Paleocene coccospheres from DSDP Leg 39, Site 356, São Paulo Plateau, S Atlantic Ocean. Journal of Nannoplankton Research, 20(1): 21-29.
Numerous coccospheres representing the two extant families, Coccolithaceae and Prinsiaceae, were observed in 12 Paleocene (NP2 through NP6) samples from DSDP Site 356, and are briefly described (Calcidiscus? sp., Chiasmolithus edentulus, Coccolithus pelagicus, Cruciplacolithus primus, Cruciplacolithus tenuis, Cruciplacolithus sp., Cyclagelosphaera alta, Ericsonia subpertusa, Ericsonia? sp., Futyania petalosa, Markalius cf. Markalius inversus, Prinsius dimorphosus, Sullivania consueta, Sullivania sp., Toweius eminens, Toweius pertusus). Upper Maastrichtian (CC26) and lowermost Danian (NP1) sediments furnished only coccospheres of Watznaueria barnesae, whereas samples covering the zones from NP2 to NP6 exhibited an increased number of different species. The excellent state of preservation of coccoliths from samples 39-356-29-1, 83-85cm (NP2) and 39-356-21-2, 122-123cm (NP5) may be due to rapid deposition, possibly within fecal pellets, and minor diagenetic effects. We conclude that the presence of intact fossil coccospheres occurs if a sediment is rich in well-preserved coccoliths; their observation then depends on an adequate preparation method and the time spent with the scanning electron microscope.
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Hildebrand-Habel, T. & Willems, H., 1997. Calcareous dinoflagellate cysts from the middle Coniacian to upper Santonian chalk facies of Lägerdorf. Courier Forschungsinstitut Senckenberg, 201: 177-199.
From a number of 24 samples of a 90 m thick middle Coniacian to upper Santonian chalk section of Lägerdorf (N Germany), the assemblage of calcareous dinoflagellate cysts has been described systematically and evaluated quantitatively. Data summarizing information on the distribution of 26 taxa within three subfamilies (Pithonelloideae, Obliquipithonelloideae, Orthopithonelloideae), on the diversity and frequency of the taxa have been developed from the distribution patterns of the cysts. The tendencies to be recognized in these patterns permit a rough division of the section into three parts, which following other authors may conditionally be related to sea-level changes. The lowest part of the section (koeneni zone, middle Coniacian) may thus indicate a regressive trend, the middle part (late middle Coniacian to early middle Santonian) a transgressive trend, and the upper part of the section (middle middle Santonian to upper Santonian) a regressive trend again.
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