Abstract

The Golconda allochthon in the southern Toiyabe Range, Nevada, is composed of several thrust slices of rocks that belong to three age categories: early Paleozoic, Early Triassic, and late Paleozoic. These slices were stacked mainly during the Sonoma orogeny that occurred between Permian and late Early Triassic time. The late Paleozoic rocks, composing the bulk of the allochthon, range in age between Mississippian and Late Permian and contain four lithotypes that occur in the following structural order above the Golconda thrust: terrigenous, hemipelagic, volcanogenic, and pelagic.

The upper Paleozoic rocks were deformed several times during their eastward emplacement onto the North American continental margin. The deformation involved isoclinal folding and thrusting of these rocks into slices. The slices were openly and gently folded during emplacement, and sporadic mesoscopic folds were formed along their-boundaries. Post-thrust movements along slice boundaries formed kink bands and related folds in slate and chert interbeds. The kinks were later deformed when the Golconda thrust was reactivated. Further contraction, during the Sonoma orogeny or possibly later, was accommodated by imbrication of slices of Early Triassic and their unconformably underlying lower Paleozoic rocks.

First Page Preview

First page PDF preview
You do not currently have access to this article.