Mid-Pleistocene environmental change in tropical Africa began as early as 1.05 Ma

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doi: 10.1130/0091-7613(2001)029<0195:MPECIT>2.0.CO;2
Author(s): Dupont, L. M.; Donner, B.; Schneider, R.; Wefer, G.
Author Affiliation(s): Primary:
Geosciences Bremen, Bremen, Federal Republic of Germany
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 29(3), p.195-198. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. With GSA Data Repository Item 2001021. 28 refs.; illus.
Summary: Palynological records from the Congo fan reveal environmental change in equatorial Africa occurring 1.05 Ma ago, 100 k.y. before the mid-Pleistocene climatic shift at 0.9 Ma. Prior to 1.05 Ma, a glacial-interglacial rhythm is not obvious in the African vegetation variation. Afterwards, Podocarpus spread in the mountains of central Africa mainly during glacials and Congo River discharge decreased. The sequence of vegetation variation associated with the mid-Pleistocene glacials and interglacials differed from that observed during the late Pleistocene. Between 0.9 and 0.6 Ma, interglacials were characterized by warm dry conditions and glacials were characterized by cool humid conditions, while during the past 0.2 Ma glacials were cold and dry and interglacials warm and humid. Our data indicate that before the Northern Hemisphere ice caps dramatically increased in size (0.9-0.6 Ma), low-latitude climate forcing and response in the tropics played an important role in the initiation of 100 k.y. ice-age cycles. During the mid to late Pleistocene, however, the climate conditions in the tropics were increasingly influenced by the glacial-interglacial variations of continental ice sheets.
Year of Publication: 2001
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Africa; Biostratigraphy; Cenozoic; Central Africa; Climate change; Climate effects; Congo River; Dinoflagellata; Feedback; Foraminifera; Forests; Glacial environment; Glacial extent; Ice sheets; Interglacial environment; Invertebrata; Leg 175; Magnetic susceptibility; Marine sediments; Microfossils; Middle Pleistocene; Miospores; Monsoons; ODP Site 1075; ODP Site 1077; Ocean Drilling Program; Paleoclimatology; Paleoecology; Paleomagnetism; Palynomorphs; Pleistocene; Podocarpus; Pollen; Protista; Quaternary; Sediments; Terrestrial environment; Tropical environment; Vegetation
Coordinates: S044707 S044707 E0100430 E0100430
S051048 S051048 E0102611 E0102611
Record ID: 2001021640
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