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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 950

Last Page: 950

Title: Heterobathyal Benthic Foraminifera: Bathymetric Migrations as Oceans Change: ABSTRACT

Author(s): G. P. Lohmann

Article Type: Meeting abstract


Reconstructions of the past distribution of Quaternary deep-water benthic foraminifera from both the Atlantic Ocean and Mediterranean Sea show that the bathymetric range of most common species has changed substantially through time.

An Atlantic Ocean abyssal biofacies characterized by "Epistominella" umbonifera periodically migrated hundreds of meters as ice-age climates influenced deep-water production in polar latitudes. At the same time, bathyal biofacies, especially ones characterized by Uvigerina and Globocassidulina, extended their bathymetric ranges as much as 2 km deeper.

In response to the Quaternary stagnations and recirculation associated with sapropel deposition in the eastern Mediterranean, most benthic foraminifera changed their bathymetric distributions. Deep-water biofacies (Globobulimina, Articulina) shallowed as deep basins became anoxic; shallower biofacies (miliolids) extended their ranges as recirculation oxygenated the deep water.

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