2024-03-29T02:14:17Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/926552018-07-18T08:12:55Zcom_10261_82com_10261_8col_10261_335
http://hdl.handle.net/10261/92655
10.1016/j.gr.2012.07.019
226540
Amount of Asian lithospheric mantle subducted during the India/Asia collision
Elsevier
2013
artículo
Replumaz, A.
Guillot, S.
Villaseñor, Antonio
rp07244
Negredo, Ana M.
Budget of continental subduction
Amount of convergence
India–Asia collision
Tibet
Asian continental slab
2013
Body wave seismic tomography is a successful technique for mapping lithospheric material sinking into the mantle. Focusing on the India/Asia collision zone, we postulate the existence of several Asian continental slabs, based on seismic global tomography. We observe a lower mantle positive anomaly between 1100 and 900 km depths, that we interpret as the signature of a past subduction process of Asian lithosphere, based on the anomaly position relative to positive anomalies related to Indian continental slab. We propose that this anomaly provides evidence for south dipping subduction of North Tibet lithospheric mantle, occurring along 3000 km parallel to the Southern Asian margin, and beginning soon after the 45 Ma break-off that detached the Tethys oceanic slab from the Indian continent. We estimate the maximum length of the slab related to the anomaly to be 400 km. Adding 200 km of presently Asian subducting slab beneath Central Tibet, the amount of Asian lithospheric mantle absorbed by continental subduction during the collision is at most 600 km. Using global seismic tomography to resolve the geometry of Asian continent at the onset of collision, we estimate that the convergence absorbed by Asia during the indentation process is ~ 1300 km. We conclude that Asian continental subduction could accommodate at most 45% of the Asian convergence. The rest of the convergence could have been accommodated by a combination of extrusion and shallow subduction/underthrusting processes. Continental subduction is therefore a major lithospheric process involved in intraplate tectonics of a supercontinent like Eurasia.
Gondwana Research
2013
24
936
945