Dinoflagellate cyst abundances at DSDP Site 94-607 from the North Atlantic (Appendix B)

The climatic deterioration related to the onset of Northern Hemisphere glaciations (circa 2.52 Ma BP) must have lead to reorganization and relocation of species associations and may have enhanced species turnover. The present study investigates how this deterioration affects the dinoflagellate cyst and acritarch assemblages from two locations, DSDP Site 607 (North Atlantic) and the Singa section (southern Italy). The records from these locations cover the interval from 2.8 to 2.2 Ma with at least a 5 ka resolution and they have been correlated to the Milankovitch periodicities on a cycle to cycle basis by means of integrated high resolution stable isotope, calcium carbonate, foraminiferal, palynological and magnetostratigraphical datasets. In the present study this high resolution stratigraphic framework is used for a detailed correlation of events occurring in each of the depositional sequences. It also enables further assessment of the palaeoenvironmental preferences of some dinoflagellate cyst forms. Comparison of the two palynological records reveals a close correspondence in the timing of major assemblage changes and extinction events, confirming their Milankovitch cycle based correlation. A close link between periods of Northern Hemisphere cooling (at oxygen isotope stages 110, 104 and 100-96) and increased dinoflagellate cyst turnover appears to be present for both DSDP Site 607 and the Singa section. The turnover events can also be recognized in the records of planktic foraminifera and calcamous nannoplankton. Comparison of the Singa section with Site 607 and with other time equivalent marine palynological data sets, shows that some oceanic taxa respond similarly over a large area. The biostratigraphical implications are discussed. Notably the last occurrence of Invertocystu lucrymosa appears to be a valuable marker for isotope stage 110 in the Mediterranean and North Atlantic.

Grain counts and relative abundances of volcaniclastic sands and sandstones of ODP Leg 180 sites

Modal analysis of middle Miocene to Pleistocene volcaniclastic sands and sandstones recovered from Sites 1108, 1109, 1118, 1112, 1115, 1116, and 1114 within the Woodlark Basin during Leg 180 of the Ocean Drilling Program indicates a complex source history for sand-sized detritus deposited within the basin. Volcaniclastic detritus (i.e., feldspar, ferromagnesian minerals, and volcanic rock fragments) varies substantially throughout the Woodlark Basin. Miocene sandstones of the inferred Trobriand forearc succession contain mafic and subordinate silicic volcanic grains, probably derived from the contemporary Trobriand arc. During the late Miocene, the Trobriand outerarc/forearc (including Paleogene ophiolitic rocks) was subaerially exposed and eroded, yielding sandstones of dominantly mafic composition. Rift-related extension during the late Miocene-late Pliocene led to a transition from terrestrial to neritic and finally bathyal deposition. The sandstones deposited during this period are composed dominantly of silicic volcanic detritus, probably derived from the Amphlett Islands and surrounding areas where volcanic rocks of Pliocene-Pleistocene age occur. During this time terrigenous and metamorphic detritus derived from the Papua New Guinea mainland reached the single turbiditic Woodlark rift basin (or several subbasins) as fine-grained sediments. At Sites 1108, 1109, 1118, 1116, and 1114, serpentinite and metamorphic grains (schist and gneiss) appear as detritus in sandstones younger than ~3 Ma. This is thought to reflect a major pulse of rifting that resulted in the deepening of the Woodlark rift basin and the prevention of terrigenous and metamorphic detritus from reaching the northern rift margin (Site 1115). The Paleogene Papuan ophiolite belt and the Owen Stanley metamorphics were unroofed as the southern margin of the rift was exhumed (e.g., Moresby Seamount) and, in places, subaerially exposed (e.g., D'Entrecasteaux Islands and onshore Cape Vogel Basin), resulting in new and more proximal sources of metamorphic, igneous, and ophiolitic detritus. Continued emergence of the Moresby Seamount during the late Pliocene-early Pleistocene bounded by a major inclined fault scarp yielded talus deposits of similar composition to the above sandstones. Upper Pliocene-Pleistocene sandstones were deposited at bathyal depths by turbidity currents and as subordinate air-fall ash. Silicic glassy (high-K calc-alkaline) volcanic fragments, probably derived from volcanic centers located in Dawson and Moresby Straits, dominated these sandstones.

Relative abundances of planktonic foraminifera from surface sediments of the Drake Passage, Southern Ocean (Table 1)

Based on a qualitative and quantitative evaluation of Recent sediments samples (top 3 cm of cores as well as Petersen grab samples) from the Drake Passage, between South America and Antarctica, the distribution of planktonic foraminifera and their relation to oceanographic conditions was investigated. The Antarctic Convergence - the northern limit of the cold Antarctic Surface Water - is shown to be of major importance in controlling the distributional pattern of planktonic species as well as their total numbers. South of the convergence, Globigerina pachyderma is usually the only species found in the sediment. It occurs with abundances not greater than 6000 per gram dry sediment, and at most stations less than 100 specimens per gram of dry sediment were recovered. At a number of deep-sea stations below 3700 m depth approx. no planktonic foraminifera were found at all. It is most probable, that at least some of these stations are located below the limit of CaCO3 dissolution. North of the Antarctic Convergence planktonic foraminiferal numbers are much higher and range from 1800 to 120000 per gram of dry sediment. Eight species are the major constituents of the population: Globigerina pachyderma, Globigerina bulloides, Globogerina quinqueloba, Globigerina inflata, Globorotalia truncatolinoides, Globorotalia scitula, Globigerinita glutinata and Globigerinita uvula. The widespread occurrence of Globorotalia truncatulinoides, which in the northern hemisphere is usually a subtropical form, is especially noteworthy. Another Globigerina, morphologically similar to G. pachyderma, has been recognized frequently north of the Antarctic Convergence. Globigerina megastoma which has its type area in the Drake Passage, has been found only rarely. Orbulina universa occurs in samples from the areas of higher water temperature around the South American Continent. Globigerina pachyderma is predominantly sinistrally coiled throughout the area investigated, but a slight increase in the percentage of dextrally coiled specimens may be noticed with increasing water temperature, i.e. from south to north.

Sea surface temperature estimates and alkenone C37:4 abundances in ODP Site 145-882 and 177-1090

The cold upwelling 'tongue' of the eastern equatorial Pacific is a central energetic feature of the ocean, dominating both the mean state and temporal variability of climate in the tropics and beyond. Recent evidence for the development of the modern cold tongue during the Pliocene-Pleistocene transition has been explained as the result of extratropical cooling that drove a shoaling of the thermocline. We have found that the sub-Antarctic and sub-Arctic regions underwent substantial cooling nearly synchronous to the cold tongue development, thereby providing support for this hypothesis. In addition, we show that sub-Antarctic climate changed in its response to Earth's orbital variations, from a subtropical to a subpolar pattern, as expected if cooling shrank the warm-water sphere of the ocean and thus contracted the subtropical gyres.

Variable stars in Milton field 54,

Mode of access: Internet.

Variable stars,

"Corrections to index": slip laid in.

Catalogue of bright stars, containing all important data known in June, 1930, relating to all stars brighter than 6.5 visual magnitude, and to some fainter ones.

At head of title: Yale university observatory.

Three stars ... /

Mode of access: Internet.

The peak of the load; the waiting months on the hilltop from the entrance of the Stars and Stripes to the second victory of the Marne.

Mode of access: Internet.

Orbits of the double stars, A B of [Epsilon] Hydrae and ? 883, by the graphical method.

Type-written ms.

Trees, stars and birds : a book of outdoor science /

"List of books" at end of each part.