| one publication added to basket [14464] | Diatoms in the Zaire deep-sea fan and Pleistocene palaeoclimatic trends in the Angola Basin and west equatorial Africa
Mikkelsen, N. (1984). Diatoms in the Zaire deep-sea fan and Pleistocene palaeoclimatic trends in the Angola Basin and west equatorial Africa. Neth. J. Sea Res. 17(2-4): 280-292
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Abstract |
The marine diatom assemblages remain almost constant during the glacial-interglacial cycles of the Middle and Late Pleistocene. The abundance patterns of diatoms point to a comparatively higher glacial than interglacial productivity. Significantly higher abundances of Thalassionema sp. in cold than in warm core sections indicate a stronger glacial than interglacial productivity. Preservation is notably better in cold than in warm periods. Brackish-water and fresh-water diatoms occur consistently, and the brackish forms totally dominate the assemblages of warm climatic events. This points to predominantly wet interglacial conditions in parts of the drainage area of the Zaire river. Phytoliths and plant cuticles occur in highest abundance in glacial core intervals. Low amounts of plant debris in interglacial core sections are ascribed to intense productivity and immediate decomposition of material in the humid equatorial rainforest. Commonly occurring grass plant cuticles have a burnt image in glacial core sections. This mirrors the glacial reduction of the rain forest in favour of a dry and inflammable savannah vegetation, where intensified glacial trade winds carried the charred plant material into the Angola Basin. |
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