Suppe seminar at UMD next Wednesday
A special seminar coming up at the University of Maryland, College Park:
Wednesday December 9, 11:00am-12noon
CHEM 0115 (next to the Chemistry office)
John Suppe, Department of Geosciences, National Taiwan University
"Deep and shallow structure of the Taiwan arc-continent collision"
Abstract: The on-going oblique arc-continent collision in Taiwan between the Luzon arc and the Eurasian continental margin provides a classic spatial view of the temporal evolution of the collision. In addition Taiwan is a well-known site of critical-taper wedge mechanics and erosional forcing of deformation, leading to a mountain belt that is approximately in topographic steady state, with erosion balancing the compressive flux. This classic picture, based largely on surface and upper-crustal data, is now being illuminated at lower crustal and upper mantle levels with highresolution local seismic tomography and earthquake locations. These new data document in 3D that the deep structure is remarkably independent of the shallow thinned-skinned mountain belt. Here we show that the lower crust and upper mantle of the Eurasian plate undergoes a transition from normal subduction and accretionarywedge tectonics south of Taiwan to a strongly localized progressively bent geometry with a vertical to overturned plate interface. The lower crust and Moho of the Eurasian plate is vertical to overturned to depths of 70-80 km under central and northern Taiwan. In this region the deep plate shortening is accomplished by folding of both the Eurasian and Philippine-Sea lower lithospheres without an active subduction zone, whereas the crust of both plates above the main detachment is mechanically and kinematically separated from this deep shortening.
I'll be there, for sure!
Wednesday December 9, 11:00am-12noon
CHEM 0115 (next to the Chemistry office)
John Suppe, Department of Geosciences, National Taiwan University
"Deep and shallow structure of the Taiwan arc-continent collision"
Abstract: The on-going oblique arc-continent collision in Taiwan between the Luzon arc and the Eurasian continental margin provides a classic spatial view of the temporal evolution of the collision. In addition Taiwan is a well-known site of critical-taper wedge mechanics and erosional forcing of deformation, leading to a mountain belt that is approximately in topographic steady state, with erosion balancing the compressive flux. This classic picture, based largely on surface and upper-crustal data, is now being illuminated at lower crustal and upper mantle levels with highresolution local seismic tomography and earthquake locations. These new data document in 3D that the deep structure is remarkably independent of the shallow thinned-skinned mountain belt. Here we show that the lower crust and upper mantle of the Eurasian plate undergoes a transition from normal subduction and accretionarywedge tectonics south of Taiwan to a strongly localized progressively bent geometry with a vertical to overturned plate interface. The lower crust and Moho of the Eurasian plate is vertical to overturned to depths of 70-80 km under central and northern Taiwan. In this region the deep plate shortening is accomplished by folding of both the Eurasian and Philippine-Sea lower lithospheres without an active subduction zone, whereas the crust of both plates above the main detachment is mechanically and kinematically separated from this deep shortening.
I'll be there, for sure!
Labels: maryland, meetings, plate tectonics, structure, taiwan
