Erosion-rate determination from foreland basin geometry
نویسنده
چکیده
The geometry of foreland basins is controlled by a dynamic balance between thrust-belt migration, fl exural subsidence, and fl uvial deposition. To improve our ability to quantify the relationships between tectonics, climate, and foreland basin geometry, I developed analytic solutions for basin topography and stratigraphy using a classic two-dimensional mathematical model of foreland basin evolution. Model predictions for basin topography are successfully tested against observed profi les along a humid-to-arid climatic gradient in the central Andes. Using published estimates for the thrust-belt migration rate, fl exural parameter, and thrustfront basin depth in this region, I show that basin topographic profi les can be used to estimate the upstream erosion rate at any point along a foreland basin. Basin-averaged erosion rates estimated in this way vary from 0.025 to 0.045 mm/yr in the central Andes, increasing from semiarid to humid climates.
منابع مشابه
The Ganges basin geometry records a pre-15 Ma isostatic rebound of Himalaya
7 The Tertiary continental strata of the Himalayan foreland basin are subdivided in two 8 groups, but the meaning of this subdivision was previously unclear. From the analysis of drill9 holes, seismic lines, dated sections, field outcrops and balanced cross-sections, we find that the 10 southward migration rate of the deposition pinch-out of the younger group is 19 ± 5 mm/yr and 11 equals the H...
متن کاملNeogene to Quaternary broken foreland formation and sedimentation dynamics in the Andes of NW Argentina (25°S)
[1] The northwest Argentine Andes constitute a premier natural laboratory to assess the complex interactions between isolated uplifts, orographic precipitation gradients, and related erosion and sedimentation patterns. Here we present new stratigraphic observations and age information from intermontane basin sediments to elucidate the Neogene to Quaternary shortening history and associated sedi...
متن کاملThrusting and gravel progradation in foreland basins: A test of post-thrusting gravel dispersal
The use of gravels as syntectonic indicators of thrusting has recently been questioned by foreland-basin models that assign gravels to a post-thrusting interval of progradation, except in very proximal areas. On the basis of precise temporal control provided by magnetostratigraphically dated sections, the history of gravel progradation after a major thrusting and uplift event in the northwester...
متن کاملMetamorphism and exhumation of the NW Himalaya constrained by U–Th–Pb analyses of detrital monazite grains from early foreland basin sediments
Single detrital monazite grains from the Dharamsala and Lower Siwalik Formations (early to mid-Miocene continental foreland basin sediments in NW India) have been dated by two techniques; isotope dilution thermal ionization multicollector mass spectrometry (ID-TIMS) and laser ablation plasma ionization multicollector mass spectrometry (LA-PIMMS). The results give U–Th–Pb isotopic ages of c. 400...
متن کاملModeling the evolution of the Guadalquivir foreland basin (southern Spain)
[1] Previous quantitative studies dealing with the origin of foreland basins have focused primarily either on the rheological basis of the lithosphere mechanical response or on the relationship between orogenic loading and sediment geometry. To link the evolution of the Guadalquivir foreland basin (South Iberia) with the thermomechanical stratification of the Iberian lithosphere, we combine qua...
متن کامل