Abstract

Strong stratigraphic and structural similarities exist between metamorphic rocks of the Saddlebag Lake pendant, eastern Sierra Nevada, California, and rocks of the Antler and Sonoma orogenic belts in west-central Nevada. These similarities indicate that the Roberts Mountains and Golconda allochthons can be traced to the eastern edge of the Sierra Nevada batholith in California. Newly recognized thrust faults that imbricate the Antler and Sonoma rocks and younger metamorphic rocks are of Late Triassic age and are cut by a 219 Ma pluton. These thrusts apparently were active during a major episode of Late Triassic arc volcanism, and they constrain the age of the Golconda thrust as pre–latest Triassic. The continuation of the Antler and Sonoma orogenic belts to the Saddlebag Lake pendant means that large strike-slip displacements cannot have occurred on northwest-trending faults along the eastern edge of the Sierra Nevada. However, a large structural break may terminate the Antler and Sonoma belts at or near the western edge of the Saddlebag Lake pendant.

You do not currently have access to this article.