Mathematics – Logic
Scientific paper
Jan 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007e%26psl.253..402v&link_type=abstract
Earth and Planetary Science Letters, Volume 253, Issue 3-4, p. 402-414.
Mathematics
Logic
5
Scientific paper
Escarpments are prominent morphological features along high-elevation passive margins. Recent studies integrating geomorphology, thermochronology, and cosmogenic nuclide-based denudation rate estimates suggest a rapid phase of denudation immediately after the earliest stages of seafloor spreading, and subsequent slow denudation rates since. To constrain the geomorphic evolution of passive margins, we have examined the development of the Sri Lankan escarpment. Cosmogenic nuclide data on river sediment along a north south transect across the southern escarpment reveal that the landscape is eroding ten times more rapidly in the escarpment zone (26 to 71 mm kyr- 1) than in the high-elevation plateau above it and in the lowland plain beneath it (2.6 to 6.2 mm kyr- 1). Unlike these low denudation rate areas, the escarpment denudation is strongly and linearly hill slope-dependent. This shows that denudation and retreat are tightly interlinked within the escarpment, which suggests that the escarpment is evolving by rift-parallel retreat, rather than by escarpment downwearing. Supporting evidence is provided by the morphology of rivers draining the escarpment zone. These have steep bedrock channels which show sharp and prominent knickpoints along their longitudinal profiles. It appears that fluvial processes are driving escarpment retreat, as rivers migrate headwards were they incise into the high-elevation plateau. However, the average catchment-wide denudation rates of the escarpment zone are low compared to the denudation rates that are estimated for constant escarpment retreat since rifting. In common with other escarpments worldwide, causes for this slow down can be tectonic change related to flexural bending of the lithosphere, climate change that would vary the degree of precipitation focused into the escarpment, or the decrease in the contributing catchment area, which would reduce the stream power available for fluvial erosion.
Hewawasam T.
Kubik Peter W.
Vanacker V.
von Blanckenburg Friedhelm
No associations
LandOfFree
Constraining landscape development of the Sri Lankan escarpment with cosmogenic nuclides in river sediment does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Constraining landscape development of the Sri Lankan escarpment with cosmogenic nuclides in river sediment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraining landscape development of the Sri Lankan escarpment with cosmogenic nuclides in river sediment will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1253969