Dinoflagellate Stratigraphy, Leg XI, Deep Sea Drilling Project

Abstract

Dinoflagellate cysts, acritarchs, pollen grains and spores were recovered from both Mesozoic and Cenozoic sections cored during Leg 11. For this report the distribution of dinoflagellates is emphasized. Broad changes of the spore and pollen assemblages are discussed only as they relate to the dinoflagellate stratigraphy. Acritarchs were not studied, although this group is numerically important in local portions of the Mesozoic. Preservation of the dinoflagellates varies from good to excellent, especially in Mesozoic coccolith oozes where relatively uncompressed cysts occur. They are generally well-preserved, also, in those samples where only a few specimens were found. Cysts are most abundant in the coccolith oozes and carbonaceous clays of Mesozoic age cored at Holes 99A, 100, 101 A, and 105. Very few specimens were recovered from the foraminiferal oozes cored at Site 98, and the recrystallized limestones cored at Sites 100 and 105. MESOZOIC DINOFLAGELLATES Dinoflagellates were recovered from most samples of Holes 99A, 100, 101A and 105. They are rare or absent in various samples from Cores 13 and 14 at Hole 99A, Cores 2, 3, 5 and 6 at Hole 100, and Cores 30 through 35 at Hole 105.

Mesozoic Sequences of the Central North Atlantic

“…Deposition occurred well above carbonate Hollister et al (1972) to be of Callovian age and thus to represent the oldest sediments recovered from the North Atlantic. The lowest two sedimentary cores (9 and 10) contain Oxfordian, Callovian, and Bathonian dinoflagellates (Habib, 1972). The calcareous nannoplankton in these cores are Oxfordian or Callovian , but according to Thierstein (in Larson and Hilde, 1975) the nannoplankton may possibly be restricted to the Oxfordian.…”

“…Arenaceous foraminifers, ostracodes, and aptychi are rare (Luterbacher, 1972). Common plant fragments and well-preserved dinoflagellates (Habib, 1972) are enclosed in the limestone. Occasionally thin laminae of silt size peloid grains (Plate 2, Figure 2) occur.…”

Jurassic Sedimentation History of Site 534 (Western North Atlantic) and of the Atlantic-Tethys Seaway

“…Arenaceous foraminifers, globigerinids, ostracodes, radiolarians, and aptychi are rare (Luterbacher, 1972). Common plant fragments and stratigraphically mixed dinoflagellate assemblages (Habib, 1972) are enclosed in the limestones. Millimeter-thick laminae of silt-sized peloid grains, which are considered to represent carbonate turbidites, occur at a few levels.…”

The dinoflagellate cyst genus <i>Polygonifera</i>; emendation and taxonomic stabilization

“…Order Peridiniales Haeckel Suborder Hystrichosphaeridiineae Norris, 1978 Family Senoniasphaeraceae Norris, 1978 Genus Polygonifera Habib, 1972 fig. 4; Remarks.…”