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.

Dinoflagellate cyst species composition of recent surface samples (Appendix)

Dinoflagellate cysts and other organic-walled microfossils have been studied in recent surface sediments from the entire Norwegian-Greenland Sea. More than 30 taxa have been recognized, of which only few show a distinct distribution pattern, and allow description of four assemblages. The occurrence of most taxa is related to the relatively warmer waters of the Norwegian Sea. Algidaspaeridium? minutum s.1., Brigantedinium simplex and Impagidinium? pallidum are the only species showing a preference for colder water masses. Two species, I.? pallidum and Nematosphaeropsis labyrinthus are mainly restricted to the oceanic environment, whereas the other species have also been reported from neritic environments in previous studies. Due to the limited knowledge of the ecological and sedimentological factors influencing the occurrence of dinoflagellate cysts in oceanic environments, their distribution in recent sediments can be only related to surface water masses in a broad sense. Although the distribution of assemblages correlates with specific surface water masses, comparison with assemblages recovered from sediment traps deployed basinwide in the Norwegian-Greenland Sea (Dale and Dale, 1992) revealed some major discrepancies in species composition and percentage abundances. The differences cannot be explained with certainty at the moment, although there is some evidence that transport of dinoflagellate cysts and other fossilizable microplankton in water masses by currents, in sea-ice and sediments may modify the assemblages found in recent oceanic surface sediments from the Norwegian-Greenland Sea.

Dinoflagellate cyst accumulation rates of ODP Hole 146-893A from Santa Barbara Basin

The dinoflagellate cyst record from Ocean Drilling Program Hole 893A, Santa Barbara Basin, southern California, is examined at millennial-scale resolution for the past 40 kyr. Changes in cyst abundance, composition of cyst assemblages, and their diversity reflect major shifts in climate and ocean circulation in the region over this time interval. Throughout the sequence, dinoflagellate cyst assemblages are dominated by heterotrophic dinoflagellates. Brigantedinium spp. and other upwelling-related taxa such as Echinidinium and Protoperidinium americanum are abundant, indicating the continued influence of coastal upwelling on the basin during the late Quaternary. A significant increase in cyst accumulation rates is seen during the Holocene and, to a lesser extent, during shorter warming events such as Bolling/Allerod and Dansgaard-Oeschger interstadials, implying enhanced marine productivity during these periods. Cyst diversity is high during the Holocene. An increase in abundance of cysts produced by autotrophic dinoflagellates in the late Holocene suggests enhanced input of warm, nutrient-rich waters. In contrast, cyst assemblages from the Last Glacial Maximum exhibit a relatively low diversity and an increase in the cysts of heterotrophic dinoflagellates, in particular Selenopemphix nephroides. The presence of this taxon in association with Brigantedinium spp. implies substantial cooling of surface waters in the Santa Barbara Basin at that time.

Host-parasite relationships of the clover cyst nematode, Heterodera trifolii Goffart /

Cover title.

The measurement of liver circulation by means of the colloid disapperance rate.

Unclassified Health and Biology.

Colloid and polymer science. Kolloid-Zeitschrift & Zeitschrift für Polymere

Mode of access: Internet.

Advances in colloid science,

Vol. II. Scientific progress in the field of rubber and synthetic elastomers, ed. by H. Mark [and] G.S. Whitby.

Colloid chemistry of cellulosic materials /

"Contribution from Forest Service."

Inorganic colloid chemistry,

I. The collidal elements.--II. The hydrous oxides and hydroxides.--III. The colloidal salts.

An introduction to theoretical and applied colloid chemistry, "the world of neglected dimensions,"

Includes bibliographical references and indexes.

Laboratory mannual of colloid chemistry

Mode of access: Internet.

An introduction to theoretical and applied colloid chemistry : "the world of neglected dimensions" /

"This small volume is the literary result of a series of lectures which I gave during the winter of 1913 and 1914 in the United States and Canada upon the invitation of a number of American universities."--Pref.

Alexandrium cyst abundance in Nootka Sound aquaculture and towns

Senior thesis written for Oceanography 445

New dinoflagellate cyst species from the upper Callovian-lower Oxfordian Rigaudella aemula zone, Timor sea, northwestern Australia

Four new species of dinoflagellate cysts are described from Callovian to lower Oxfordian (Jurassic) sediments of the Timor Sea, northwestern Australia. These comprise Evansia? lacryma, Egmontodinium elongatum, Leptodinium? ancoralium, and Nannoceratopsis reticulata. They are rare to common constituents of the Rigaudella aemula dinoflagellate cyst Interval Zone, and may prove useful for regional biostratigraphic correlation. (c) 2005 Elsevier B.V. All rights reserved.