Coolwater culmination: Sensitive high-resolution ion microprobe (SHRIMP) U-Pb and isotopic evidence for continental delamination in the Syringa Embayment, Salmon River suture, Idaho

摘要: [1] During dextral oblique translation along Laurentia in western Idaho, the Blue Mountains superterrane underwent clockwise rotation and impinged into Syringa embayment at northern end of Salmon River suture. Along suture, is juxtaposed directly against Laurentia, making this central Cordilleran accretionary-margin segment unusually attenuated. In embayment, limited orthogonal contraction produced a crustal wedge oceanic rocks that delaminated Laurentian crust. The exposed through crust Coolwater culmination as documented by mapping sensitive high-resolution ion microprobe U-Pb, Sri, ɛNd data for gneisses lie inboard predominant country rock Mesoproterozoic paragneiss overlying basement. An Neoproterozoic (or younger) belt establishes form miogeocline relict Rodinia rifting. underlying Cretaceous was derived from arc terranes suture-zone orogenic welt but also Laurentia. an 86-Ma orthogneiss intruded it formed were inserted margin between 98 73 Ma, splitting supracrustal their Crustal thickening, melting intrusion within wedge, folding to continued until 61 Ma. restraining bend transpressional Clockwise impinging overthrusting are predicted collision embayment.