Crust and Upper-mantle Structure in the Western North China Craton from Receiver Functions
Tuesday, 16 December 2014
North China Craton (NCC) is separated by the Trans-North China Orogen into two parts: the Eastern NCC and the Western NCC. It has been proposed that the Western NCC has remained stable since the Precambrian. Here receiver function (RF) analysis is used to image the crustal structures along an N-S profile (31N-43N) across the Qinling Orogen from the south, through Ordos Block and Yinshan Orogen to the north. The profile consists of 36 portable broadband stations which were deployed by Peking University during June 2012 to June 2014 and 12 permanent seismic stations of CEA. We selected teleseismic P waveforms from events with magnitudes Mw>5.0 and within the epicentral distances of 35-90 degrees and used the iterative time domain deconvolution method to obtain the RFs. Crustal thickness and the average Poison’s ratio are obtained by the use of H-k method while the 410 and 660 discontinuity depths are calculated by using common conversion point stacking method from the RF data. The fine structures from this receiver function study should help us to better understand the nature and evolution of the Western NCC.