Late Cretaceous to Eocene Planktonic Foraminifera and Stratigraphy of the Leg 15 Sites in the Caribbean Sea

Abstract

Remarks: Globotruncana sigali, G. renzi, G. inornata, Clavihedbergella simplex, Hastigerinoides alexanderi and some species of Globigerinelloides are particularly frequent in this zone. In the upper part some specimens transitional to G. fornicata occur together with G. concavata primitiva. Globotruncana concavata concavata Zone Definition: Interval from the first occurrence of the zonal marker to the first evolutionary occurrence of Globotruncana concavata carinata. Remarks: Most of the species characteristic for the underlying zone become extinct within this zone. G. angusticarinata, G. coronata, G. linneiana, G. lapparenti together with the first representatives of Rugoglobigerina characterize this zone. Globotruncana concavata carinata Zone Definition: Range of the zonal marker. Remarks: This corresponds to the Globotruncana fornicata Zone of Bolli (1957a) and probably to Globotruncana concavata concavata Zone of Barr (1972). G. area has its first occurrence at the base of this zone; G. fornicata is very frequent. G. concavata, G. angusticarinata, G. coronata, Hedbergella delrioensis, Rugoglobigerina pilula do not extend beyond the upper boundary of the zone. No overlap seems to exist with G. elevata and G. concavata group, but this possibility could not be completely excluded because of the poor preservation of the planktonic assemblages of this interval. Globotruncana elevata Zone Definition: Interval with the zonal marker from the first occurrence of the zonal marker to the first occurrence of Globotruncana calcarata. Remarks: In this zone many species have their first occurrence, i.e., G. stuartiformis, Heterohelix pulchra, Pseudoguembelina costulata, Rugoglobigerina rugosa, Globigerinelloides prairiehillensis, and G. yaucoensis. In the uppermost part of the zone G. elevata subspinosa, G. "tricarinata", and Heterohelix punctulata make their first appearance. This zone covers a very long time span. However, we did not find any event to subdivideit. Globotruncana calcarata Zone Definition: Range of the zonal marker. Remarks: Many species have their first occurrence in this zone including G. ventricosa, G. gagnebini, G. subcircumnodifer, G. havanensis, and G. plummerae. "^ ‰ o Earl y ^,. "8-3 Margins= Globotruncana st 2 Globorotalia formosa formosa Zone Definition: Interval with the zonal marker from the first occurrence of Globorotalia aragonensis to the first occurrence of Globigerina taroubaensis. Remarks: The zonal marker is generally not well represented, while G. aragonensis rapidly increases in number. The "spinose-keeled" Globorotaliae and G. soldadoensis group, occurring in the underlying zones, rapidly decrease in abundance while G. intermedia and G. pseudotopilensis become more and more frequent. G. quetra and G. rotundimarginata also occur. The other Eocene zones based on planktonic foraminifera could not be identified in the Caribbean drill sites as this interval yields only very poor foraminiferal assemblages.

A Revised Tropical to Subtropical Paleogene Planktonic Foraminiferal Zonation

“…It is also biostratigraphically, but not nomenclaturally, equivalent to the Morozovella subbotinae-Pseudohastigerina wilcoxensis Partial Range Zone (P6b) of Berggren and Miller (1988). It is approximately the same as the Acarinina wilcoxensis berggreni Partial-range Zone (P7) of Blow (1979), and the Globorotalia edgari Zone of Premoli Silva and Bolli, 1973. It corresponds closely to the Globorotalia rex Zone of Bolli (1957b) and the Globorotalia subbotinae Zone as used extensively in Soviet literature of the post-war years (1950's-1980's Blow, 1979).…”

“…His zonation was subsequently followed by zonal schemes developed for (sub)tropical regions in general by Berggren (1969Berggren ( , 1971b, and modified and redefined by Berggren and Miller (1988), Berggren (in Berggren and others, 1995) and Blow (1969Blow ( , 1979. Premoli Silva and Bolli (1973) made minor changes to the earlier version of Bolii (1957a) with the insertion of the Globorotalia edgari Zone between the Globorotalia velasco ens is Zone (below) and the Globorotalia rex (= G. subbotinae) Zone (above). Comprehensive reviews of Paleogene (sub)tropical zonal biostratigraphy were given by Blow (1979) and Berggren and Miller (1988), and particularly by Toumarkine and Luterbacher (1985).…”

Oxygen- and Carbon-Isotope Variations and Planktonic Foraminifer Depth Habitats, Late Cretaceous to Paleocene, Central Pacific, Deep Sea Drilling Project Sites 463 and 465

“…Sampling across the Cretaceous/Tertiary boundary through the early "G. "eugubina Zone. Samples were zoned according to the zonation of van Hinte (1976) for the Cretaceous, and Premoli- Silva and Bolli (1975) for the Paleocene.…”

Site 494: Middle America Trench Lower Slope

“…Hole 494A Core 28 belongs in the Upper Cretaceous because of its abundant but recrystallized Globotruncana spp., Abathomphalus mayaroensis, Raceguembelina fructicosa, Pseudotextularia elegans, Planoglobulina glabrata, Rugoglobigerina sp., and Heterohelix sp., indicating deposition in the Maestrichtian in the Abathomphalus mayaroensis Zone. These are faunas typical of the Late Cretaceous, and similar assemblages have been noted in warm-water units throughout the Caribbean (e.g., Premoli-Silva and Bolli, 1973).…”