We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Erosion in northwest Tibet from in-situ-produced cosmogenic <sup>10</sup>Be and <sup>26</sup>A1 in bedrock.
- Authors
Pin2 Kong; Chunguang Na; Fink, David; Lin Ding; Feixin Huang
- Abstract
Concentrations of in-situ-produced cosmogenic nuclides 10Be and 26Al in quartz were measured by accelerator mass spectrometry for bedrock basalts and sandstones located in northwest Tibet. The effective exposure ages range between 23 and 134 ka (10Be) and erosion rates between 4.0 and 24 mm ka-1. The erosion rates are significantly higher than those in similarly arid Antarctica and Australia, ranging between 0.1 and 1 mm ka-1, suggesting that precipitation is not the major control of erosion of landforms. Comparison of erosion rates in arid regions with contrasting tectonic activities suggests that tectonic activity plays a more important role in controlling long-term erosion rates. The obtained erosion rates are, however, significantly lower than the denudation rate of 3000-6000 mm ka! beginning at c. 5- 3 Ma in the nearby Godwin Austen (K2) determined by apatite fission-track thermochronology. It appears that the difference in erosion rates within different time intervals is indicative of increased tectonic activity at c. 5-3 Ma in northwest Tibet. We explain the low erosion rates determined in this study as reflecting reduced tectonic activity in the last million years. A model of localized thinning of the mantle beneath northwest Tibet may account for the sudden increased tectonic activity at c. 5-3 Ma and the later decrease.
- Subjects
TIBET (China); SOIL erosion; LANDFORMS; SEDIMENT transport; SANDSTONE; QUARTZ; ACCELERATOR mass spectrometry; METEOROLOGICAL precipitation; PLATE tectonics; ARID regions
- Publication
Earth Surface Processes & Landforms, 2007, Vol 32, Issue 1, p116
- ISSN
0197-9337
- Publication type
Article
- DOI
10.1002/esp.1380