Plio-pleistocene lacustrine stromatolites from lake Turkana, Kenya: Morphology, stratigraphy and stable isotopes
1982; Elsevier BV; Volume: 32; Issue: 1-2 Linguagem: Inglês
10.1016/0037-0738(82)90011-2
ISSN1879-0968
AutoresPaul I. Abell, Stanley M. Awramik, Robert H. Osborne, Sterling A. Tomellini,
Tópico(s)Isotope Analysis in Ecology
ResumoA sequence of fossil stromatolites from Lake Turkana in Kenya was examined for δ18O and δ13C content. These stromatolites, ranging in age from Holocene (∼10,000 yrsB.P.) to Middle Pliocene (≈3 m.y.) showed a variety of growth forms from oncolitic, columnar layered to bulbous heads. The stromatolites used in our study contain filamentous blue-green algae of one morphological type and rare coccoids; thus the stromatolites are considered biogenic. The stable isotope ratios for oxygen and carbon indicate changing climatic conditions, ranging from a cool, wet climate prior to ca. 1.9 m.y. to much drier, warmer conditions around 1.4 m.y., followed in turn by a somewhat cooler and wetter climate at the end of the Pleistocene.
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