In the Koro Toro fossiliferous area, KT 12 locality (16°00′N, 18°53′E) was the site of discovery of (Toumaï).
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.
One that I am very excited about is using cosmogenic nuclide depth profiles to estimate erosion rates beneath glaciers and ice sheets.
Other projects include dating the retreat of the Vashon Ice Sheet from Puget Sound through the San Juan Islands and the timing and rate of latest-Pleistocene retreat of glaciers in the Convict Creek drainage in the Sierra Nevada of California.
Some projects applying this methodology are: (i) Developing nuclide-specific altitude-latitude scaling schemes, by combining model neutron and proton spectra with excitation functions for different cosmogenic nuclides.
(ii) Investigating boundary effects for neutron-capture and high-energy reactions.
It also serves as a repository for data generated by the group, descriptions of our lab procedures, technical information and calculation methods.
Zach Ploskey Ph D student I am broadly interested in geomorphology, glacial geology and the use ofcosmogenic nuclides to understand landscape evolution during the Quaternary.A chance encounter with baffling He-3/He-4 ratios in the late 1980s led me to cosmic ray produced nuclides and their use in geomorphology and exposure dating. With students and collaborators, I am working on projects in Antarctica, some aimed at dating the last glaciation, others concerned with the long-term history of the ice sheet.