnano Pomici Principali (ca. 12.3 cal. ka BP) eruptions of Campi Flegrei. The ages of tephra layers are in broad agreement with eight 14C accelerator mass spectrometric measurements carried out on plant remains and charcoal from the lake sediments at different depths along the two cores. The recognition of distal tephra layers from Italian volcanoes allowed the physical link of the Holocene archive of Lake Shkodra to other archives located in the central Mediterranean area and the Balkans (i.e. Lake Ohrid). Five of the recognised tephra layers were recognised for the first time in the Balkans area, and this has relevance for volcanic hazard assessment and for ash dispersal forecasting in case of renewed explosive activity from some of the southern Italy volcanoes. Copyright © 2009 John Wiley & Sons, Ltd.

Description: This paper presents a temperature reconstruction of the past 1000 years for Central Europe, based on chronological records. The advantages and limitations of this hermeneutic, text-based approach are discussed and the statistic methodology is introduced. Historical documents represent direct observation of weather and atmospheric conditions with highest temporal resolution available and precise dating. A major advantage of these extensive data is that they allow the reconstruction of large numbers of variables such as winter temperature, precipitation, pressure patterns or climate extremes as well as floods or storms. Within this hermeneutic climatological research approach, even human impacts and social dimensions of climate development can be examined. In order to quantify the historical information, statistical methods are applied, based on an index approach.

Description: The dry weight and the crest length of the upper and lower beak, the length of the radula ribbon, the average width of the base of the six proximal and distal rachidian teeth as well as the total number of these teeth have all been related to the live body weight of octopuses between 1.1 and 4440 g. From any one of these parameters it is possible to estimate the size and approximate age of the animal.

Description: Features of the brain of this oceanic squid have been investigated and related, as far as possible, to its habits and mode of life. The body and arms are much vacuolated for buoyancy and the animal probably lives with the head upwards. The very long whip-like tentacles are not vacuolated and perhaps hang downwards. They are covered by numerous minute pedunculated suckers, perhaps providing a sticky surface. A special nerve running outside the brain carries signals from the arms and tentacles to the magnocellular lobe, which is very large and of complex structure. However, there are no giant cells and the mantle is weak. Propulsion is mainly by the large fins, which are controlled from the magnocellular lobe, presumably using the information from the arms and tentacles.

Description: Meiobenthos densities and higher taxon composition were studied in an active gas seepage area at depths from 182 to 252 m in the submarine Dnieper Canyon located in the northwestern part of the Black Sea. The meiobenthos was represented by Ciliata, Foraminifera, Nematoda, Polychaeta, Bivalvia, Gastropoda, Amphipoda, and Acarina. Also present in the sediment samples were juvenile stages of Copepoda and Cladocera which may be of planktonic origin. Nematoda and Foraminifera were the dominant groups. The abundance of the meiobenthos varied between 2397 and 52,593 ind.·m−2. Maximum densities of Nematoda and Foraminifera were recorded in the upper sediment layer of a permanent H2S zone at depths from 220 to 250 m. This dense concentration of meiobenthos was found in an area where intense methane seeps were covered by methane-oxidizing microbial mats. Results suggest that methane and its microbial oxidation products are the factors responsible for the presence of a highly sulfidic and biologically productive zone characterized by specially adapted benthic groups. At the same time, an inverse correlation was found between meiofauna densities and methane concentrations in the uppermost sediment layers. The hypothesis is that the concentration of Nematoda and Foraminifera within the areas enriched with methane is an ecological compromise between the food requirements of these organisms and their adaptations to the toxic H2S.

Description: An automatic food dispenser was designed for use with Octopus vulgaris Lamarck. One live crab was delivered each time the octopus pulled a white shape attached to the dispenser. The apparatus provided a continuous record of the time and frequency of feeding over periods of up to 15 days.

Description: This paper presents an event stratigraphy based on data documenting the history of vegetation cover, lake-level changes and fire frequency, as well as volcanic eruptions, over the Last Glacial–early Holocene transition from a terrestrial sediment sequence recovered at Lake Accesa in Tuscany (north-central Italy). On the basis of an age–depth model inferred from 13 radiocarbon dates and six tephra horizons, the Oldest Dryas–Bølling warming event was dated to ca. 14 560 cal. yr BP and the Younger Dryas event to ca. 12 700–11 650 cal. yr BP. Four sub-millennial scale cooling phases were recognised from pollen data at ca. 14 300–14 200, 13 900–13 700, 13 400–13 100 and 11 350–11 150 cal. yr BP. The last three may be Mediterranean equivalents to the Older Dryas (GI-1d), Intra-Allerød (GI-1b) and Preboreal Oscillation (PBO) cooling events defined from the GRIP ice-core and indicate strong climatic linkages between the North Atlantic and Mediterranean areas during the last Termination. The first may correspond to Intra-Bølling cold oscillations registered by various palaeoclimatic records in the North Atlantic region. The lake-level record shows that the sub-millennial scale climatic oscillations which punctuated the last deglaciation were associated in central Italy with different successive patterns of hydrological changes from the Bølling warming to the 8.2 ka cold reversal. Copyright © 2006 John Wiley & Sons, Ltd.

Description: The movements of the isolated buccal mass of Octopus vulgaris have been investigated. The beaks undergo rhythmic cycles of activity in the absence of applied stimulation and after electrical stimulation of the inter-buccal connective. Initial opening, closing, retraction and re-opening phases of movement are described. This cycle of movements is taken to resemble those in the intact animal. Anatomical and electrical evidence identifies the superior mandibular muscle as being partly responsible for the closing and retraction phases of movement. The inferior buccal ganglion determines the sequence of these buccal movements, but modification by sensory feed-back from the musculature is also implied. The preparation will allow a closer comparison of the control of movement in cephalopods and gastropods.

Description: Taonius megalops is a neutrally buoyant oceanic squid, very different in form when young and old. The young, has a round, sac-like mantle and relatively long tentacles, while the adult has an elongated cone-like mantle and relatively short tentacles. The transition in shape and form is gradual and has been followed in animals of between 3 and 180 mm dorsal mantle length. Statistical tests on various parameters investigated, both external and internal, revealed good correlation with the dorsal mantle length and confirmed the descriptions of the development of the chromatophores and subocular light organs with growth. It was concluded that these animals, captured in the Atlantic Ocean, all belonged to the species T. megalops Prosch 1849. This study has permitted us to suggest a tentative outline of the life cycle, although no adults were present in the material available.

Description: A crab which has been captured and paralysed by an octopus but retrieved 1 1/2 min later cannot at first be pulled apart by the experimenter: 27 min later it can be dismembered easily. This demonstrates that there is external digestion when Octopus vulgaris feeds upon crabs. However, it is strictly limited at this stage to the arthrodial membrane and the musculo-skeletal attachment mechanisms as the exoskeleton separates at the joints allowing the muscles to be drawn out of the appendages. And yet, two hours after capture, pieces of crab meat are still recognizable in the octopus's stomach. The process of paralysing and cleaning a crab was noticeably slowed after the surgical removal of the radula, salivary papilla or the lateral buccal palps.

Description: The changes in body weight of 12 octopuses, fed on fish or crabs, were followed under laboratory conditions for periods of 1 to 7 1/2 months. The food intake was estimated and compared with the changes in body weight of the octopuses; 25 to 55% of the total intake of food appeared to be incorporated. The range of the average increase in weight over the whole observation period of each of the animals was 1.9 to 7.7g per day (1 to 7 1/2 months); the mean value was 4.8g per day. The effect of changing the diet of small octopuses (fish or crab)was followed for four weeks but there was no evidence that alteration of the diet affected the rate of changes in body weight of animals of more than 47g initial body weight.

Description: Two new cyclic peroxides, 2 and 3, were isolated from a sample of the Norwegian sponge Plakortis simplex. Their structures including relative stereochemistry were elucidated by interpretation of MS and NMR data. Compound 3 exhibited moderate in vitro activity against six solid human tumor cell lines with IC50 values in the range 7−15 μg/mL.

Description: We determined the coordination environment of Zn2+ in aqueous Cl- brines at 25 °C and 300 °C using ab initio molecular dynamics simulations. The ZnCl+ and ZnCl2 complexes exist as pseudo-octahedral ZnClm(H2O)6-m clusters at 25 °C but occur as pseudo-tetrahedral ZnClm(H2O)4-m clusters at 300 °C. The ZnCl3- complex occurs as the pseudo-tetrahedral ZnCl3(H2O)- cluster at 25 and 300 °C. The tetrahedral ZnCl42- complex, however, is the dominant Zn−Cl complex at 25 °C, at least in highly concentrated (7.4 m) Cl- brines. The change in hydration number with temperature for the ZnCl+ and ZnCl2 complexes will complicate extrapolations of solvation energies to hydrothermal conditions using a Born-model-based equation of state.

Description: Diosmetin, 5,7,3′-trihydroxy-4′-methoxyflavone shows chemopreventive, antimutagenic, and antiallergic effects. On the other hand, chrysoeriol, 5,7,4′-trihydroxy-3′-methoxyflavone induced nodABC-lacZ in Rhizobium meliloti. Both of them belong to hydroxymethoxy- flavones. One major difference between diosmetin and chrysoeriol is the substituted position of hydroxyl and methoxyl groups. In order to elucidate the relationships between their structures and activity, one of the first things to be done is the determination of their structures. However, most flavones occur widely in nature, and thus it is difficult to obtain in sufficient amounts from natural sources to identify their structures. Assignments of NMR data of several hydroxymethoxyflavones may help us to identify novel flavonoid compounds isolated from natural sources based on their NMR experiments. Therefore, we report here the complete assignments of 1H and 13C NMR data of 13 hydroxymethoxyflavones.

Description: Reproductive mechanisms in the seven species of the thecosomatous pteropod genus Limacina are described and compared. All species are protandrous hermaphrodites. Five species–L. bulimoides, L. helicina, L. lesueuri, L. retroversa and L. trochiformis–have a similar reproductive anatomy in which the gonoduct leading from the gonad to the common genital pore functions as a seminal vesicle in the male and is elaborated into mucous and albumen glands in the female. The male system consists of a prostate gland and penis connected to the common genital pore by an external ciliary tract. All five species have a free-swimming veliger stage which hatches from free-floating egg masses. Limacina helicoides has the same reproductive anatomy but is ovoviviparous, with embryos retained in capsules in the mucous gland until they are juveniles of 50 mm in shell diameter. Limacina inflata lacks mucous and albumen glands and a penis; a spermatophore formed by the prostate gland is used in aphallic sperm transfer. This species exhibits brood protection with un-encapsulated embryos retained in the mantle cavity until they are released as veligers measuring 0067 mm in diameter. L. inflata is the most abundant of the seven species despite lowered fecundity; reasons for its ecological success are discussed.

Description: The valuable nutraceutical γ-linolenic acid (GLA, (6Z,9Z,12Z)-octadecatrienoic acid) is biosynthesized by a series of regio- and stereoselective dehydrogenation reactions that are catalyzed by a set of enzymes known as fatty acid desaturases. As part of ongoing research into the mechanism of these remarkable catalysts, we have examined the cryptoregiochemistry (site of initial oxidation) of Δ6 desaturation as it occurs in the protozoan Tetrahymena thermophila. Two complementary approaches that address this issue are described. In the first set of experiments, we measured the individual primary deuterium kinetic isotope effects associated with the C−H bond cleavages at C-6 and C-7. Competition experiments using appropriately deuterium-labeled 4-thiasubstrates revealed that a large KIE (kH/kD = 7.1 ± 0.5) was observed for the C−H bond-breaking step at C-6, whereas the C−H bond cleavage at C-7 was insensitive to deuterium substitution (kH/kD = 1.04 ± 0.05). These results point to C-6 as the site of initial oxidation in Δ6 desaturation since the first chemical step in this type of reaction is rupture of a strong, unactivated C−H bond, an energetically difficult process that typically exhibits a large KIE. This conclusion was supported by the results of our second approach, which involved locating the position of the putative diiron oxo oxidant with respect to substrate by monitoring the efficiency of oxo transfer to a series of thia fatty acid probes. Thus only a 6-thia-analogue is converted to significant amounts of the corresponding sulfoxide (9% yield). The absolute configuration of this product was determined to be S using (S)-MPAA as a chiral shift reagent. Taken together, these results point to the abstraction of the C-6 pro S hydrogen as the initial event in Δ6 desaturation as it occurs in T. thermophila.

Description: Destructive macroalgal mass blooms threaten estuarine and coastal ecosystems worldwide. We asked which factors regulate macroalgal bloom intensity, distribution and species composition. In field experiments in the Baltic Sea, we analyzed the relative effects of nutrients, herbivores and algal propagule banks on population development and dominance patterns in two co-occurring bloom-forming macroalgae, Enteromorpha intestinalis and Pilayella littoralis. Both species were highly affected by the combined effects of a propagule bank, herbivory and nutrients. The magnitude of effects varied with season. The propagule bank was an important overwintering mechanism for both algae, and allowed for recruitment two months earlier than recruitment via freshly dispersed propagules. This provided a seasonal escape from intense herbivory and nutrient limitation later in the year. Favored by massive recruitment from the propagule bank, Enteromorpha was the superior space occupier in early spring, thereby reducing recruitment of Pilayella. Elimination of the propagule bank and recruitment via freshly dispersed propagules favored Pilayella. Strong and selective herbivory on Enteromorpha supported Pilayella in the presence, but not in the absence of the propagule bank. Nutrient enrichment in summer counteracted herbivore pressure on Enteromorpha, thereby negatively affecting Pilayella. Herbivore and nutrient effects were more pronounced for early life stages than adult algae. These results show that recruitment processes and forces affecting early life stages at the beginning of the vegetation period determine development and dominance patterns of macroalgal blooms. Herbivores naturally suppress blooms but increasing nutrient enrichment can override this important control mechanism. The propagule bank plays a previously unrecognized role for population and community dynamics.

Description: Myrionecta rubra, a ubiquitous planktonic ciliate, has received much attention due to its wide distribution, occurrence as a red tide organism, and unusual cryptophyte endosymbiont. Although well studied in coastal waters, M. rubra is poorly examined in the open ocean. In the Irminger Basin, North Atlantic, the abundance of M. rubra was 0–5 cells/ml, which is low compared with that found in coastal areas. Distinct patchiness (100 km) was revealed by geostatistical analysis. Multiple regression indicated there was little relationship between M. rubra abundance and a number of environmental factors, with the exception of temperature and phytoplankton biomass, which influenced abundance in the spring. We also improve on studies that indicate distinct size classes of M. rubra; we statistically recognise four significantly distinct width classes (5–16, 12–23, 18–27, 21–33 μm), which decrease in abundance with increasing size. A multinomial logistic regression revealed the main variable correlated with this size distribution was ambient nitrate concentration. Finally, we propose a hypothesis for the distribution of sizes, involving nutrients, feeding, and dividing of the endosymbiont.

Description: Understanding the influence of growth temperature and carbon dioxide (CO2) on seed quality in terms of seed composition, subsequent seedling emergence and early seedling vigour is important under present and future climates. The objective of this study was to determine the combined effects of elevated temperature and CO2 during seed-filling of parent plants on seed composition, subsequent seedling emergence and seedling vigour of red kidney bean (Phaseolus vulgaris). Plants of cultivar ‘Montcalm’, were grown at daytime maximum/nighttime minimum sinusoidal temperature regimes of 28/18 and 34/24 °C at ambient CO2 (350 μmol mol−1) and at elevated CO2 (700 μmol mol−1) from emergence to maturity. Seed size and seed composition at maturity and subsequent per cent emergence, early seedling vigour (rate of development) and seedling dry matter production were measured. Elevated CO2 did not influence seed composition, emergence, or seedling vigour of seeds produced either at 28/18 or 34/24 °C. Seed produced at 34/24 °C had smaller seed size, decreased glucose concentration, but significantly increased concentrations of sucrose and raffinose compared to 28/18 °C. Elevated growth temperatures during seed production decreased the subsequent per cent emergence and seedling vigour of the seeds and seedling dry matter production of seed produced either at ambient or elevated CO2.

Description: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a high spatial resolution analytical method which has been applied to the analysis of silicic tephras. With current instrumentation, around 30 trace elements can be determined from single glass shards as small as ∼ 40 µm, separated from tephra deposits. As a result of element fractionation during the ablation process using a 266 nm laser, a relatively complex calibration strategy is required. Nonetheless, such a strategy gives analyses which are accurate (typically within ±5%) and have an analytical precision which varies from ∼ ±2% at 100 ppm, to ∼ ±15% at 1 ppm. Detection limits for elements used in correlation and discrimination studies are well below 1 ppm. Examples of the application of trace element analysis by LA-ICP-MS in tephra studies are presented from the USA, New Zealand and the Mediterranean. Improvements in instrumental sensitivity in recent years have the potential to lower detection limits and improve analytical precision, thus allowing the analysis of smaller glass shards from more distal tephras. Laser systems operating at shorter wavelengths (e.g. 193 nm) are now more widely available, and produce a much more controllable ablation in glasses than 266 nm lasers. Crater sizes of 〈10 µm are easily achieved, and at 193 nm many of the elemental fractionation issues which mar longer wavelengths are overcome. By coupling a short wavelength laser to a modern ICP-MS it should be possible to determine the trace element composition of glass shards as small as 20 µm and, providing sample preparation issues can be overcome, the determination of the more abundant trace elements in glass shards as small as 10 µm is within instrumental capabilities. This will make it possible to chemically fingerprint tephra deposits which are far from their sources, and will greatly extend the range over which geochemical correlation of tephras can be undertaken.

Description: Absolute barriers to dispersal are not common in marine systems, and the prevalence of planktonic larvae in marine taxa provides potential for gene flow across large geographic distances. These observations raise the fundamental question in marine evolutionary biology as to whether geographic and oceanographic barriers alone can account for the high levels of species diversity observed in marine environments such as coral reefs, or whether marine speciation also operates in the presence of gene flow between diverging populations. In this respect, the ecological hypothesis of speciation, in which reproductive isolation results from divergent or disruptive natural selection, is of particular interest because it may operate in the presence of gene flow. Although important insights into the process of ecological speciation in aquatic environments have been provided by the study of freshwater fishes, comparatively little is known about the possibility of ecological speciation in marine teleosts. In this study, the evidence consistent with different aspects of the ecological hypothesis of speciation is evaluated in marine fishes. Molecular approaches have played a critical role in the development of speciation hypotheses in marine fishes, with a role of ecology suggested by the occurrence of sister clades separated by ecological factors, rapid cladogenesis or the persistence of genetically and ecologically differentiated species in the presence of gene flow. Yet, ecological speciation research in marine fishes is still largely at an exploratory stage. Cases where the major ingredients of ecological speciation, namely a source of natural divergent or disruptive selection, a mechanism of reproductive isolation and a link between the two have been explicitly documented are few. Even in these cases, specific predictions of the ecological hypothesis of speciation remain largely untested. Recent developments in the study of freshwater fishes illustrate the potential for molecular approaches to address specific questions related to the ecological hypothesis of speciation such as the nature of the genes underlying key ecological traits, the magnitude of their effect on phenotype and the mechanisms underlying their differential expression in different ecological contexts. The potential provided by molecular studies is fully realized when they are complemented with alternative (e.g. ecological, theoretical) approaches.

Description: High-performance liquid chromatography-electrospray ionization mass spectrometry was applied to the detection of the iron(III) complexes of the hydroxamate siderophores rhodotoluric acid, deferrioxamine B, and deferrichrome. Separation of the iron(III) complexes was obtained using a polystyrene-divinylbenzene stationary phase. The retention and responses of ferrioxamine and ferrichrome were optimal when a gradient elution program with methanol and 0.1% (v/v) formic acid as the mobile phases was used. These conditions were also suitable for the retention and separation of the uncomplexed ligands. Retention of iron(III) rhodotoluate was improved when formic acid was replaced by the ion-pairing reagent heptafluorobutyric acid (0.1%). Detection limits for the ferric complexes, defined as 3 SD of the lowest determined standard, were 26 nM for iron(III) rhodotoluate, 0.23 nM for ferrioxamine, and 0.40 nM for ferrichrome. A protocol for the solid-phase extraction of these hydroxamate siderophores from seawater was developed and applied to the extraction of siderophores from enriched incubated seawater samples.

Description: High-performance liquid chromatography-electrospray ionization mass spectrometry was applied to the detection of the iron(III) complexes of the hydroxamate siderophores rhodotoluric acid, deferrioxamine B, and deferrichrome. Separation of the iron(III) complexes was obtained using a polystyrene-divinylbenzene stationary phase. The retention and responses of ferrioxamine and ferrichrome were optimal when a gradient elution program with methanol and 0.1% (v/v) formic acid as the mobile phases was used. These conditions were also suitable for the retention and separation of the uncomplexed ligands. Retention of iron(III) rhodotoluate was improved when formic acid was replaced by the ion-pairing reagent heptafluorobutyric acid (0.1%). Detection limits for the ferric complexes, defined as 3 SD of the lowest determined standard, were 26 nM for iron(III) rhodotoluate, 0.23 nM for ferrioxamine, and 0.40 nM for ferrichrome. A protocol for the solid-phase extraction of these hydroxamate siderophores from seawater was developed and applied to the extraction of siderophores from enriched incubated seawater samples.

Description: Groundwater seeps are known to occur in Eckernförde Bay, Baltic Sea. Their discharge rate and dispersion were investigated with a new schlieren technique application, which is able to visualize heterogeneous water parcels with density anomalies down to Drt ¼ 0.049 on the scale of millimeters. With the use of an inverted funnel, discharged fluids can be captured and the outflow velocity can be determined. Overall, 46 stations could be categorized by three different cases: active vent sites, seep-influenced sites, and non-seep sites. New seep locations were discovered, even at shallow near-shore sites, lacking prominent sediment depression, which indicate submarine springs. The detection of numerous seeps was possible and the groundwater-influenced area was defined to be approximately 6.3 km2. Flow rates of between 0.05 and 0.71 l m)2 min)1 were measured. A single focused fluid plume, which was not disturbed by the funnel was recorded and revealed a flux of 59.6 ± 20 ml cm)2 min)1 and it was calculated that this single focused plume would be strong enough to produce a flow rate through the funnel of 1.32 ± 0.44 l m)2 min)1. The effect of different seep-meter funnel sizes is discussed.

Description: Conceptual models predict counteractive effects of herbivores and nutrient enrichment on plant diversity and reversed effects of grazers under different nutrient regimes. I tested these hypotheses in 11 field experiments with periphyton communities in three different aquatic habitats (a highly eutrophic lake, an meso-eutrophic lake, and an meso-eutrophic part of the Baltic Sea coast) and in different seasons. Grazer access and nutrient supply were manipulated in a factorial design. Species richness and evenness were chosen as response variables. Both manipulated factors had significant and contrasting effects on diversity, with variable effect strength between sites and seasons. From the two aspects of diversity, evenness well reflected the changes in community composition. Fertilization tended to increase the dominance of few species and thus to decrease evenness, whereas grazers counteracted these effects by removing dominant life forms. The response of species richness was not as expected, since grazers decreased richness throughout, whereas nutrients had weaker effects but tended to increase richness. Species richness rather reflected changes in periphyton architecture. Grazers reduced algal richness presumably by co-consumption of rare species in the tightly connected periphyton assemblages, whereas enrichment may increase richness by providing more structure via increased dominance of filamentous species. Although grazer and nutrient effects on richness and evenness were opposing, there was no change in the effect of one factor by manipulation of the other.

Description: Phylogenetic analyses, using 482 bp of the mitochondrial 16S rDNA and 461 bp of the control region of 16 Diplodus species and Oblada melanura, Pagellus bogaraveo and Pagellus acarne, all close relatives of Diplodus, identified the two representatives of Pagellus as the sister group of Diplodus. Oblada melanura was confirmed as the sister taxon of D. puntazzo, despite its different dental morphology and ecology. Within the genus Diplodus, three clades were identified, the first containing D. annularis and D. bellottii, the second D. vulgaris and D. prayensis, and the third comprising three subclades. These were formed by O. melanura clustering with D. puntazzo, D. fasciatus with D. cervinus, and by the Diplodus sargus sub-species assemblage which also included the West Atlantic taxa D. argenteus, D. bermudensis, D. holbrooki, and the Red Sea endemic D. noct. All members of the D. sargus assemblage were genetically closely related. Among them, D. sargus lineatus from the Cape Verde islands was resolved as most ancestral branch, pointing to the possibility that the diversification and spread of the D. sargus assemblage originated in this region. The hypothesis of stepwise speciation following colonization events within the D. sargus complex is fully supported by phylogenetic reconstruction.

Description: Quantitative X-ray diffraction analysis of the 〈2mm sediment fraction was carried out on 1257 samples (from the seafloor and 16 cores) from the Iceland shelf west of 188 W. All but one core (B997-347PC) were from transects along troughs on theNW to N-central shelf, an area that in modern and historic times has been affected by drift ice. The paper focuses on the non-clay mineralogy of the sediments (excluding calcite and volcanic glass). Quartz and potassium feldspars occupy similar positions in an R-mode principal component analysis, and oligoclase feldspar tracks quartz; these minerals are used as a proxy for ice-rafted detritus (IRD). Accordingly, the sum of these largely foreign minerals (Q&K) (to Icelandic bedrock) is used as a proxy for drift ice. A stacked, equi-spaced 100 a record is developed which shows both low-frequency trends and higher-frequency events. The detrended stacked record compares well with the flux of quartz (mg cm-2 a-1) at MD99-2269 off N Iceland. The multi-taper method indicated that there are three significant frequencies at the 95% confidence level with periods of ca. 2500, 445 and 304 a. Regime shift analysis pinpoints intervals when there was a statistically significant shift in the average Q&K weight %, and identifies four IRDrich events separated by intervals with lower inputs. There is some association between peaks of IRD input, less dense surface waters (from d18O data on planktonic foraminifera) and intervals of moraine building.

Description: A set of histological characteristics to judge ovarian development was established and used to elaborate morphological criteria of 10 maturity stages of Baltic cod Gadus morhua sampled throughout the annual cycle to represent different macroscopic maturity stages. The applied characteristics confirmed most stages of the macroscopic scale, but the separation of late immature and resting mature females remained imprecise. Atretic vitellogenic oocytes or encapsulated residual eggs identified the resting condition morphologically, but not all ovaries with visible signs of previous spawning showed such features. One ovarian stage that was previously classified as ‘ripening’ was changed to ‘spawning’, owing to the prevalence of hydrated eggs and empty follicles. Ovaries with malfunctions were defined by a separate stage. Macroscopic criteria were revised by comparing the gross anatomy of ovaries with their histology. Female length and gonado-somatic index supported stage definitions, but substantial variation in Fulton's condition factor and the hepato-somatic index rendered these of little use for this purpose. The time of sampling influenced staging accuracy. A female spawner probability function based on the proportion of ripening and ripe specimens in early spring seems to be the most appropriate method to estimate spawner biomass and reproductive potential.

Description: An experimental study was performed to disentangle parental and environmental effects on the growth of Atlantic cod Gadus morhua larvae and juveniles. Eggs were collected during the spawning season from spawning pairs (families) kept separately in specially designed spawning compartments. Newly hatched larvae were released simultaneously into two mesocosms of 2500 and 4400 m3. Larval growth was monitored by sampling over a 10 week period, after which juveniles were transferred to on-growing tanks, where they were tagged and kept for up to 2 years. Maternal origin was determined by individual microsatellite genotyping of the larvae (n = 3949, 24 families) and juveniles (n = 600). The results showed significant positive correlations between egg size and larval size during the whole mesocosm period. Correlations, however, weakened with time and were no longer significant at the first tank-rearing sampling at an age of 9 months. Significant family-specific differences in growth were observed. The coefficient of variation (c.v.) was calculated in order to examine variation in standard length of larvae during the mesocosm period. Inter-family c.v. was on average 69% of intra-family c.v. Differences in zooplankton densities between the two mesocosms were reflected in larval growth, condition factor and c.v. Low food abundance appeared to reduce c.v. and favour growth of larvae that showed relatively slow growth at high food abundance. It is suggested that genetically determined variation in growth potential is maintained by environmental variability.

Description: During peak spawning of sprat Sprattus sprattus in the Baltic Sea in May–June egg specific gravity averaged ±s.d. 1·00858 ± 0·00116 g cm−3 but was significantly higher in the beginning and significantly lower towards the end of the spawning season. A close relationship was found between egg diameter and egg specific gravity (r2 = 0·71). This relationship, however, changed during the spawning season indicating that some other factor was involved causing the decrease in specific gravity during the spawning period. The vertical egg distribution changed during the spawning season: eggs were distributed mainly in the deep layers early in the season, occurred in and above the permanent halocline during peak spawning, and above the halocline towards the end of the spawning season. Consequently, poor oxygen conditions in the deep layers and low temperatures in layers between the halocline and the developing thermocline may affect egg development. Thus, opportunities for egg development vary over the spawning season and among spawning areas, and depending on frequency of saline water inflows into the Baltic Sea and severity of winters, between years

Description: This contribution aims to report the reflections we had with the scientific community during two international workshops on reference materials for stable isotopes in Davos (2002) and Nice (2003). After evaluating the isotopic homogeneity of some existing reference materials, based on either certificates, literature data or specific inter-laboratory rounds, we confirm these as primary reference materials or propose new ones relative to which stable isotope compositions should be reported. We propose DSM-3 for Mg, NIST SRM 915a for Ca, L-SVEC for Li and NBS28 for Si. Cadmium does not yet have a well identified delta zero material, although three commercial mono-elemental Cd solutions have yielded the same isotopic composition relative to one another. In order to scale the linearity of any mass spectrometer, some secondary reference materials are also proposed: Cambridge-1 solution for Mg, the “Münster-Cd” and JEPPIM Cd solutions for Cd and the “Big Batch” silicate for Si. The team from Nancy propose to prepare a mixed spike solution for Li isotopes. Well-characterised natural samples such as ocean or continental waters, diatoms, sponges, rocks and minerals are needed to validate the entire analytical procedure, particularly to take into account the effect of sample mineralisation and of chemical manipulations for elemental separation prior to analysis.

Description: The annual cycle of extreme 1-day precipitation events across the UK is investigated by developing a statistical model and fitting it to data from 689 rain gauges. A generalized extreme-value distribution (GEV) is fit to the time series of monthly maxima, across all months of the year simultaneously, by approximating the annual cycles of the location and scale parameters by harmonic functions, while keeping the shape parameter constant throughout the year. We average the shape parameter of neighbouring rain gauges to decrease parameter uncertainties, and also interpolate values of all model parameters to give complete coverage of the UK. The model reveals distinct spatial patterns for the estimated parameters. The annual mean of the location and scale parameter is highly correlated with orography. The annual cycle of the location parameter is strong in the northwest UK (peaking in late autumn or winter) and in East Anglia (where it peaks in late summer), and low in the Midlands. The annual cycle of the scale parameter exhibits a similar pattern with strongest amplitudes in East Anglia. The spatial patterns of the annual cycle phase suggest that they are linked to the dominance of frontal precipitation for generating extreme precipitation in the west and convective precipitation in the southeast of the UK. The shape parameter shows a gradient from positive values in the east to negative values in some areas of the west. We also estimate 10-year and 100-year return levels at each rain gauge, and interpolated across the UK.

Description: Ecological stoichiometry describes the biochemical constraints of trophic interactions emerging from the different nutrient content and nutrient demand of producers and consumers, respectively. Most research on this topic originates from well-mixed pelagic food webs, whereas the idea has received far less attention in spatially structured habitats. Here, we test how light as well as grazing and nutrient regeneration by consumers affects growth and biomass of benthic primary producers. In the first laboratory experiment, we manipulated grazer presence (two different snail species plus ungrazed control), in the second experiment we factorially combined manipulation of grazer presence and light intensity. We monitored snail and periphyton biomass as well as dissolved and particulate nutrients (nitrogen and phosphorus) over time. Grazers significantly reduced algal biomass in both experiments. Grazers affected periphyton nutrient content depending on the prevailing nutrient limitation and their own body stoichiometry. In the nitrogen (N-) limited first experiment, grazers increased N both in the periphyton and in the water column. The effect was stronger for grazers with lower N-content. In the phosphorus (P-) limited second experiment, grazers increased the P-content of the periphyton, but the grazer with lower N-content had additionally positive effects on algal N. Light reduction did not affect periphyton biomass, but increased chlorophyll-, N- and P-content of the periphyton. These experiments revealed that the indirect effects of grazers on periphyton were bound by stoichiometric constraints of nutrient incorporation and excretion.

Description: Epipelagic pterotracheid heteropods and young cranchiid squids rely primarily on transparency for concealment; yet they have opaque structures, the eyes and visceral organs that compose the visceral nuclei, which can only be camouflaged in other ways. These two groups have achieved convergent solutions to this problem. The visceral nucleus has a narrow and conical shape and a covering layer of iridophores that lies parallel to the surface of the organ. The eyes also have iridophore layers and tapered shapes. A minimal ventral silhouette results when the long axes of the visceral nucleus and eyes are oriented vertically, with the narrowest ends directed downward. In pterotracheids, this is actively achieved by tilting the nucleus and eyes and flexing the body and proboscis. In cranchiids, tilting of the organs alone suffices and adjustments are accomplished much more rapidly than in the pterotracheids.

Description: Metabolomics offers great potential for understanding the metabolic consequences of exposure to chemicals and other stressors in the environment. Biological systems encompass humans exposed to chemicals in the environment as well as the diverse organisms inhabiting an ecosystem and exposed to environmental contaminants. An overall goal of environmental metabolomics is to understand what is metabolomically “normal” or adaptive and what constitutes a threat to human health and the environment.

Description: Coccoliths were studied from the ODP Hole 1002C and core PL07-39PC in the Cariaco Basin. Increases in Emiliania huxleyi are synchronous with decreases of Gephyrocapsa oceanica and vice versa. A new index (GEX) based on the relative abundances of these two taxa is proposed, and correlates with various other proxies. It is shown that GEX can serve as upwelling proxy. This confirms that the Intertropical Convergence Zone shifted north during the Bølling/Allerød, south during the Younger Dryas and back north during the Preboreal. The upwelling proxy shows few discrepancies with the terrigenous record.

Description: A visible tephra horizon in the NGRIP ice core has been identified by geochemical analysis as the Fugloyarbanki Tephra, a widespread marker horizon in marine cores from the Faroe Islands area and the northern North Atlantic. An age of 26 740 ± 390 yr b2k (1s uncertainty) is derived for this tephra according to the new Greenland Ice Core Chronology (GICC05) based on multiparameter counting of annual layers. Detection of this tephra for the first time within the NGRIP ice core provides a key tie-point between marine and ice-core records during the transition between MIS 3 and 2. Identification of this volcanic event within the Greenland records demonstrates the future potential of using tephrochronology to precisely correlate palaeoarchives in widely separated localities that span the last glacial period, as well as providing a potential method for examining the extent of the radiocarbon marine reservoir effect at this time.

Description: A study of the diet of Sepia officinalis and S. elegans in the Ria de Vigo has shown that crustaceans are the most abundant prey in both species, followed by fish. Changes in the food composition of both species occur with growth. The type of prey eaten by the two sexes of these species is very similar. The possibility of trophic competition between juveniles of S. qficinalis and S. elegans is discussed.

Description: A compilation of δ44/40Ca (δ44/40Ca) data sets of different calcium reference materials is presented, based on measurements in three different laboratories (Institute of Geological Sciences, Bern; Centre de Géochimie de la Surface, Strasbourg; GEOMAR, Kiel) to support the establishment of a calcium isotope reference standard. Samples include a series of international and internal Ca reference materials, including NIST SRM 915a, seawater, two calcium carbonates and a CaF2 reference sample. The deviations in δ44/40Ca for selected pairs of reference samples have been defined and are consistent within statistical uncertainties in all three laboratories. Emphasis has been placed on characterising both NIST SRM 915a as an internationally available high purity Ca reference sample and seawater as representative of an important and widely available geological reservoir. The difference between δ44/40Ca of NIST SRM 915a and seawater is defined as -1.88 O.O4%o (δ44/42CaNISTSRM915a/Sw= -0.94 0.07%o). The conversion of values referenced to NIST SRM 915a to seawater can be described by the simplified equation δ44/40CaSa/Sw=δ44/40CaSa/NIST SRM 915a - 1.88 (δ44/42CaSa/Sw=δ44/42CaSa/NIST SRM 915a - 0.94). We propose the use of NIST SRM 915a as general Ca isotope reference standard, with seawater being defined as the major reservoir with respect to oceanographic studies.

Description: Ecosystem resistance to a single stressor relies on tolerant species that can compensate for sensitive competitors and maintain ecosystem processes, such as primary production. We hypothesize that resistance to additional stressors depends increasingly on species tolerances being positively correlated (i.e. positive species co-tolerance). Initial exposure to a stressor combined with positive species co-tolerance should reduce the impacts of other stressors, which we term stress-induced community tolerance. In contrast, negative species co-tolerance is expected to result in additional stressors having pronounced additive or synergistic impacts on biologically impoverished functional groups, which we term stress-induced community sensitivity. Therefore, the sign and strength of the correlation between species sensitivities to multiple stressors must be considered when predicting the impacts of global change on ecosystem functioning as mediated by changes in biodiversity.

Description: Natural communities are constantly changing due to a variety of interacting external processes and the temporal occurrence and intensity of these processes can have important implications for the diversity and structure of marine sessile assemblages. In this study, we investigated the effects of temporal variation in a disturbance regime, as well as the specific timing of events within different regimes, on the composition and diversity of marine subtidal fouling assemblages. We did this in a multi-factorial experiment using artificial settlement tiles deployed at two sites on the North East coast of England. We found that although there were significant effects of disturbances on the composition of assemblages, there were no effects of either the variation in the disturbance regime or the specific timing of events on the diversity or assemblage composition at either site. In contrast to recent implications we conclude that in marine fouling assemblages, the variability in disturbance regimes (as a driving force) is unimportant, while disturbance itself is an important force for structuring robust ecosystems.

Description: Recent experiments, mainly in terrestrial environments, have provided evidence of the functional importance of biodiversity to ecosystem processes and properties. Compared to terrestrial systems, aquatic ecosystems are characterised by greater propagule and material exchange, often steeper physical and chemical gradients, more rapid biological processes and, in marine systems, higher metazoan phylogenetic diversity. These characteristics limit the potential to transfer conclusions derived from terrestrial experiments to aquatic ecosystems whilst at the same time provide opportunities for testing the general validity of hypotheses about effects of biodiversity on ecosystem functioning. Here, we focus on a number of unique features of aquatic experimental systems, propose an expansion to the scope of diversity facets to be considered when assessing the functional consequences of changes in biodiversity and outline a hierarchical classification scheme of ecosystem functions and their corresponding response variables. We then briefly highlight some recent controversial and newly emerging issues relating to biodiversity-ecosystem functioning relationships. Based on lessons learnt from previous experimental and theoretical work, we finally present four novel experimental designs to address largely unresolved questions about biodiversity-ecosystem functioning relationships. These include (1) investigating the effects of non-random species loss through the manipulation of the order and magnitude of such loss using dilution experiments; (2) combining factorial manipulation of diversity in interconnected habitat patches to test the additivity of ecosystem functioning between habitats; (3) disentangling the impact of local processes from the effect of ecosystem openness via factorial manipulation of the rate of recruitment and biodiversity within patches and within an available propagule pool; and (4) addressing how non-random species extinction following sequential exposure to different stressors may affect ecosystem functioning. Implementing these kinds of experimental designs in a variety of systems will, we believe, shift the focus of investigations from a species richness-centred approach to a broader consideration of the multifarious aspects of biodiversity that may well be critical to understanding effects of biodiversity changes on overall ecosystem functioning and to identifying some of the potential underlying mechanisms involved.

Description: Anthecularin (1), a minor sesquiterpene lactone with a novel ring system was isolated from Greek Anthemis auriculata (Asteraceae). Its structure was elucidated by means of NMR, HRMS, and X-ray crystallography. Anthecularin showed antitrypanosomal (IC50 = 10.1 μg/mL) and antiplasmodial activity (IC50 = 23.3 μg/mL) and inhibited two key enzymes of the plasmodial type II fatty acid biosynthesis pathway, PfFabI and PfFabG (IC50 values = 14 and 28.3 μg/mL, respectively). A probable biogenesis of 1 is also proposed and discussed.

Description: Microcionamides A (1) and B (2) have been isolated from the Philippine marine sponge Clathria (Thalysias) abietina. These new linear peptides are cyclized via a cystine moiety and have their C-terminus blocked by a 2-phenylethylenamine group. Their total structures, including absolute stereochemistry, were determined by a combination of spectral and chemical methods. Compound 1 was shown to slowly isomerize about the C-36/C-37 double bond when stored in DMSO. Microcionamides A (1) and B (2) exhibited significant cytotoxicity against the human breast tumor cells lines MCF-7 and SKBR-3 and displayed inhibitory activity against Mycobacterium tuberculosis H37Ra.

Description: The water-soluble part of the methanolic extract from the aerial parts of Scrophularia crypthophila, through chromatographic methods, yielded three new resin glycosides, crypthophilic acids A−C (1−3). Compounds 1−3 are tetraglycosides of (+)-3S,12S-dihydroxypalmitic acid. The structures of these and 10 known compounds were elucidated by spectroscopic and chemical means. All natural resin glycosides known so far have been obtained from Convolvulaceae plants; this is the first report of such glycosides from another, taxonomically unrelated family (Scrophulariaceae).

Description: Two new isomalabaricane triterpenes, stellettin H (1) and stellettin I (2), have been isolated from the marine sponge Rhabdastrella globostellata, collected from the Philippines. Stellettins A−D (3−6), (−)-stellettin E (7), and rhabdastrellic acid-A (8) were also isolated and characterized. Stellettin B (4) and (−)-stellettin E (7) showed selective cytotoxicity toward p21WAF1/Cip1-deficient human colon tumor (HCT-116) cells with IC50 values of 0.043 and 0.039 μM, respectively.

Description: Raf/MEK-1/MAPK cascade inhibitor activity-directed fractionation of the sponge Stylissa massa afforded eight known alkaloids:  aldisine (1), 2-bromoaldisine (2), 10Z-debromohymenialdisine (3), 10E-hymenialdisine (4), 10Z-hymenialdisine (5), hymenin (6), oroidin (7), and 4,5-dibromopyrrole-2-carbonamide (8). Both 4 and 5 showed significant enzyme inhibitory activity (IC50 3 and 6 nM, respectively). Secondary assays identified these compounds as potent MEK-1 inhibitors. Compounds 4 and 5 also inhibited the growth of human tumor LoVo cells.

Description: From the aerial parts of Putoria calabrica, two new flavonol triglycosides were isolated and their structures were elucidated as quercetin-3-O-[α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside]-7-O-β-d-glucopyranoside (1, calabricoside A) and quercetin-3-O-[4‘ ‘‘-O-caffeoyl-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside]-7-O-β-d-glucopyranoside (2, calabricoside B). Additionally, seven iridoid and three lignan glycosides were isolated and characterized. Radical scavenging activities of all compounds were determined by quantifying their effects on luminol-enhanced chemiluminescence in formyl-methionyl-leucyl-phenylalanine (FMLP) stimulated human polymorphonuclear neutrophils (PMNs). Calabricoside A and B showed strong radical scavenging activity with IC50 values of 0.25 and 0.3 μM, respectively.

Description: A new iridoid glucoside, 5β,6β-dihydroxyboschnaloside (1), was isolated from the aerial parts of Euphrasia pectinata. Five known iridoid glucosides, 6β-hydroxyboschnaloside (2), aucubin, euphroside, plantarenaloside, and geniposidic acid, and two known phenylethanoid glycosides, verbascoside (= acteoside) and leucosceptoside A, were also obtained and characterized. The structure of compound 1 was established by spectroscopic evidence.

Description: The effects of dissolved organic compounds on the determination of nanomolar concentrations of Fe(II) have been compared using two luminol-based flow injection chemiluminescence (FI-CL) methods. One used the direct injection of sample into the luminol reagent stream, and the other incorporated on-line solid-phase extraction of the analyte on an 8-hydroxyquinoline microcolumn. The CL signals from analyses of dissolved iron species (Fe(II) and Fe(III)) with model ligands and organic compounds were examined in high-purity water and seawater. The organic compounds included natural reducing agents (e.g., ascorbic acid), nitrogen σ-donor/π-acceptor compounds (e.g., 1,4-dipyridine, protoporphyrin IX), aromatic compounds (e.g., 1,4-dihydroxybenzene), synthetic iron chelators (e.g., EDTA), and natural iron binding compounds (e.g., desferrioxamine B, ferrichrome A). Fe(II) determinations for both luminol FI-CL methods were affected by submicromolar concentrations of redox-active compounds, strong iron binding ligands (i.e., log KFeL > 6), and compounds with electron-donating functional groups in both high-purity water and seawater. This was due to reactions between organic molecules and iron species before and during analysis, rather than chemiluminescence caused by the individual organic compounds. In addition, the effects of strong ligands and size speciation on Fe(II) recoveries from seawater following acidification (pH 2) and reduction (100 μM sodium sulfite) were investigated. © 2005 American Chemical Society.

Description: The increasing environmental pressures on estuarine and coastal waters call for improved monitoring techniques of chemical constituents to aid management decisions. Automated stripping voltammetry is a suitable technique for continuous, near real-time monitoring of trace metals in marine systems. This contribution describes the application of voltammetric monitoring techniques in estuarine and coastal waters of the UK and Spain. The high spatial and temporal resolution of the data obtained, allows a thorough interpretation of the trace metal sources and behaviour. Future trends in this field research include submersible sensors which can be remotely deployed for a period of several weeks.

Description: Archived scales and otoliths constitute a unique source of DNA that potentially enables extension of the temporal scale of genetic studies of fish populations by decades and even centuries. We review recent insights into fish population and conservation genetics obtained using analysis of DNA from archived samples. This involves both new knowledge about demographic parameters and population structure in wild populations and insights into consequences of anthropogenic pressure resulting from over-harvesting, habitat degradation and stocking. We show that the latter category of studies have led to significant changes of management practices. Ongoing improvement of genetic methods will undoubtedly further expand the ability to utilize historical DNA samples. We envisage that temporal comparisons of large numbers of coding genes will lead to novel insights into selective responses of fish populations to anthropogenic challenges, particularly fisheries-induced selection and global warming. However, both acquisition and storage of historical DNA samples can be hurdles to temporal genetic analyses, while degradation and low copy number in historical DNA samples render genetic data from such sources prone to technical artefacts. We summarize recommendations for storage of samples and DNA extraction and provide checklists for validation of genotyping results. Finally, we stress that validation procedures also involve documentation of the time and population of origin of historical samples, and the inferences drawn should account for the technical and statistical uncertainties associated with historical DNA analysis.

Description: Marine and fisheries scientists are increasingly using metapopulation concepts to better understand and model their focal systems. Consequently, they are considering what defines a metapopulation. One perspective on this question emphasizes the importance of extinction probability in local populations. This view probably stems from the focus on extinction in Levins' original metapopulation model, but places unnecessary emphasis on extinction–recolonization dynamics. Metapopulation models with more complex structure than Levins' patch-occupancy model and its variants allow a broader range of population phenomena to be examined, such as changes in population size, age structure and genetic structure. Analyses along these lines are critical in fisheries science, where presence–absence resolution is far too coarse to understand stock dynamics in a meaningful way. These more detailed investigations can, but need not, aim to assess extinction risk or deal with extinction-prone local populations. Therefore, we emphasize the coupling of spatial scales as the defining feature of metapopulations. It is the degree of demographic connectivity that characterizes metapopulations, with the dynamics of local populations strongly dependent upon local demographic processes, but also influenced by a nontrivial element of external replenishment. Therefore, estimating rates of interpopulation exchange must be a research priority. We contrast metapopulations with other spatially structured populations that differ in the degree of local closure of their component populations. We conclude with consideration of the implications of metapopulation structure for spatially explicit management, particularly the design of marine protected area networks.

Description: Penicillium expansum is known for its destructive rot and patulin production in apple juice. According to the literature, P. expansum can, among other compounds, produce citrinin, ochratoxin A, patulin, penitrem A, and rubratoxin B. In this study the qualitative production of metabolites was examined using TLC (260 isolates), HPLC (85 isolates), and MS (22 isolates). The results showed that none of the 260 isolates produced ochratoxin A, penitrem A, or rubratoxin B. However, chaetoglobosin A and communesin B were produced consistently by all 260 isolates. Patulin and roquefortine C were produced by 98% of the isolates. Expansolides A/B and citrinin were detected in 91 and 85% of the isolates, respectively. Chaetoglobosins and communesins were detected in naturally infected juices and potato pulp, whereas neither patulin nor citrinin was found. Because most P. expansum isolates produce patulin, citrinin, chaetoglobosins, communesins, roquefortine C, and expansolides A and B, foods contaminated with this fungus should ideally be examined for chaetoglobosin A as well as patulin.

Description: A critical examination of published data obtained primarily from recent nuclear magnetic resonance spectroscopy, X-ray absorption near-edge structure spectroscopy, electrospray ionization-mass spectrometry, and pyrolysis studies reveals an evolving new view of the molecular structure of soil humic substances. According to the new view, humic substances are collections of diverse, relatively low molecular mass components forming dynamic associations stabilized by hydrophobic interactions and hydrogen bonds. These associations are capable of organizing into micellar structures in suitable aqueous environments. Humic components display contrasting molecular motional behavior and may be spatially segregated on a scale of nanometers. Within this new structural context, these components comprise any molecules intimately associated with a humic substance, such that they cannot be separated effectively by chemical or physical methods. Thus biomolecules strongly bound within humic fractions are by definition humic components, a conclusion that necessarily calls into question key biogeochemical pathways traditionally thought to be required for the formation of humic substances. Further research is needed to elucidate the intermolecular interactions that link humic components into supramolecular associations and to establish the pathways by which these associations emerge from the degradation of organic litter.

Description: Intra‐plate volcanism in western Europe shows statistically significant episodicity during the Quaternary period. By comparing the known ages for eruptions in France and Germany, which are compiled here, with a composite oxygen isotope record, we have investigated the link between this episodic volcanism and the climate record over the last two million years. We show that increased volcanism between 415–400 ka and 17–5 ka correlates with warming phases at the end of the last Weichselian (Devensian) and earlier Elsterian (Anglian) glacial stages. The three significant caldera explosions in the eastern Eifel, Germany, are all associated with warming phases at the onset of interglacials. The growth and decay of nearby ice sheets suggest that surface changes in continental mass distribution during glacial Milankovich cycles could provide a mechanism for this correlation by means of the distal effects of flexural loading on the lithosphere.