ALBERT

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: 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: Marine methane hydrate in sands has huge potential as an unconventional gas resource; however, no field test of their production potential had been conducted. Here, we report the world’s first offshore methane hydrate production test conducted at the eastern Nankai Trough and show key findings toward future commercial production. Geological analysis indicates that hydrate saturation reaches 80% and permeability in the presence of hydrate ranges from 0.01 to 10 mdarcies. Permeable (1–10 mdarcies) highly hydrate-saturated layers enable depressurization-induced gas production of approximately 20,000 Sm3/D with water of 200 m3/D. Numerical analysis reveals that the dissociation zone expands laterally 25 m at the front after 6 days. Gas rate is expected to increase with time, owing to the expansion of the dissociation zone. It is found that permeable highly hydrate-saturated layers increase the gas–water ratio of the production fluid. The identification of such layers is critically important to increase the energy efficiency and the technical feasibility of depressurization-induced gas production from hydrate reservoirs.

Description: The guest-exchange method (or replacement) for methane production from gas hydrates has recently received attention because it can be used for both carbon dioxide sequestration and methane production. The structure of gas hydrates is maintained as a structure I (sI) hydrate while methane molecules are exchanged with carbon dioxide. In this study, CH4 + CO2 mixed gas hydrates were examined under terahertz light at various temperatures to simulate CH4–CO2 exchange reactions. Each gas hydrate composition examined was a representative composition at each step of the exchange reaction. The molecular composition was also accurately analyzed by gas chromatography. Refractive indices calculated by the terahertz time-domain spectroscopy (THz-TDS) of gas hydrate samples were correlated to the guest composition, and this novel method was proven to be used to quantify the extent of replacement via optical constant. Furthermore, changes in the water framework from the sI hydrate to ice using THz-TDS were investigated with an increasing temperature. Overall, this study reveals the process of guest exchange and phase transition from a gas hydrate to ice via the optical properties in the terahertz region, and it offers a powerful tool in gas hydrate production.

Description: To enable quality control of measurement procedures for determinations of Mg isotope amount ratios, expressed as δ26Mg and δ25Mg values, in Earth-surface studies, the δ26Mg and δ25Mg values of eight reference materials (RMs) were determined by inter-laboratory comparison between five laboratories and considering published data, if available. These matrix RMs, including river water SLRS-5, spring water NIST SRM 1640a, Dead Sea brine DSW-1, dolomites JDo-1 and CRM 512, limestone CRM 513, soil NIST SRM 2709a and vegetation NIST SRM 1515 apple leaves, are representative for a wide range of Earth-surface materials from low-temperature environments. The inter-laboratory variability, 2s (twice the standard deviation), of all eight RMs ranges from 0.05 to 0.17‰ in δ26Mg. Thus, it is suggested that all these materials are suitable for validation of δ26Mg and δ25Mg determinations of Earth-surface geochemical studies.

Description: In the colloidal synthesis of iron sulfides, a series of dialkyl disulfides, alkyl thiols, and dialkyl disulfides (allyl, benzyl, tert-butyl, and phenyl) were employed as sulfur sources. Their reactivity was found to tune the phase between pyrite (FeS2), greigite (Fe3S4), and pyrrhotite (Fe7S8). DFT was used to show that sulfur-rich phases were favored when the C–S bond strength was low in the organosulfurs, yet temperature dependent studies and other observations indicated the reasons for phase selectivity were more nuanced; the different precursors decomposed through different reaction mechanisms, some involving the oleylamine solvent. The formation of pyrite from diallyl disulfide was carefully studied as it was the only precursor to yield FeS2. Raman spectroscopy indicated that FeS2 forms directly without an FeS intermediate, unlike most synthetic procedures to pyrite. Diallyl disulfide releases persulfide (S–S)2– due to the lower C–S bond strength relative to the S–S bond strength, as well as facile decomposition in the presence of amines through SN2′ mechanisms at elevated temperatures.

Description: Fisheries advice is based on demographic calculations, which assume that density-dependent processes regulating recruitment occur only in early life. This assumption is challenged by laboratory and lake studies and some recent indications from marine systems that demonstrate density-dependent regulation late in life. By accounting for spatial dynamics of a population, something that has previously been ignored in models of fish, we show that density-dependent regulation is determined by the size of the habitat: in small habitats, for example small lakes, regulation occurs late in life, while it can occur early in large habitats. When regulation happens late in life, fisheries yield is maximized by exploitation of mainly juvenile fish, while exploiting mature fish maximizes yield if regulation happens early. We review and interpret observations of density dependence in the light of the theory. Our results challenge the current assumption that density dependence always occurs early in life and highlights the need for an increased understanding of density-dependent processes. This can only come about by a change of focus from determining stock-recruitment relationships towards understanding when and how density-dependent regulation occurs in nature.

Description: The spatial structure of species is important for their dynamics and evolution, but also for management and conservation. There are numerous ways of inferring spatial structures, and information from multiple methods is becoming more common to examine how different processes shape the spatial structures of species to improve fish management. Here, we investigate the spatial structure of a suite of Baltic Sea fish species based on the following: (i) spatial (presumably neutral) genetic differentiation, reviewed from the literature, and (ii) spatial synchrony in abundance changes from time series of fishery‐independent surveys, which we currently find to be underused given the amount of data available. For each of these two methods, species were classified as having a distinct, continuous or no/weak spatial structure. In addition, based on each source of information, we estimated the spatial scale of management units for species. The results show that only among species confined to the coastal zone the two sources of information yielded a congruence of the spatial structure (displaying a continuous spatial structure). In contrast, offshore species show weak spatial genetic structure but stronger spatial structure of synchrony in abundance. Based on this, we suggest that population genetic structure and synchrony in abundance should be used as complementary information as they reflect different spatial processes and suggest that management actions should differ with respect to scale depending on the management targets applied. We propose similar analysis should be applied to areas outside the Baltic Sea, and other stock identification methods, to improve management of fish resources.

Description: We report U–Pb zircon ages of c. 700–550 Ma, 262–220 Ma, 47–38 Ma and 15–14 Ma from amphibolites on Naxos Island in the Aegean extensional province of Greece. The zircon has complex internal structures. Based on cathodoluminescence response, zoning and crosscutting relationships a minimum of four zircon growth stages are identified: inherited core, magmatic core, inner metamorphic (?) rim and an outer metamorphic rim. Trace element compositions of the amphibolites suggest igneous differentiation and crustal assimilation. Zircon solubility as a function of saturation temperatures, Zr content and melt composition indicates that the zircon did not originally crystallize in the mafic bodies but was inherited from felsic precursor rocks, and subsequently assimilated into the mafic intrusives during emplacement. Zircon inheritance is corroborated by the complex, xenocrystic nature of the zircon in one sample. Ages of c. 700–550 Ma and 262–220 Ma are assigned to inherited zircon. Available geochemical data suggest that the 15–14 Ma metamorphic rims grew in situ in the amphibolites, corresponding to a high-grade metamorphic event at this time. However, the geochemical data cannot conclusively establish if the c. 40 Ma zircon rims also grew in situ, or whether they were inherited along with the xenocrystic cores. Two scenarios for emplacement of the mafic intrusives are discussed: (i) Intrusion during late-Triassic to Jurassic ocean basin development of the Aegean realm, in which case the 40 Ma zircon rims would have grown in situ, and (ii) emplacement in the Miocene as a result mafic underplating during large-scale extension. In this case, only the 15–14 Ma metamorphic outer rims would have formed in situ in the amphibolitic host rocks.

Description: Populations of fishes provide valuable services for billions of people, but face diverse and interacting threats that jeopardize their sustainability. Human population growth and intensifying resource use for food, water, energy and goods are compromising fish populations through a variety of mechanisms, including overfishing, habitat degradation and declines in water quality. The important challenges raised by these issues have been recognized and have led to considerable advances over past decades in managing and mitigating threats to fishes worldwide. In this review, we identify the major threats faced by fish populations alongside recent advances that are helping to address these issues. There are very significant efforts worldwide directed towards ensuring a sustainable future for the world's fishes and fisheries and those who rely on them. Although considerable challenges remain, by drawing attention to successful mitigation of threats to fish and fisheries we hope to provide the encouragement and direction that will allow these challenges to be overcome in the future.

Description: Japanese flounder, Paralichthys olivaceus, is an economically important marine fish species in Asia. A suite of 18 microsatellite markers chosen from published genetic linkage maps was used to carry out parentage assignments of 188 hatchery-reared juveniles from a small number of breeders. The probabilities of exclusion for the 18 microsatellite markers were 0.604–0.913, and the effectiveness of combined probability of exclusion reached 100% when using the eight microsatellite markers with higher Excl 1 probabilities. The cultured and wild stocks (WSs) were differentiated in a release-recapture population based on these markers. Of the 321 recaptured offspring, 28.34% were assigned to their parental pairs in our broodstock, whereas the remaining offspring could not be traced back to a possible sire or dam. Significant reduction in genetic diversity of the cultured stock (CS) had not been found compared with that of the WS. The results suggest that CSs released into the wild will not adversely affect the genetic structure of natural populations. Our results demonstrate that these markers provide an efficient tool for parentage assignments and genetic analysis of Japanese flounder.

Description: Managing fisheries presents trade-offs between objectives, for example yields, profits, minimizing ecosystem impact, that have to be weighed against one another. These trade-offs are compounded by interacting species and fisheries at the ecosystem level. Weighing objectives becomes increasingly challenging when managers have to consider opposing objectives from different stakeholders. An alternative to weighing incomparable and conflicting objectives is to focus on win–wins until Pareto efficiency is achieved: a state from which it is impossible to improve with respect to any objective without regressing at least one other. We investigate the ecosystem-level efficiency of fisheries in five large marine ecosystems (LMEs) with respect to yield and an aggregate measure of ecosystem impact using a novel calibration of size-based ecosystem models. We estimate that fishing patterns in three LMEs (North Sea, Barents Sea and Benguela Current) are nearly efficient with respect to long-term yield and ecosystem impact and that efficiency has improved over the last 30 years. In two LMEs (Baltic Sea and North East US Continental Shelf), fishing is inefficient and win–wins remain available. We additionally examine the efficiency of North Sea and Baltic Sea fisheries with respect to economic rent and ecosystem impact, finding both to be inefficient but steadily improving. Our results suggest the following: (i) a broad and encouraging trend towards ecosystem-level efficiency of fisheries; (ii) that ecosystem-scale win–wins, especially with respect to conservation and profits, may still be common; and (iii) single-species assessment approaches may overestimate the availability of win–wins by failing to account for trade-offs across interacting species.

Description: Mass fractions of Sn and In were determined in sixteen geological reference materials including basaltic/mafic (BCR‐2, BE‐N, BHVO‐1, BHVO‐2, BIR‐1, OKUM, W‐2, WS‐E), ultramafic (DTS‐2b, MUH‐1, PCC‐1, UB‐N) and felsic/sedimentary reference materials (AGV‐2, JA‐1, SdAR‐M2, SdAR‐H1). Extensive digestion and ion exchange separation tests were carried out in order to provide high yields (〉 90% for Sn, 〉 85% for In), low total procedural blanks (~ 1 ng for Sn, 〈 3 pg for In) and low analytical uncertainties for the elements of interest in a variety of silicate sample matrices. Replicate analyses (n = 2–13) of Sn‐In mass fractions give a combined measurement uncertainty of 2u that are generally 〈 3% and in agreement with literature data, where available. We present the first high precision In data for reference materials OKUM (32.1 ± 1.5 ng g−1), DTS‐2b (2.03 ± 0.25 ng g−1), MUH‐1 (6.44 ± 0.30 ng g−1), and PCC‐1 (3.55 ± 0.35 ng g−1) as well as the first Sn data for MUH‐1 (0.057 ± 0.010 μg g−1) and DTS‐2b (0.623 ± 0.018 μg g−1).

Description: Ecological studies based on time-series often investigate community changes centered on species abundance or biomass but rarely expose the consequential functional aspects underlying such changes. Functional diversity measures have proven to be more accurate predictors for ecosystem functioning than traditional taxonomic approaches and hence gained much attention. There are only limited studies available that analyse the functional implications behind decadal changes of entire communities. We studied zoobenthic communities of two habitats, sheltered and exposed, of a coastal system subject to contrasting changes in community composition over the past four decades. Besides eutrophication and climate-related impacts, the system has been invaded by a non-native polycheate Marenzelleria spp., adding altered functional properties to the communities. The functional dispersion (FDis) metric was used as a measure for comparing the functional diversity of the contrasting habitats, with special focus on the role of Marenzelleria for the entire communities. We highlight changes in the functional identity of the communities, expressed as community-weighted means of trait expression (CWM), using multivariate techniques, and investigate the relationship between taxonomic and functional changes. Despite contrasting community developments in the two habitats, with characteristics traditionally suggesting different environmental quality, we found that the FDis in both habitats remained similar and increased with the introduction of Marenzelleria. Although showing maintained functional diversity across time and space, the functional identity (CWM) of communities changed irrespective of taxonomical differences. Examples include inter alia alterations in palatability proxies, feeding position and sediment transportation types, indicating changed functionality of zoobenthos in coastal systems. We show, when focussing on qualitative functional changes of communities, it is important to evaluate the underlying functional identity, and not only rely on measures of the diversity of functions per se, as the quality indication of expressed functional traits can be concealed when using multi-functionality approaches.

Description: The advent of genomic-, transcriptomic- and proteomic-based approaches has revolutionized our ability to describe marine microbial communities, including biogeography, metabolic potential and diversity, mechanisms of adaptation, and phylogeny and evolutionary history. New interdisciplinary approaches are needed to move from this descriptive level to improved quantitative, process-level understanding of the roles of marine microbes in biogeochemical cycles and of the impact of environmental change on the marine microbial ecosystem. Linking studies at levels from the genome to the organism, to ecological strategies and organism and ecosystem response, requires new modelling approaches. Key to this will be a fundamental shift in modelling scale that represents micro-organisms from the level of their macromolecular components. This will enable contact with omics data sets and allow acclimation and adaptive response at the phenotype level (i.e. traits) to be simulated as a combination of fitness maximization and evolutionary constraints. This way forward will build on ecological approaches that identify key organism traits and systems biology approaches that integrate traditional physiological measurements with new insights from omics. It will rely on developing an improved understanding of ecophysiology to understand quantitatively environmental controls on microbial growth strategies. It will also incorporate results from experimental evolution studies in the representation of adaptation. The resulting ecosystem-level models can then evaluate our level of understanding of controls on ecosystem structure and function, highlight major gaps in understanding and help prioritize areas for future research programs. Ultimately, this grand synthesis should improve predictive capability of the ecosystem response to multiple environmental drivers.

Description: Despite considerable progress in the production of alternative diets, small concentrations of antinutrients remain common in aquaculture nutrition, resulting in a perpetual limitation with regard to the inclusion of plant ingredients in aquafeeds. These compounds are known to impair the general performance of fish when fed for a prolonged period of time, potentially affecting the animal's susceptibility to stress, too. Therefore, a 12-week feeding trial was conducted to examine the chronic effects of purified rapeseed protein concentrate (RPC), containing low concentrations of glucosinolates and phytic acid, on the relative expression of multiple target genes in the liver of juvenile turbot (Psetta maxima, L.). Our results revealed divergent patterns of gene expression, suggesting different coping strategies dependent on the grade of RPC substitution. Data implies increased metabolic rate of turbot fed a 33% RPC-substituted diet due to an upregulation of cytochrome c oxidase mRNA, accompanied by minor adjustments in metabolic pathways. While no signs of reduced welfare were found, data adumbrate a beneficial hormetic reaction. In the highest treatment level (66% RPC), diminished fish condition and reduced growth performance coincided with a downregulation of insulin-like growth factor I, further indicating a potential impaired resistance to stress. An additional downregulation of transferrin hints towards an increased liability to bacterial infections.

Description: The geological development of the Fogo island volcano commenced in the early Quaternary, and much later during the Last Glacial stage this involved a mega-scale lateral collapse of the former edifice. This later event created a large caldera-like landform open to the east, the floor of which is known as the Chã, and subsequently within this a strato-volcanic cone has grown. The last phase of volcanic activity started in late 2014 and persisted for 77 days. It had a devastating impact on the lives of the 1000 plus people who were living within the ‘caldera’, since two large villages and a smaller one were each totally destroyed in a matter of days by the advancing lavas. In addition, large areas of cultivated land, upon which the inhabitants were dependent for their livelihood, were enveloped by lava. The eruption proved to be of a greater magnitude than the immediately preceding one of 1995, when a mass evacuation was necessary but as only a few buildings were affected, resettlement followed. Unfortunately the much greater devastation to the human environment makes it doubtful whether any significant resettlement will be possible after the 2014–2015 event.

Description: Implantable endovascular devices such as bare metal, drug eluting, and bioresorbable stents have transformed interventional care by providing continuous structural and mechanical support to many peripheral, neural, and coronary arteries affected by blockage. Although effective in achieving immediate restoration of blood flow, the long-term re-endothelialization and inflammation induced by mechanical stents are difficult to diagnose or treat. Here we present nanomaterial designs and integration strategies for the bioresorbable electronic stent with drug-infused functionalized nanoparticles to enable flow sensing, temperature monitoring, data storage, wireless power/data transmission, inflammation suppression, localized drug delivery, and hyperthermia therapy. In vivo and ex vivo animal experiments as well as in vitro cell studies demonstrate the previously unrecognized potential for bioresorbable electronic implants coupled with bioinert therapeutic nanoparticles in the endovascular system.

Description: The shrinking-core model of the formation of gas hydrates from ice spheres with well-defined geometry gives experimental access to the gas permeation in bulk hydrates which is relevant to their use as energy storage materials, their exploitation from natural resources, as well as to their role in flow assurance. Here we report on a new approach to model CO2 clathration experiments in the temperature range from 230 to 272 K. We develop a comprehensive description of the gas permeation based on the diffusion along the network of polyhedral cages, some of them being empty. Following earlier molecular dynamics simulation results, the jump from a cage to one of its empty neighbors is assumed to proceed via a “hole-in-cage-wall” mechanism involving water vacancies in cage walls. The rate-limiting process in the investigated temperature range can be explained by the creation of water-vacancy-interstitial pairs. The gas diffusion leads to a time-dependent cage filling which decreases across the hydrate layer with the distance from the particle surface. The model allows a prediction of the time needed for a complete conversion of ice spheres into clathrate as well as the time needed for a full equilibration of the cage fillings. The findings essentially support our earlier results obtained in the framework of a purely phenomenological permeation model in terms of the overall transformation kinetics, yet it provides for the first time insight into the cage equilibration processes. The diffusion of CO2 molecules through bulk hydrate is found to be about three to four times faster in comparison with the CH4 case.

Description: The herbal remedy, milk thistle (Silybum marianum), has been used in traditional medicine for various liver, kidney, and gall bladder ailments. For over a decade, our research group has been investigating the flavonolignans obtained from this medicinal herb for cancer chemoprevention and hepatoprotection.[1–6] Recently, we extended our studies toward examining the diversity as well as distribution patterns of fungal endophytes in leaves, stem, and roots of milk thistle.[7] These fungi inhabit the internal living tissues of the host plants asymptomatically, though they may also cause disease over time.[8] In addition to the phylogenetic profiling of these endophytes, a series of fungal extracts were also examined for chemical composition. Although the plant–endophyte relationship may ormay not be mutualistic, the compounds produced by some endophytes could play a role in the growth and survival of the host. In a previous study, Penicillium restrictum, isolated from milk thistle, yielded promising secondary metabolites.[9] Hence, in pursuit of interesting chemistry, a related monoverticillate endophytic Penicillium sp. was explored.

Description: This paper proposes improved guidelines for dissolved organic matter (DOM) isolation by solid phase extraction (SPE) with a styrene-divinylbenzene copolymer (PPL) sorbent, which has become an established method for the isolation of DOM from natural waters, because of its ease of application and appreciable carbon recovery. Suwannee River water was selected to systematically study the effects of critical SPE variables such as loading mass, concentration, flow rate, and up-scaling on the extraction selectivity of the PPL sorbent. High-field Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and proton nuclear magnetic resonance (H-1 NMR) spectroscopy were performed to interpret the DOM chemical space of eluates, as well as permeates and-wash liquids with molecular resolution. Up to 89% dissolved organic carbon (DOC) recovery was obtained with a DOC/PPL mass ratio of 1:800 at a DOC concentration of 20 mg/L. With the 0 application of larger loading volumes, low proportions of highly oxygenated compounds were retained on the PPL sorbent. The effects of the flow rate on the extraction selectivity of the sorbent were marginal. Up-scaling had a limited effect on the extraction selectivity with the exception of increased self-esterification with a methanol solvent, resulting in methyl ester groups. Furthermore, the SPE/PPL extract exhibited highly authentic characteristics in comparison with original water and reverse osmosis samples. These findings will be useful for reproducibly isolating DOM with representative molecular compositions from various sources and concentrations and minimizing potential inconsistencies among interlaboratory comparative studies.

Description: To estimate the anthropogenic contribution to climate signals in the recent past and future decades implies a certain degree of confidence in both understanding and simulating natural internal variability at interdecadal time scales. If we are to embark on the challenge of decadal prediction, we must be able to mechanistically attribute events to known processes and phenomena, and reproduce their features and statistics within our models. To date, models have succeeded in reproducing only partially spatial patterns, statistics and climatic impacts of interdecadal modes of variability. Reasons for the partial success and agreement among models are to be attributed to the short observational record, the different and complex flavours of coupling between the many subcomponents of the climate system, and the present inability to resolve all climate processes. At an even more fundamental level, this difficulty is aggravated by the limited understanding of the physical mechanisms involved. Here, we review the proposed mechanisms giving rise to interdecadal climate variability, we discuss the hypotheses explaining the main interdecadal modes of variability, and present an overview on the ability and level of agreement in their simulation by the latest generation of coupled climate models. To achieve any progress, the modeling community should focus on both improving the representation and parameterization of key ocean physical processes and obtaining a firmer grasp on the physical mechanisms generating the variability. Both goals can benefit from process studies, intercomparisons with perturbation experiments to study model's sensitivities, and the use of a hierarchy of climate models.

Description: Three monoterpenoid indole alkaloids (MIAs), tabernabovines A–C (1–3), were isolated from Tabernaemontana bovina. They were elucidated by spectroscopic data and computational calculations. Unlike precursors of MIAs, strictosidine and alstrostine A, alkaloid 1 consists of tryptamine and secologanin in a 2:1 ratio. Alkaloid 2 is a cage compound, and 3 possesses a bridged ring. Tabernabovine A exhibited inhibitory activity against NO production with IC50 44.1 μM compared to l-NMMA with IC50 of 48.6 μM.

Description: A synthesis of the 12,12′-azo-analogue of ritterazine N from hecogenin is reported. Ring contraction of two 6/5 bicyclic ring systems, one trans-fused and another spiro, to 5/5 spiro ring systems is accomplished with excellent stereochemical control. Key transformations include an abnormal Baeyer–Villiger oxidation, a Norrish type I cleavage, an intramolecular dipolar [3 + 2] cycloaddition, and an intramolecular oxymecuration. Failing to uncover the β-OH ketone from the isoxazoline ring, we end up with a synthesis of a cyclic analogue of ritterazine N.

Description: The first total synthesis and structure revision of (−)-11β-hydroxycurvularin (1b), a macrolide possessing a β-hydroxyketone moiety, were accomplished. The β-hydroxyketone moiety in this natural product was introduced by cleavage of the N–O bond in an isoxazoline ring that was formed diastereoselectively in a 1,5-remote stereocontrolled fashion by employing intramolecular nitrile oxide cycloaddition

Description: Euphorkanlide A (1), a highly modified ingenane diterpenoid with a C24 appendage forming an additional hexahydroisobenzofuran-fused 19-membered macrocyclic bis-lactone ring system was isolated from the roots of Euphorbia kansuensis. Its structure was determined by extensive spectroscopic analysis and quantum-chemical calculations. Compound 1 showed significant cytotoxicities against a panel of cancer cell lines (IC50s 〈 5 μM). Mechanistic study revealed that 1 could induce the generation of ROS, leading to cell cycle arrest and cell apoptosis in drug-resistant cancer cell line HCT-15/5-FU.

Description: Methane is a powerful greenhouse gas and its biological conversion in marine sediments, largely controlled by anaerobic oxidation of methane (AOM), is a crucial part of the global carbon cycle. However, little is known about the role of iron oxides as an oxidant for AOM. Here we provide the first field evidence for iron-dependent AOM in brackish coastal surface sediments and show that methane produced in Bothnian Sea sediments is oxidized in distinct zones of iron- and sulfate-dependent AOM. At our study site, anthropogenic eutrophication over recent decades has led to an upward migration of the sulfate/methane transition zone in the sediment. Abundant iron oxides and high dissolved ferrous iron indicate iron reduction in the methanogenic sediments below the newly established sulfate/methane transition. Laboratory incubation studies of these sediments strongly suggest that the in situ microbial community is capable of linking methane oxidation to iron oxide reduction. Eutrophication of coastal environments may therefore create geochemical conditions favorable for iron-mediated AOM and thus increase the relevance of iron-dependent methane oxidation in the future. Besides its role in mitigating methane emissions, iron-dependent AOM strongly impacts sedimentary iron cycling and related biogeochemical processes through the reduction of large quantities of iron oxides.

Description: The vast amount of plastic waste emitted into the environment and the increasing concern of potential harm to wildlife has made microplastic and nanoplastic pollution a growing environmental concern. Plastic pollution has the potential to cause both physical and chemical harm to wildlife directly or via sorption, concentration, and transfer of other environmental contaminants to the wildlife that ingest plastic. Small particles of plastic pollution, termed microplastics (〉100 nm and 〈5 mm) or nanoplastics (〈100 nm), can form through fragmentation of larger pieces of plastic. These small particles are especially concerning because of their high specific surface area for sorption of contaminants as well as their potential to translocate in the bodies of organisms. These same small particles are challenging to separate and identify in environmental samples because their size makes handling and observation difficult. As a result, our understanding of the environmental prevalence of nanoplastics and microplastics is limited. Generally, the smaller the size of the plastic particle, the more difficult it is to separate from environmental samples. Currently employed passive density and size separation techniques to isolate plastics from environmental samples are not well suited to separate microplastics and nanoplastics. Passive flotation is hindered by the low buoyancy of small particles as well as the difficulty of handling small particles on the surface of flotation media. Here we suggest exploring alternative techniques borrowed from other fields of research to improve separation of the smallest plastic particles. These techniques include adapting active density separation (centrifugation) from cell biology and taking advantage of surface-interaction-based separations from analytical chemistry. Furthermore, plastic pollution is often challenging to quantify in complex matrices such as biological tissues and wastewater. Biological and wastewater samples are important matrices that represent key points in the fate and sources of plastic pollution, respectively. In both kinds of samples, protocols need to be optimized to increase throughput, reduce contamination potential, and avoid destruction of plastics during sample processing. To this end, we recommend adapting digestion protocols to match the expected composition of the nonplastic material as well as taking measures to reduce and account for contamination. Once separated, plastics in an environmental sample should ideally be characterized both visually and chemically. With existing techniques, microplastics and nanoplastics are difficult to characterize or even detect. Their low mass and small size provide limited signal for visual, vibrational spectroscopic, and mass spectrometric analyses. Each of these techniques involves trade-offs in throughput, spatial resolution, and sensitivity. To accurately identify and completely quantify microplastics and nanoplastics in environmental samples, multiple analytical techniques applied in tandem are likely to be required.

Description: Noninvasive diagnostic by imaging combined with a contrast agent (CA) is by now the most used technique to get insight into human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties, and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticle (SPION)-loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by the triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification, and SPIONs were produced by thermal decomposition during 2, 4, and 6 h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification because of the presence of the selected NEs, for both imaging techniques explored, that is, MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI, and computed tomography.

Description: The spatial structure of species is important for their dynamics and evolution, but also for management and conservation. There are numerous ways of inferring spatial structures, and information from multiple methods is becoming more common to examine how different processes shape the spatial structures of species to improve fish management. Here, we investigate the spatial structure of a suite of Baltic Sea fish species based on the following: (i) spatial (presumably neutral) genetic differentiation, reviewed from the literature, and (ii) spatial synchrony in abundance changes from time series of fishery-independent surveys, which we currently find to be underused given the amount of data available. For each of these two methods, species were classified as having a distinct, continuous or no/weak spatial structure. In addition, based on each source of information, we estimated the spatial scale of management units for species. The results show that only among species confined to the coastal zone the two sources of information yielded a congruence of the spatial structure (displaying a continuous spatial structure). In contrast, offshore species show weak spatial genetic structure but stronger spatial structure of synchrony in abundance. Based on this, we suggest that population genetic structure and synchrony in abundance should be used as complementary information as they reflect different spatial processes and suggest that management actions should differ with respect to scale depending on the management targets applied. We propose similar analysis should be applied to areas outside the Baltic Sea, and other stock identification methods, to improve management of fish resources.

Description: Climatic warming is a primary driver of change in ecosystems worldwide. Here, we synthesize responses of species richness and evenness from 187 experimental warming studies in a quantitative meta-analysis. We asked 1) whether effects of warming on diversity were detectable and consistent across terrestrial, freshwater and marine ecosystems, 2) if effects on diversity correlated with intensity, duration, and experimental unit size of temperature change manipulations, and 3) whether these experimental effects on diversity interacted with ecosystem types. Using multilevel mixed linear models and model averaging, we also tested the relative importance of variables that described uncontrolled environmental variation and attributes of experimental units. Overall, experimental warming reduced richness across ecosystems (mean log-response ratio = –0.091, 95% bootstrapped CI: –0.13, –0.05) representing an 8.9% decline relative to ambient temperature treatments. Richness did not change in response to warming in freshwater systems, but was more strongly negative in terrestrial (–11.8%) and marine (–10.5%) experiments. In contrast, warming impacts on evenness were neutral overall and in aquatic systems, but weakly negative on land (7.6%). Intensity and duration of experimental warming did not explain variation in diversity responses, but negative effects on richness were stronger in smaller experimental units, particularly in marine systems. Model-averaged parameter estimation confirmed these main effects while accounting for variation in latitude, ambient temperature at the sites of manipulations, venue (field versus lab), community trophic type, and whether experiments were open or closed to colonization. These analyses synthesize extensive experimental evidence showing declines in local richness with increased temperature, particularly in terrestrial and marine communities. However, the more variable effects of warming on evenness were better explained by the random effect of site identity, suggesting that effects on species’ relative abundances were contingent on local species composition.

Description: The exploration and proposed mining of sulfide massive deposits in deep-sea environments and increased use deep-sea tailings placement (DSTP) in coastal zones has highlighted the need to better understand the fate and effects of mine-derived materials in marine environments. Metal sulfide ores contain high concentrations of metal(loid)s, of which a large portion exist in highly mineralized or sulfidised forms and are predicted to exhibit low bioavailability. In this study, sediments were spiked with a range of natural sulfide minerals (including chalcopyrite, chalcocite, galena, sphalerite) to assess the bioavailability and toxicity to benthic invertebrates (bivalve survival and amphipod survival and reproduction). The metal sulfide phases were considerably less bioavailable than metal contaminants introduced to sediment in dissolved forms, or in urban estuarine sediments contaminated with mixtures of metal(loid)s. Compared to total concentrations, the dilute-acid extractable metal(loid) (AEM) concentrations, which are intended to represent the more oxidized and labile forms, were more effective for predicting the toxicity of the sulfide mineral contaminated sediments. The study indicates that sediment quality guidelines based on AEM concentrations provide a useful tool for assessing and monitoring the risk posed by sediments impacted by mine-derived materials in marine environments.

Description: UPLC–TOF/MS profiling, followed by the recently reported differential off-line LC–NMR (DOLC–NMR) and quantitative 1H NMR spectroscopy (qHNMR), led to the differential qualitative analysis and accurate quantitation of l-tryptophan-induced metabolome alterations of Penicillium roqueforti, which is typically used in making blue-mold cheese. Among the 24 metabolites identified, two tetrapeptides, namely, d-Phe-l-Val-d-Val-l-Tyr and d-Phe-l-Val-d-Val-l-Phe, as well as cis-bis(methylthio)silvatin, are reported for the first time as metabolites of P. roqueforti. Antimicrobial activity tests showed strong effects of the catabolic l-tryptophan metabolites 3-hydroxyanthranilic acid, anthranilic acid, and 3-indolacetic acid against Saccharomyces cerevisiae, with IC50 values between 15.6 and 24.0 μg/mL, while roquefortine C and cis-bis(methylthio)silvatin inhibited the growth of Gram-negative Escherichia coli and Gram-positive Bacillus subtilis with IC50 values between 30.0 and 62.5 μg/mL.

Description: Viruses play important roles in microbial ecology and some infectious diseases, but relatively little is known about the concentrations, sources, transformation, and fate of viruses in the atmosphere. We have measured total airborne concentrations of virus-like and bacterium-like particles (VLPs between 0.02 and 0.5 μm in size and BLPs between 0.5 and 5 μm) in nine locations: a classroom, a daycare center, a dining facility, a health center, three houses, an office, and outdoors. Indoor concentrations of both VLPs and BLPs were ∼105 particles m–3, and the virus:bacteria ratio was 0.9 ± 0.1 (mean ± standard deviation across different locations). There were no significant differences in concentration between different indoor environments. VLP and BLP concentrations in outdoor air were 2.6 and 1.6 times higher, respectively, than in indoor air. At the single outdoor site, the virus:bacteria ratio was 1.4.

Description: Marine plastic debris is a global environmental problem. Surveys have shown that 〈5 mm plastic particles, known as microplastics, are significantly more abundant in surface seawater and on shorelines than larger plastic particles are. Nevertheless, quantification of microplastics in the environment is hampered by a lack of adequate high-throughput methods for distinguishing and quantifying smaller size fractions (〈1 mm), and this has probably resulted in an underestimation of actual microplastic concentrations. Here we present a protocol that allows high-throughput detection and automated quantification of small microplastic particles (20–1000 μm) using the dye Nile red, fluorescence microscopy, and image analysis software. This protocol has proven to be highly effective in the quantification of small polyethylene, polypropylene, polystyrene, and nylon-6 particles, which frequently occur in the water column. Our preliminary results from sea surface tows show a power-law increase in small microplastics (i.e., 〈1 mm) with a decreasing particle size. Hence, our data help to resolve speculation about the “apparent” loss of this fraction from surface waters. We consider that this method presents a step change in the ability to detect small microplastics by substituting the subjectivity of human visual sorting with a sensitive and semiautomated procedure.

Description: Sediment core PS1904 reveals continuous records of planktic and benthic foraminiferal stable isotopes (δ18O/δ13C) from the north-eastern Greenland continental margin. The data show good comparability with other records from the Nordic Seas, allowing the stratigraphic range of PS1904 to be dated to Marine Isotope Stage (MIS) 6. Focusing on MIS 5 reveals light δ18O values during MIS 5a compared to the last interglacial peak (MIS 5e) which indicates that surface and bottom water layers were strongly affected by freshwater during the former event. We present two possible scenarios explaining the origin and routing of the freshwater: (i) drainage of a Eurasian proglacial lake coupled with the collapse of the Kara Sea Ice Sheet at the MIS 5b/a boundary, and (ii) destabilization and melting of the nearby Greenland Ice Sheet. Although both scenarios could have acted simultaneously, sediment records from the Eurasian sector of the Arctic Ocean hint at the proglacial lake system in north-western Siberia as the largest freshwater source. Regardless of the actual source, the freshwater lowered the surface ocean salinity causing water column stratification and sea ice expansion. Increased sea-ice abundance led to a higher albedo and probably contributed to the cooling and global ice sheet growth that occurred subsequently during MIS 4.

Description: The Ignik Sikumi Gas Hydrate Exchange Field Experiment was conducted by ConocoPhillips in partnership with the U.S. Department of Energy, the Japan Oil, Gas and Metals National Corporation, and the U.S. Geological Survey within the Prudhoe Bay Unit on the Alaska North Slope during 2011 and 2012. The primary goals of the program were to (1) determine the feasibility of gas injection into hydrate-bearing sand reservoirs and (2) observe reservoir response upon subsequent flowback in order to assess the potential for C02 exchange for CH4 in naturally occurring gas hydrate reservoirs. Initial modeling determined that no feasible means of injection of pure C02 was likely, given the presence of free water in the reservoir. Laboratory and numerical modeling studies indicated that the injection of a mixture of C02 and N2 offered the best potential for gas injection and exchange. The test featured the following primary operational phases: (1) injection of a gaseous phase mixture of C02, N2, and chemical tracers; (2) flowback conducted at downhole pressures above the stability threshold for native CH4 hydrate; and ( 3) an extended ( 30-days) flowback at pressures near, and then below, the stability threshold of native CH4 hydrate. The test findings indicate that the formation of a range of mixed-gas hydrates resulted in a net exchange of C02 for CH4 in the reservoir, although the complexity of the subsurface environment renders the nature, extent, and efficiency of the exchange reaction uncertain. The next steps in the evaluation of exchange technology should feature multiple well applications; however, such field test programs will require extensive preparatory experimental and numerical modeling studies and will likely be a secondary priority to further field testing of production through depressurization. Additional insights gained from the field program include the following: (1) gas hydrate destabilization is self-limiting, dispelling any notion of the potential for uncontrolled destabilization; (2) gas hydrate test wells must be carefully designed to enable rapid remediation of wellbore blockages that will occur during any cessation in operations; (3) sand production during hydrate production likely can be managed through standard engineering controls; and ( 4) reservoir heat exchange during depressurization was more favorable than expected-mitigating concerns for near-wellbore freezing and enabling consideration of more aggressive pressure reduction.

Description: Methane recovery from artificial hydrate-bearing sandstones by simulated flue gas swapping was tested using a core flooding experimental setup. Seven groups of experiments were conducted to investigate the effect of hydrate saturation as well as the initial porosity and permeability of sandstones on methane production and carbon dioxide capture. The results show that the CH4 recovery efficiency and the amount of CO2 captured increase with the increase of hydrate saturation at the same initial porosity and permeability of sandstone. The highest CH4 recovery obtained is 51.6% and 99.4% of CO2 in simulated flue gas is sequestered in the hydrate phase after swapping at 9.2 MPa and 277.15 K. Hydrate saturation was 82.5% and the initial porosity and permeability of sandstone are 25.1% and 49 mD, respectively. With the increase of initial porosity and permeability of sandstone, the CH4 recovery efficiency and the amount of CO2 captured increase when other conditions (the hydrate saturation and reaction time) are similar. For investigating the CH4-flue gas swapping mechanism, a micro-differential scanning calorimetry was used to test the heat changes in the whole reaction. No noticeable endothermic or exothermic phenomenon was detected in the CH4-flue gas swapping, which indicates that CH4 hydrate would form mixed hydrates directly instead of going through a dissociation and reformation process. Based on the observed experimental results, a CH4-flue gas swapping mechanism is proposed and the reaction process is found to be essentially controlled by mass transfer.

Description: Microplastics (MPs) in aquatic organisms are raising increasing concerns regarding their potential damage to ecosystems. To date, Raman and Fourier transform infrared spectroscopy techniques have been widely used for detection of MPs in aquatic organisms, which requires complex protocols of tissue digestion and MP separation and are time- and reagentconsuming. This novel approach directly separates, identifies, and characterizes MPs from the hyperspectral image (HSI) of the intestinal tract content in combination with a support vector machine classification model, instead of using the real digestion/separation protocols. The procedures of HSI acquisition ( 1 min) and data analysis (5 min) can be completed within 6 min plus the sample preparation and drying time (30 min) where necessary. This method achieved a promising efficiency (recall 〉98.80%, precision 〉96.22%) for identifying five types of MPs (particles 〉0.2 mm). Moreover, the method was also demonstrated to be effective on field fish from three marine fish species, revealing satisfying detection accuracy (particles 〉0.2 mm) comparable to Raman analysis. The present technique omits the digestion protocol (reagent free), thereby significantly reducing reagent consumption, saving time, and providing a rapid and efficient method for MP analysis.

Description: A new olivine reference material – MongOL Sh11‐2 – for in situ analysis has been prepared from a central portion of a large (20 cm × 20 cm × 10 cm) mantle peridotite xenolith from a ~ 0.5 Ma old basaltic breccia at Shavaryn‐Tsaram, Tariat region, central Mongolia. The xenolith is a fertile mantle lherzolite with minimal signs of alteration. Approximately 10 g of 0.5 to 2 mm gem quality olivine fragments were separated under binocular microscope and analysed by EPMA, LA‐ICP‐MS, SIMS and bulk analytical methods (ID ICP‐MS for Mg and Fe, XRF, ICP‐MS) for major, minor and trace elements at six institutions worldwide. The results show that the olivine fragments are sufficiently homogeneous with respect to major (Mg, Fe, Si) and minor and trace elements. Significant inhomogeneity was revealed only for phosphorus (homogeneity index of 12.4), whereas Li, Na, Al, Sc, Ti and Cr show minor inhomogeneity (homogeneity index of 1–2). The presence of some mineral and fluid‐melt micro‐inclusions may be responsible for the inconsistency in mass fractions obtained by in situ and bulk analytical methods for Al, Cu, Sr, Zr, Ga, Dy and Ho. Here we report reference and information values for twenty‐seven major, minor and trace elements.

Description: Aim: The interdependencies between trophic interactions, environmental factors and anthropogenic forcing determine how species distributions change over time. Large changes in species distributions have occurred as a result of climate change. The objective of this study was to analyse how the spatial distribution of cod and flounder has changed in the Baltic Sea during the past four decades characterized by large hydrological changes. Location: Baltic Sea. Taxon: Cod (Gadus morhua) and flounder (Platichthys flesus). Methods: Catch per unit of effort (CPUE) data for adult and juvenile cod and for adult flounder were modelled using Delta-Generalized additive models including environmental and geographical variables between 1979 and 2016. From the annual CPUE predictions for each species, yearly distribution maps and depth distribution curves were obtained. Mean depth and the depth range were estimated to provide an indication on preferred depth and habitat occupancy. Results: Adult and juvenile cod showed a contraction in their distribution in the southern areas of the Baltic Sea. Flounder, instead, showed an expansion in its distribution with an increase in abundance in the northern areas. The depth distributions showed a progressive shift of the mean depth of occurrence towards shallower waters for adult cod and flounder and towards deeper waters for juvenile cod, as well as a contraction of the species depth ranges, evident mainly from the late 1980s. Main conclusions: Our study illustrates large changes in the spatial distribution of cod and flounder in the Baltic Sea. The changes in depth distribution occurred from the late 1980s are probably due to a combination of expanded areas of hypoxia in deep waters and an increase in predation risk in shallow waters. The net effect of these changes is an increased spatial overlap between life stages and species, which may amplify cod cannibalism and the interaction strength between cod and flounder

Description: Microplastics are ubiquitous across ecosystems, yet the exposure risk to humans is unresolved. Focusing on the American diet, we evaluated the number of microplastic particles in commonly consumed foods in relation to their recommended daily intake. The potential for microplastic inhalation and how the source of drinking water may affect microplastic consumption were also explored. Our analysis used 402 data points from 26 studies, which represents over 3600 processed samples. Evaluating approximately 15% of Americans’ caloric intake, we estimate that annual microplastics consumption ranges from 39000 to 52000 particles depending on age and sex. These estimates increase to 74000 and 121000 when inhalation is considered. Additionally, individuals who meet their recommended water intake through only bottled sources may be ingesting an additional 90000 microplastics annually, compared to 4000 microplastics for those who consume only tap water. These estimates are subject to large amounts of variation; however, given methodological and data limitations, these values are likely underestimates.

Description: Latest knowledge on the reactivity of charged nanoparticulate complexants toward aqueous metal ions is discussed in mechanistic detail. We present a rigorous generic description of electrostatic and chemical contributions to metal ion binding by nanoparticulate complexants, and their dependence on particle size, particle type (i.e., reactive sites distributed within the particle body or confined to the surface), ionic strength of the aqueous medium, and the nature of the metal ion. For the example case of soft environmental particles such as fulvic and humic acids, practical strategies are delineated for determining intraparticulate metal ion speciation, and for evaluating intrinsic chemical binding affinities and heterogeneity. The results are compared with those obtained by popular codes for equilibrium speciation modeling (namely NICA-Donnan and WHAM). Physicochemical analysis of the discrepancies generated by these codes reveals the a priori hypotheses adopted therein and the inappropriateness of some of their key parameters. The significance of the characteristic time scales governing the formation and dissociation rates of metal−nanoparticle complexes in defining the relaxation properties and the complete equilibration of the metal− nanoparticulate complex dispersion is described. The dynamic features of nanoparticulate complexes are also discussed in the context of predictions of the labilities and bioavailabilities of the metal species.

Description: The continental expression of global cooling during the Miocene Climate Transition in Central Asia is poorly documented, as the tectonically active setting complicates the correlation of Neogene regional and global climatic developments. This study presents new geochemical data (CaSO 4 content, carbonate δ 13 C and δ 18 O) from the endorheic alluvial‐lacustrine Aktau succession (Ili Basin, south‐east Kazakhstan) combined with findings from the previously published facies evolution. Time series analysis revealed long‐eccentricity forcing of the paleohydrology throughout the entire succession, split into several facies‐dependent segments. Orbital tuning, constrained by new laser ablation U‐Pb dates and a preexisting magnetostratigraphy, places the succession in a 5.0 Ma long interval in the middle to late Miocene (15.6 to 10.6 Ma). The long‐term water accumulation in the Ili Basin followed the timing of the Miocene Climate Transition, suggesting increased precipitation in the catchment area in response to climate cooling and stronger westerly winds. This was paced by minima of the 2.4 Ma eccentricity cycle, which favored the establishment of a discharge playa (~14.3 Ma) and a perennial lake (12.6 to 11.8 Ma). Furthermore, low obliquity amplitudes (nodes) caused a transient weakening of the westerlies at ~13.7 to 13.5 Ma and at ~12.7 Ma, resulting in negative hydrological budgets and salinization. Flooding of the windward Ili Basin coeval with aridification in the leeward basins suggests that the Tian Shan was a climate boundary already in the middle Miocene. Our results emphasize the impact of climate fluctuations on the westerlies' strength and thus on Central Asian hydrology.