Antarctic Paleogene Planktonic Foraminifer Biostratigraphy: ODP Leg 113|Sites 689 and 690

A Revised Tropical to Subtropical Paleogene Planktonic Foraminiferal Zonation

“…This has resulted in a need for independent biostratigraphic zonal schemes to reflect the changing distribution patterns. For instance, although typical (sub )tropical planktonic foraminiferal taxa occur throughout the lower Eocene of the southern Indian Ocean, keel~d morozovellids were restricted to the E4-E5 (as defined below) excursion (Kerguelen Plateau;Huber, 1991;Berggren, 1992), and acarininids and subbotinids characterize the contemporaneous high-latitude, austral South Atlantic assemblages in the absence of keeled morozovellids (Maud Rise; Stott and Kennett, 1990;Huber, 1991; see paper by Huber and Quillevere, this volume). However, by the middle Eocene, austral faunas were characterized by lowdiversity acarininid (A. collactea, A. primitiva), subbotinid (S. angip-;;foides, S. linaperta) and globigerinathekid (abundant G. index) assemblages.…”

“…Jenkins (1971), as part of a larger Cenozoic study, formulated a relatively broad biostratigraphic scheme for the Eocene succession of New Zealand. With the recognition that Paleocene low-latitude, (sub )tropical zonations are not fully applicable at high latitudes, Stott and Kennett (1990) developed a zonal biostratigraphy for high austral latitudes (Maud Rise) which also found application in the southern Indian Ocean (Kerguelen Plateau) in studies by Huber (1991) and Berggren (1992). A modified zonation for the Antarctic Paleogene is provided in a companion paper by Huber and Quillevere (this issue).…”

Morphology and Affinity of the Planktonic Foraminifer Cassigerinelloita amekiensis Stolk and Reclassification of Cassigerinelloita Stolk

“…2; see also Li et al, this volume). Stott and Kennett (1990) recorded some similar forms in Hole 689B (Leg 113, Maud Rise, Antarctica) in their Zone AP8, equivalent to tropical Zone P10 (upper part), in Chron 21, about 50 Ma in the chronostratigraphy of Berggren et al (1985). Their specimens, figured as Globigerina!…”

“…Just below this, in the lower part of Zones PU and P10, Guembelitria occurred in southern Australia and in Sites 214 and 264 in the eastern Indian Ocean. Because C. amekiensis disappeared much earlier than the extinction level of Guembelitria at Hole 749B, we now propose a range for C. amekiensis to be within Zone P10, or Zone AP8 (of Stott and Kennett, 1990) in the early middle Eocene (Fig. 2; see also Li et al, this volume).…”

“…A synchronous hiatus has been widely recorded near the early Eocene-middle Eocene boundary in the Southern Oceans (McGowran, 1977;Stott and Kennett, 1990), indicating unstable marine environments (McGowran, 1978).…”