Evolution of the Salmon River suture and continental delamination in the Syringa embayment

The geology of west-central Idaho is dominated by the Salmon River suture that formed during dextral-oblique plate motion in the Cretaceous (~130-85 Ma). It is an unusual suture because it (1) juxtaposes Mesozoic island-arc rocks directly against Proterozoic continental rocks; (2) is defined by abrupt changes in Sr/Sr intial ratios, ages, and origins in nearby and stitching plutons; and (3) has an ~90-degree change in trend from NNE in Idaho to W into Washington (Syringa embayment). NE of the embayment, SHRIMP U-Pb dates on detrital zircon show that Cretaceous island arc rocks are intercalated with Proterozoic continental rocks; U-Pb dates on inherited zircon and Sr and Nd isotopic analyses indicate diverse plutonic sources; U-Pb intrusive ages limit events.