Cosmogenic surface exposure dating Free freaky webcam chatrooms
East of the LGM margin exposure ages from 35 samples show Late Weichselian ages in a range between 20.6 - 11.9 ka.
To test to what extent these dates reflect the onset of deglaciation immediately after cessation of active glacier flow, surface exposure ages are evaluated against independent chronologies of Late Weichselian ice-sheet fluctuations in southwestern Scandinavia.
Data from both cosmogenic nuclides are in overall good agreement with each other confirming continuous exposure of the Gotthard Pass area throughout the Holocene.
Some slightly younger in situ 14C ages compared to the corresponding 10Be ages are interpreted to result from partial surface shielding due to snow cover.
While modelling results revealed a major reorganization of the ice streams over the last 20 ka, cosmogenic nuclide data from glacial erratics were used to reconstruct past terrestrial ice surface elevations.
Alternatively, this pattern of glaciation may reflect a trend of progressively less extensive glaciation in mountain regions that has been observed globally throughout the Pleistocene.
Radiocarbon dating is abundantly used and offers very high precision dates, but we often want to date an event that is either too far in the past, or without the right type of organic matter, to be dated by C.
This is different from techniques (like Ar, or U/Th) that date the formation of a rock itself.
Super high energy particles—mostly protons— are produced by our Sun, supernovae, and probably other extraterrestrial sources.
during phases of glacier readvance, which might have interrupted the general deglaciation trend.