Cretaceous/Tertiary boundary in the North Pacific: planktonic foraminiferal results from deep sea drilling site 577, Shatsky Rise

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6595378

Gerstel, J; Thunell, R

A detailed micropalentologic analysis of sediments from DSDP hole 577 from the Shatsky Rise, North Pacific was undertaken to describe extinction and radiation patterns of planktonic foraminifera in an apparently continuous, undisturbed carbonate sequence spanning the Cretaceous/Tertiary boundary. The Cretaceous/Tertiary boundary was placed at the abrupt last appearance of all large Maastrichtian planktonic foraminifera. Coincident with these extinctions was the presence of a large number of sanadine spherules and an improvement in foraminiferal preservation. Diminutive populations of Guembelitria cretacea and Globigerina eugubina first appeared about 30cm below the boundary and survived the boundary event. Globigerina eugubina increase in size and inflatedness through the Danian. In addition, a large population of aberrative G. eugubina and Eoglobigerina was observed in the Danian, with these forms being characterized by the development of secondary apertures, bullae, and abnormal final chambers. These abnormal morphotypes are considered to be ecophenotypic variants, reflecting ecologic stress or instability in the earliest Cenozoic marine environment.

• Research Organization: Univ. of South Carolina, Columbia (USA)
• OSTI ID: 6595378
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CONTINENTAL SHELF
SEDIMENTS
PACIFIC OCEAN
PLANKTON
BIOLOGICAL EXTINCTION
MORPHOLOGICAL CHANGES
PALEONTOLOGY
CRETACEOUS PERIOD
FORAMINIFERA
MORPHOLOGY
POPULATION DYNAMICS
TERTIARY PERIOD
WELL DRILLING
ANIMALS
AQUATIC ORGANISMS
CENOZOIC ERA
CONTINENTAL MARGIN
DRILLING
GEOLOGIC AGES
INVERTEBRATES
MESOZOIC ERA
MICROORGANISMS
PROTOZOA
SARCODINA
SEAS
SURFACE WATERS
580100* - Geology & Hydrology- (-1989)