ALBERT

Description: In der obersenonen Mastrichter Tuffkreide finden sich kleine Zähne, die durch ihre glatten Kauflächen und die Furchen an den Seiten des oberen Teiles an Kauplatten von Myliobatis erinneren, einen Rochentypus, der ein an durophage Lebensweise angepasstes Gebiss hat. Niemals findet man aber die für diese Familie so typische langgestreckte Form der Zahnplatten; die Zahnoberfläche hat immer rhombische Form. Dames hat eine ausführliche Beschreibung von diesen Zähnen gegeben, die er für Reste eines Cestracion-artigen Namen Rhombodus Binkhorsti Haies hielt, dem er den gab. Ich möchte hier nur noch einige kurze Bemerkungen hinzufügen. Die Abbildungen (fig. 1) zeigen den typischen rhombenförmigen Umriss der Kaufläche (d). Die durch eine in der Richtung der kurzen Diagonale verlaufende, tiefe Rinne in zwei Hälften geteilte Wurzel hat ebenfalls die Gestalt eines Rhombus (fig. 1, b, e). An der Grenze von Krone und Wurzel findet sich an der einen Seite eine Rinne, an der anderen Seite eine vorspringende Leiste (fig. 1 c). Zusammen mit den verticalen Furchen, mit denen die Seiten versehen sind, hat diese Leiste zur Verbindung der Zähne untereinander zu einem Mahlpflaster gedient. Neben dieser regelmässigen Form, die besonders den grösseren Zähnen eigen ist, fanden sich aber Exemplare, die eine Abweichung zeigen, indem nämlich entweder zwei Seiten eines spitzen Winkels des Rhomboïds länger sind wie die beiden anderen, oder das Rhomboïd unsymmetrisch zusammengepresst ist. Es scheint mir, dass dies nicht eine zufällige Variation ist, sondern dass wir gerade durch diese Eigentümlichkeit etwas mehr über die ganze Zusammenstellung des Gebisses erfahren können. Wie ich unten noch näher auseinandersetzen werden, muss man nämlich Rhombodus zu den durophagen Stachelrochen stellen. Bei diesen findet man sehr oft gerade die grössten Zähne in der Mitte des Kiefers. Wenn man nun die Zahl der Zahnreihen, wie es gewöhnlich bei den grosszähnigen Rochen der Fall ist Rhombodus-Unterkiefers zu 7 bis 9 annimmt, so könnte man das Gebiss eines auf eine Weise rekonstruieren, wie es fig. 3 A zeigt, (wobei die verschiedenen obengenannten Formen vorkommen). Es wäre wohl ein grosser Zufall wenn man noch einige Zähne im ursprünglichen Verband finden würde. Wenn einmal die knorpeligen Kiefer aufgelöst sind, bieten die Seitenfurchen nicht genug Festigkeit und fallen die einzelnen Zähne auseinander.

Description: Only one eruption of the island Una-Una (Gulf of Tomini, Northern Celebes), in 1898, has been recorded in historical time; it was described in 1902 by Wichmann (l. c.) after data gathered from different witnesses. No lava flowed out, it was an ash-eruption. During that eruption large mud streams, called lahars, descended along the slope of the volcano and some broad flat-bottomed valleys were eroded (Pl. 44, fig. 4) which are known so very well from some Javanese volcanoes, especially from Mount Kelut. With the latter Una-Una shows many points of resemblance, in shape, structure and in type of the latest eruption. Along one of the large typical lahar valleys we climbed the volcanoe starting near Kololio. Fig. 6 and 7 show the higher parts of our road, typical v-shaped valleys, a product of ordinary water erosion. When seeing such lahar valleys one may presume that the volcano must contain or at least must have contained either a huge crater lake or a filling of loose, sandy, brecciated material strongly impregnated with water. Up to this moment all lava’s, pumice, tuffs and ashes, collected in the island Una-Una are andesitic. The andesite and the andesitic tuffs often show inclusions of carbonated peridotite. It is not impossible that also sediments occur on the island — though on our single trip we did not find them — thus in general structure Una-Una shows some resemblance to the other Togian islands, where, however, the volcanism is now extinct. The crater of the volcano has a diameter of about two kilometers. The textfigure 2 shows a schematic section, a being the western craterrim; b the bottom, consisting of mud, ashes and brecciated volcanic materia] (h) deposited in the crater after the eruption of 1898, thus giving origin to the flat bottom of the caldera-shaped crater. In the central part of the crater is an elevation, c of the same material but strongly metamorphosed by the activity of many solfatara’s which break through it. The author thinks that the elevation and the solfatara’s both owe their origin to a lava plug (g) which after the eruption of 1898 and after the filling up of the crater has penetrated through the crater-pipe and tilted the central part of the crater-bottom, itself not reaching the surface, however, as shown in figure 2 (see also Pl. 44, fig. 5 and Pl. 46, fig. 8). Pl. 46, fig. 9 shows the same phenomenon, a detritus plug in the crater lake of the Kelut volcano, Java. Fig. 2, d is a small crater lake; e is a detritus cone; h is a schematic section through the strato-volcano. In 1901 Professor Molengraaff visited Una-Una and made a fine photograph of the crater, which he kindly gave me for publication (Pl. 46, fig. 8). The activity of solfatara’s was somewhat stronger at the time of his visit; within short intervals a little cloud of smoke escaped from Una-Una, as shown in his sketch (fig. 3). Corals are growing on the submarine slopes in separate colonies. However, no true massive coral reef has been developed, owing to the young erosion stage of this volcanic island; still too large quantities of boulders and smaller detritus material are deposited along the submarine slopes and prevent a more luxurious reef growth.

Description: Behalve uit de koralen, die ik ter plaatse verzameld heb, werd het studiemateriaal samengesteld uit de verzamelingen der Rijks-Geologische Musea der Universiteiten te Leiden, te Utrecht en te Groningen en uit die der Landbouwhoogeschool te Wageningen. Verder uit de collectie van Teyler’s Stichting te Haarlem, van het Natuur-Historische Genootschap in Limburg en de Stadsverzameling in het „Athenaeum”, beiden te Maastricht. Bovendien heb ik de uitgebreide collectie van het Musée Royal d’Histoire Naturelle te Brussel en de origineelen van Goldfuss te Bonn, ter plaatse mogen bestudeeren. Een doorzoeken der Universiteitsverzameling te München en der Technische Hoogeschool te Delft leverde mij geen nieuw materiaal meer. Van elk der beschreven soorten kon ik minstens één goed exemplaar samenbrengen in het Rijks-Geologisch Museum te Leiden, alleen Favia Maastrichtensis wordt te Wageningen bewaard.

Description: Dr. Ph. H. Kuenen kindly entrusted me with a suite of corals collected by him on the island Flores during his cruise with the Expedition on board of H.M. „Willebrord Snellius”. The exact locality is North coast near Papang where the road Papang-Rioeng-Rawoe forkes, 550 m above sea level. Nine different species were collected. Among these is one new species, Fungophyllia millepunctata. Of one coral, a Porites, the species could not be identified with certainty, though it strongly resembles a Porites species from the Miocene Progo-beds of Java. From the other 7 corals the following data on their stratigraphical distribution are known.

Description: De uitgestrekte grindafzettingen der Pleistocene Maas-delta vormen het typische plateaukarakter in het Zuid-Limburgsche landschap. In de dalen, die de latere loop der Maas en haar zijrivieren hierin gesneden hebben, komt in de Zuidelijke helft het Senoon aan den dag. Het grinddek van dit z.g. hoofdterras 1) zakt begrijpelijkerwijze langs de dalhellingen naar beneden en vormt een kapvormige bedekking over het Senoon heen. Waar plaatselijk nog resten van Tertiair (Pliocene-mariene zanden) aanwezig zijn, worden deze zoodoende geheel verborgen en is hun aanwezigheid (in dit gedeelte) alleen uit groeven en boringen bekend. Met uitzondering van enkele diepe groeven op het plateau zelf is dus alleen in de dalen het Senoon ontsloten en wordt daar nog op menige plaats door een dikke laag van jongere grind- en lössafzettingen (midden- en laag terras 1) ) bedekt. Ten Noorden van een strook, die ongeveer van Meerssen naar Kunrade loopt, is dit Senoon tot ongeveer 85 meters verzakt. Deze breukrand is door W. C. Klein in kaart gebracht 2). Van het Senoon komen in Zuid-Limburg de volgende 5 typen voor, die naar plaatsnamen genoemd zijn: Maastrichtsch Tufkrijt (= M) Kunrader formatie (=K) Boven-Senoon Gulpensch krjjt (=G) Groenzand van Vaals (=V) Akensch zand (=A) Onder-Senoon Deze benamingen zullen in het vervolg herhaaldelijk aangeduid worden door de hierboven gegeven afkortingen. Nadat eerst eenige geologische overzichtschetsen gepubliceerd waren (Labry, Binkhorst), verscheen in 1911 een nauwkeurige karteering van het te bespreken gebied, door Uhlenbroek verricht; Maastrichter en Kunrader formatie werden door hem met dezelfde letter en kleur aangegeven, Labry had deze daarentegen van elkaar gescheiden gehouden op zijn geologische schetskaart van Zuid-Limburg.

Description: In the bay of Emmahaven near Padang (W. Sumatra) is a small coral reef. On the North side of this reef a small, sandy island occurs called Pasir Ketjil. It has lately been surrounded by brick walls, besides which a stone pier has been built in a S.W. direction (cf. fig. 1, a map of 1899 and fig. 2 and 3, the present condition). Since the building of that pier, coral sand has accumulated against it on the S-side. This reef lacks shingle ramparts. From this situation of the sandy island with regard to the reef, and from the placing of the younger coral sand accumulations (A in fig. 3), it may be concluded that the maximal wind-effect is strongest from the direction of the open sea, about S.W. Data about the wind frequency kindly supplied by the director of the Kon. Magn. Meteor. Observatorium at Batavia are given on p. 13. From these data have been derived the average wind frequencies per year (p. 15) recorded for 6, 9, 15 and 22 O'clock. The proportions of these data may be seen in the graphs fig. 4, 5, 6 and fig. 7. The monsoons do not occur in the coastal plain of Padang. The wind system in Padang is entirely dominated by land and sea wind but the sea wind is always stronger than the landwind so that it may safely be assumed that the direction of the wind of 9 and 15 O'clock predominates (maximal wind-effect). So it appears to have been the wind effect of the seawind, i. e. the product of the wind frequency given above and the velocity of the wind, about which we lack detailed data here, which we have recognised in the structure and situation of Pasir Ketjil (cf. fig. 2 and 3 with fig. 5 and 6). Although the frequency of the land wind is rather great (fig. 4 and fig. 7) its strength must be very little, for in the structure of Pasir Ketjil no influence, that can be assigned to the land wind, is apparent. We find here at the same time a confirmation of the conclusion we drew some time ago, namely that: data on the wind-frequency only (the prodominant direction of the wind) may sometimes give an indication as to the probable wind effect, but only when the wind in question is not obstructed by mountains. Finally the year-averages of the wind-frequencies of land- and seawind have been taken together in the graph fig. 8. So the part on the right side of the N.S. axis (landwind) can be practically ignored for geological considerations. The structure of the island Poeloe Pasir concurs with that of Pasir Ketjil. Along the coast of Emmahaven occur old and sligthly raised coral limestones. On plate 4 a section of this fossil reef is represented (equal scale for length and height) based on 15 seperate bore-holes; the data have been published by professor Sluiter. From this valuable section we may gather the following particulars: I. The reef has not grown on a rocky volcanic substratum or against the andesitic coastal lavas, but rests entirely on the muddy bottom of the bay, as is also the case with the reefs in he Bay of Batavia, the Thousand-Islands, and the Spermonde Archipelago. II. On the silty bottom rests a layer wherein mud and coral débris have been found. This shows that, in the innitial stage, only a few, branched coral species could grow while the vigorous sedimentation of silt was going on. III. These branched corals gradually attained to larger numbers and formed the basis for the actual, more cohesive reef, which was recognised in the drillings as „coral débris, branched type.” Just as with the reef near Krakatoa (bibl. 5) which grew under the unfavourable influence of strong sedimentation, and with the fossil corals of the Domaring and Menkrawit layers of E. Borneo, which grew under similar circumstances, we see here also that the branched types of growth (unfortunately we are not able to furnish a statement of genera in this case) are the pioneers. In the later, further stages of development of the reef, it is these types again that grow on the outside of the reef (see section of bore holes 9—12). IV. Only in the older stage of development of the reef, bigger globular coral growths appear by the side of the branched varieties. This is again shown by a different indication in the section. V. Later on, to all probability the reef was then already dead and „raised”, hill side waste has fallen over it (section of bore hole 3 and 4). VI. For the sake of clearness I have circumscribed the real, more compact reef with a thick line. Thus it is clearly shown that the basis of the reef, especially in the centre, lies deeper than the adjacent bottom of the bay. Sluiter has tried so explain this by supposing that the reef, when once it was growing into a compact mass has, to a certain extent, gradually sunk into the bottom of the bay. The same phenomenon was noticed while drilling on small islands in the bay of Batavia (bibl. 2). Incidentally I have already pointed out that: „this may be caused „for a large part by aggradation of the bottom as the rivers always „bring a large quantity of silt into the bay.” (bibl. 3, pag. 40). In reality sinking of the reef as well as aggradation of the bottom by a supply of silt in the bay, have probably taken place. Judging from the available data it does not seem possible to me to ascertain the extent of their respective influences. But, the configuration between bore-holes 12—14 and 3—5 of the section given here, as well as the structure and the situation of the island Edam in the bay of Batavia (see bibl. 2, fig. 3) seem to me to point to a real sinking of the reef into the soft bottom. The opportunity to pay a short visit by motor launch to the neighbouring island Poeloe Pisang (besar 1)) happened to present itself (see fig. 9). Against a nucleus of volcanic rock there is, at the South and East side, a plateau of coral limestone bordering on the sea. Part of this limestone has disappeared, probably, in consequence of the marine erosion. In this way a wave-cut rock bench has developed, which, however, is still situated above the normal low-water mark (see section fig. 10). At high tide sea covers this rock bench; the line to which the water then extends is marked by a „storm” rampart of fine white coral shingle. In this area there occur also erosion canals, simmilar to those of Tji Laoet Eureun (S. coast of Java) described at length by Dr. J. Cosijn and the present writer (bibl. 8). See Pl. 2, fig. 13 (breakers in the distance). If we suppose that the reef had originally grown to the level of normal low-water mark, then it follows from the present situation that the amount, either of the sinking of the level of the sea or of the rise of the level of the land, must have been between 3 and 5 metres. The exact determination of this amount was not possible because at the spot where it could have been ascertained best i. e. close to the nucleus of the island, observation was obstructed by débris that had fallen down. We are brought to a simmilar conclusion in Emmahaven itself where in some places (see Pl. 3, fig. 14) effects of abrasion are still to be seen above the present level of the sea. So these observations again support Daly's theory of a recent world wide sinking of the ocean-level.

Description: The results may be summarized as follows: 1. According to Junghuhn and Verbeek the Diëngplateau is the floor of a large caldera, on which the younger volcanoes as G. Pangonan, G. Sipandoe and G. Pakoewadja have been formed. Nothing confirming this theory was found on the spot. 2. On the contrary the supposed large caldera wall was found to consist of separate points of eruption. To the oldest belong the G. Praoe, G. Sidede and G. Bisma, after which the G. Srodja, followed by the G. Sipandoe and G. Pangonan, the terminal craters of the G. Srodja (5—7) and No. 3 of the G. Bisma and finally the Pakoewadja-Kendel mountains were formed. For a fuller account of the often complex history of the various volcanic centres we must refer the reader to the map fig. 8 and the foregoing pages. The „Maaren”: T. Mendjer, T. Warna-Pengilon, T. Teroes and T. Merdada are the largest and finest examples of the many explosion craters. The most striking example of smaller explosion craters occurs to the east of the G. Pangonan as a straight line in a north-south direction developed as an open fissure between T. Loewoek and T. Teroes. The G. Koenir is a lavadome, and probably the G. Prambanan belongs to the same type. 3. The G. Praoe, G. Sipandoe, G. Pangonan and G. Kendil in joining together encircled a basin that had no outlet, in which the water and erosion products of the surrounding slopes collected — at a later stage peat was also formed. The overflow led to the south by the Kali Toelis. Finally a part of this lake was thus converted into dry land, the present Diëngplateau. In a similar manner the T. Tjebong was formed. The G. Srodja, G. Koenir, G. Pakoewadja and the eruption point No. 12 are grouped in such a manner, that they surround a cup-shaped space with no outlet. 4. After the Hindu civilization had disappeared from Java and the ancient city on the Diëngplateau was deserted, the artificial drainage channel, the Gangsiran Swatama, fell into disrepair and became partly choked up by silt. The water level, that had been artificially depressed by the Hindu’s was thus able to rise to its present height.

Description: Op menig eiland van den Indischen Archipel zijn tertiaire bekkens van sterke daling en sedimentatie geconstateerd. In de literatuur is hun veelal de naam geosynclinaal gegeven. Hun geschiedenis kan als een afzonderlijk verschijnsel en als een afgerond onderwerp beschouwd worden, zelfs indien men de geschiedenis dezer tertiaire z.g. geosynclinalen zou willen opvatten als een onderdeel van de zoo veel langer durende en zeer ingewikkelde historie van dit resteerende deel der Tethys. Ofschoon ik hier niet in stratigraphische bijzonderheden zal treden, zal het toch niet te vermijden zjjn, zoo nu en dan bepaalde niveau’s van het tertiair aan te duiden. Ik gebruik hiertoe de bekende letterindeeling van het Indische Tertiair 1).

Description: In thinsections of tertiary limestones from Borneo I studied numerous specimens of a new genus of foraminifera showing an interesting and rather complicated structure. The material belongs to the Geological Survey of the Netherlands East Indies („Dienst van den Mijnbouw in Nederlandsch Indië”) at Bandoeng, Java. Syntypes 1) are in the palaeontological collection of the „Instituut voor Mijnbouwkunde” at Delft. My thanks are due to Mr. A.C. de Jongh, formerly director of the geological survey in the East Indies, who kindly lent me these rocks.

Description: A short time ago I described a new foraminiferal genus from the Tertiary of Borneo 1). I gave this genus the name of Heterospira. Mr. P. H. Oehser of Washington drew my attention to the fact that E. Koken as early as 1896²) had used the name Heterospira for a genus of triassic gastropoda from Hallstatt. Therefore according to the international rules of zoölogical nomenclature, the name Heterospira for a foraminiferal genus being a homonym has to be rejected.