Terrestrial cosmogenic nuclide dating
These are giving erosion rates that vary from a few tens of meters to hundreds of meters per million years.
The differences in rates of erosion likely reflect different climate and tectonic settings, but it is usually difficult to resolve which of the two sets of processes dominate.
Long term rates of uplift have been broadly defined using petrological and structural geological methods, which essentially indicate how quickly rock is brought to the surface and/or exhumed.
Recently, global positioning systems have been used to determine short-term (years-decades) rates of surface displacement.
Production rates of cosmogenic nuclides made in situ in terrestrial samples and how they are applied to the interpretation of measured radionuclide concentrations were discussed at a one-day Workshop held 2 October 1993 in Sydney, Australia.
The status of terrestrial in-situ studies using the long-lived radionuclides Be, C, Al, Cl, and Ca and of various modeling and related studies were presented.
Continent: Asia Country: Pakistan, India, Nepal and China State/Province: N/A City/Town: N/A UTM coordinates and datum: none Climate Setting: Tropical Tectonic setting: Continental Collision Margin Type: Process Figure 1.
Details1500 km north-south with an average elevation of ~5000 m above sea level.The Chandra River flowed across this granite, rounded it and producing potholes before finally incising to a lower level several thousand years ago.These straths and others throughout the Himalaya have been dating using terrestrial cosmogenic radionuclides to determine their ages and hence rates of fluvial erosion.Numerous strath terraces have been dated using Be-10 throughout the Himalaya (summarized in Dortch et al., 2011).These are providing good estimates for rates of river erosion.
In particular, the studies are showing that rates of erosion Himalayan rivers range greatly, from as little as 0.02 to 25 mm/year based on strath terraces that date from a few thousand to many hundreds of thousands of years.