Lothagam-Upper Nawata Mb, Kenia


Fundort: Lothagam-Upper Nawata Mb, Kenia, , Kenia
Taxon: Parapapio lothagamensis aus der Familie Cercopithecidae
Fossilien und Beschreibung der Fundstelle:
Macrofossils,mesofossils, K-Ar dating constrains the Upper Nawata Member to 6.54 +/- 0.04 Ma (Marker Tuff) and 4.22 +/- 0.03 Ma (pumice clasts from 35 m above the top of the Upper Nawata Purple Marker). Thus, top of the Upper Nawata is older than 4.2 Ma, and is estimated to be 5.0 Ma. , The Upper Nawata is characterized by thick, multistoried sandstone bodies, with subsidiary mudstones, and by a paucity of altered distal tephra. The type section consists of some 75% sandstones, 21% mudstones, and 4% altered tephra. The basal unit of the member is a tephra complex termed the Marker Tuff. This complex consists of a thin-bedded, relatively homogeneous lower interval (interpreted as airfall tuff), overlain by a massive, poorly sorted sandy tuff. Sandstones of the upper Nawata are typically characterized by well-developed epsilon cross-stratification and trough cross-beds in the coarser units, grading into small-scale troughs and ripple marks in the overlying finer intervals, with abrupt transitions back to coarser sands. Mudstones are subordinate, but where present they show characteristics of paleosol development. (ref # 8636 p. 22-23).
Geschätztes Alter
der Fundstelle:
zwischen 3,6 und 7,246 Millionen Jahre aus der Nawata or Nachukui Formation in Kenia
Geologie, Sratigraphie Messinian, Zanclean / Messinian / Nawata or Nachukui
Koordinaten: 2° 53 ' 60 '' N, 36° 2 ' 59 '' O

Literatur

M. G. Leakey, J. M. Harris 2003, Lothagam: the dawn of humanity in eastern Africa. Lothagam: the dawn of humanity in eastern Africa. , p. 678

Systematik