HR: 0800h
AN: T11D-0408    [Abstracts]
TI: Insights into the spatio-temporal evolution of the Taiwanese range from the analysis of the foreland basin.
AU: Simoes, M
EM: simoes@gps.caltech.edu
AF: California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 United States
AU: Simoes, M
EM: simoes@gps.caltech.edu
AF: Ecole Normale Superieure, 24 rue Lhomond, Paris, 75005 France
AU: * Avouac, J
EM: avouac@gps.caltech.edu
AF: California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 United States
AB: The Taiwanese range has resulted from the oblique collision between the Luzon volcanic arc and the Chinese continental margin. Because of this obliquity, the collision started north of the island about 6.5 Myr ago, and has since propagated southward. The young and still ongoing Taiwan orogeny is an ideal place to investigate how the spatio-temporal evolution of the range was recorded in the structure of its adjacent basin. The foreland basin stratigraphy and subsidence history has been extensively documented by well-logs, seismic investigations onshore and offshore Taiwan, as well as studies of the foreland sediments incorporated into the foothills by the westward advancing orogen. We take advantage of this available data to trace the spatio-temporal dynamic evolution of the range and basin. These data can be used to estimate 1) the rate of westward progradation of the orogen over the foreland, and thus also the shortening rate across the range, as well as 2) the rate of southward migration of depocenters which reflects the southward propagation of maturation of the range. We estimate the rate of shortening across the range to 39-44mm/yr and the rate of southward migration to 31 +/- 10/5 mm/yr. We subsequently derive a simple 4-D kinematic modeling of the basin subsidence. This model implies that the range and basin dynamic system has approached a steady geometry very rapidly, in less than 2Myr, most probably because of the high rates of deformation and erosion present in Taiwan. These data places important constraints on the thermo-kinematic and morphologic evolution of the range itself.
DE: 8104 Continental margins: convergent
DE: 8138 Lithospheric flexure
DE: 8169 Sedimentary basin processes
SC: Tectonophysics [T]
MN: Fall Meeting 2005