Northeast margin of Tibetan PlateauOrdos blockWeihe grabenDense seismic arrayMoho transition zoneReceiver functionNORTH CHINA CRATONLITHOSPHERIC STRUCTURE BENEATHWESTERN WEIHE GRABENTIBETAN PLATEAUNORTHEASTERN MARGINEXTRUSION TECTONICSASIAN LITHOSPHERESPECTRAL-ELEMENTADJACENT REGIONSMANTLE STRUCTURE