Phytoliths infer locally dense and heterogeneous paleovegetation at FLK North and surrounding localities during upper Bed I time, Olduvai Gorge, Tanzania

作者：Barboni Doris^*; Ashley Gail M; Dominguez Rodrigo Manuel; Bunn Henry T; Mabulla Audax Z P; Baquedano Enrique

来源：Quaternary Research, 2010, 74(3): 344-354.

DOI：10.1016/j.yqres.2010.09.005

• Silica bodies
• Opal-A
• Paleoenvironment
• Pleistocene
• Hominin
• East Africa

The phytolith content of 10 samples collected immediately under Tuff IF (similar to 1.785 Ma) at FLK N and other surrounding localities (similar to 2 km(2)) provides a direct botanical evidence for woody vegetation in the eastern margin of Olduvai Gorge during uppermost Bed I time. Observation and counting of 143 phytolith types (5 to > 150 mu) reveal dense but heterogeneous woody cover (similar to 40-90%) of unidentified trees and/or shrubs and palms associated to the freshwater springs surrounding FLK N, and more open formation (presumably similar to 25-70% woody cover) in the southeast at localities VEK, HWK W and HWK E. The paleovegetation is best described as groundwater palm forest/woodland or bushland, which current analogue may be found near Lake Manyara in similar hydrogeological context (freshwater springs near saline/alkaline lake). Re-evaluating the published pollen data based on this analogy shows that 70% of the pollen signal at FLK N may be attributed to thicket-woodland, Acacia groundwater woodland, gallery and groundwater forests; while <30% is attributed to swamp herbage and grasslands. Micro-botanical, isotopic, and taphonomical studies of faunal remains converge on the same conclusion that the area surrounding FLK N, which attracted both carnivores and hominins in the early Pleistocene, was densely wooded during uppermost Bed I time.

• 出版日期2010-11