Cosmogenic dating methods Sexdating woman free no credit card
At both localities, the evolutive degree of the associated fossil mammal assemblages allowed a biochronological estimation of the hominid remains: early Pliocene (3–3.5 Ma) at KT 12 and late Miocene (≈7 Ma) at TM 266. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock. Localities investigated in this area include TM 266 and TM 254 (Fig. The Kollé (KL), Kossom Bougoudi (KB), and Koro Toro (KT) fossiliferous areas were specifically studied to calibrate the authigenic Be dating method by direct comparison with biochronological estimations of co-located mammalian assemblages.Fossiliferous localities investigated in these areas were KL, KB 1, and KT 12 (Fig. KT 12 (16°00′N, 18°53′E) is the site of locality, Toros-Menalla, Upper Miocene, Northern Chad).
To apply the radioactive decay equation described above, it is thus essential to know the regional initial authigenic Be ratio.This is unlike most other radiochronological methods (U-Th, Rb-Sr, Sm-Nd, K-Ar, Lu-Hf, Re-Os, etc.) that rely on parent–daughter ratios to determine ages.