Terrestrial cosmogenic nuclide dating

26 Dec

Single or multiple nuclides can be measured in a single rock surface to obtain erosion rates on boulder and bedrock surfaces, fluvial incision rates, denudation rates of individual landforms or entire drainage basins, burial histories of rock surfaces and sediment, scarp retreat, fault slip rates, paleoseismology, and paleoaltimetry.

terrestrial cosmogenic nuclide dating-87

A remnant of ancient lake shoreline deposits that once extended across the Hanaupah Canyon fan constrains the timing and extent of the last deep cycle of Pleistocene Lake Manly.These fans are characterized by a relatively smooth, densely packed desert pavement formed by well-varnished (blackened) clasts.These surfaces have been mapped as the Q2 gravel by previous workers and as unit Qai (intermediate age) by us.The exposure ages of the Indus Valley moraines are the oldest observed to date throughout the Himalayan orogen.We observe a pattern of progressively more restricted glaciation during the last five glacial cycles, likely indicating a progressive reduction in the moisture supply necessary to sustain glaciation.The different physical and chemical properties of the six most widely used nuclides: years.The terrestrial in situ cosmogenic nuclide method is beginning to revolutionize the manner in which we study landscape evolution.The lacustrine delta complex yields a 36Cl depth-profile date of 130 ka, which is consistent with deposition during a highstand of Lake Manly at the end of MIS 6.These deposits are presently at an altitude of about 30 meters above sea level (asl), which relates to a lake with a maximum depth of about 115 meters.A possible explanation is that uplift of Himalayan ranges to the south and/or of the Karakoram Mountains to the west of the region may have effectively blocked moisture supply by the south Asian summer monsoon and mid-latitude westerlies, respectively. 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.