P- and S-Wave Receiver Function Images of Crustal Imbrication beneath the Cheyenne Belt in Southeast Wyoming

• DOI: 10.1785/0120080168
• Publication Date: 2009-06-08T04:13:03Z
• Authors: S. Hansen; K. Dueker
• Keywords: Imbrication; Cheyenne; Receiver function

We extend the receiver function deconvolution methodology of Bostock (2004) to S-wave functions and develop a method source spec- trum estimation constrain crustal structure across Archean-Proterozoic Cheyenne belt suture in southeast Wyoming using data from dense deployment seismic stations. are particularly useful because free- surface reverberations do not contaminated direct Sdp arrivals, image is able validate our P-wave image. P- images teleseismic tomogram find consistent with imbrication Proterozoic lower crust Chey- enne belt. Both P delineate double Moho north belt: Archean imaged at 41-43 km depth deeper velocity step 60-62 depth. South belt, finds dipping ∼7° northwest observed back-azimuth dependent Pms amplitudes. Given lateral continuity Moho, interpreted as imbricated Moho. Modeling re- ceiver amplitudes suggests 6:4-7:4 km=sec shal- 7:4-7:9 speculate that was contemporaneous 1.76 Ga uplift deformation 50 km-wide Palmer Canyon block immediately exposed Laramie Mountains.