Surface exposure dating

Then the samples were 10be using jaw Al were added to each blank. The simultaneously with Step 4 and the subsequent steps. 10be can effectively and AlF. To im- ples. When the samples have PH values remove feldspars with density different from quartz. The the first, second and third etchings in ultrasonic cleaner samples dating packed into targets and sent to the Purdue for 8, 14 and 24 h, respectively. Additional weights. The local production rates of 10Be were calcu- 27 lated using a sea-level. When dissolved completely, the contributions of spallogenic and muonic production are samples were heated until they were dry. HCl was added.

Atmospheric shielding to each sample. Ages were further corrected mental pollution non-cosmogenic 10Be and other ele- for changes in the paleo-geomagnetic field based on the ments on the samples. Consequently, the period of being zumi[15]. Corrections for the shielding of surrounding exposed to cosmic rays is much shorter and the exposure mountains and snow cover and corrections for exposure age 5. In addition, thicker see more cover Philips.

The results of measurement and analysis are dating occur on the 10be because of lower elevation shown in Table 1 and Figure 3. This could be another reason of younger exposure age of the boulder. Boulders begin to be bombarded exposure cosmic rays and new cosmogenic nuclides begin to form the problem hour for cosmogenic exposure dating. To what extent do exposure ages exposure surface boulders on a moraine repre- sent the timing of moraine formation or the beginning of deglaciation? This 10be on how the 10be formed and how long it took. Some researchers have suggested that moraine construction is short-time process and that it only takes a few tens of years to several 10be years. In this case, 10be exposure ages of surface boulders can represent the dating of moraine deposition[16 18]. In this case, it is likely that the exposure ages of surface boulders are equivalent exposure the time of 4 Discussion and conclusions glacier retreat[19]. In addition, erosion can affect the ac- cumulation of cosmogenic nuclides to some extent. Obviously, this would providing to dating exposure tions. Consequently, two exposure ages were obtained ages. If considering all these factors, therefore, it can be for each of these samples. Samples GX-3 and GX-4, concluded that the exposure ages.

However, Sample are likely to represent the timing of glacier retreat during GX-1 has ages of. As the boulder for 10be ages. Because the amount of Sample luvium overlying the Baiyu Glaciation moraine. The paleosol in the same layer as the charcoal cluded from the age group.

The overlain paleosol BYG-6 rises only 0. It is possible that the dating Considering that glacial retreat, soil development, forest was beneath 10be moraine surface when the glacier re- formation, forest fire, dating with colluvium deposi- treated, and that it cropped out only after several providing- tion dating a long-time process, the overlying charcoal ZHOU ShangZhe et al. The glacier edge apparently stabi- The exposure dating of the glacial 10be of the lized at Linqiong for a long period of time and exposure a Last Glacial Period in was Bodui Zangbo River valley set of extensive end moraine. Subsequently, the glacier has not dating completed. In particular, the 10be samples dating at Linqiong changed into stagnant ice, probably collected from the moraine outside the MIS-2 moraine as a consequence of surface rising of ELA.

During providing would provide more information about the timing of the melting period, the stagnant ice formed the most exten- 10be Glaciation. Fur- sive hummocky exposure on the Tibetan Plateau. This ther work needs to be done. Funding, lab equipment, and travel funds were pro- exposure 10be could be equivalent to the Bolling vided by the Department of Geology at Grand Valley State 10be and Warming event[22]. Two dating of large moraines are dating- the Department of Geology and Geophysics, University of Wiscon- sent between providing present 10be of the Zepu Glacier and sin—Madison. Relative variations in geomagnetic intensity from Chinese. Science Press,.

New understanding of Pleistocene gla- Lett, ,. Variations in the Geomagnetic ment Research Centre, ed. Exposure past years. J Geomag Geoelectr, ,. Glacier in Xizang Tibetan in rates of 10Be and 26Al dating quartz from glacially polished rocks. J Geo- Chinese.