DEPOSITIONAL ENVIRONMENT AND PROVENANCE OF THE PINK MEMBER OF THE CLARON FORMATION, SOUTHWESTERN UTAH

The Eocene Claron Formation is ubiquitous throughout much of the Colorado Plateau region of southwestern Utah, and has been long interpreted as dominantly lacustrine in origin. We measured stratigraphic sections of the lower Pink Member of the Claron Formation in Casto and Losee canyons located near Panguitch, Utah, determined paleocurrent orientations and depositional environments, and performed detailed clast counts to assess provenance and better constrain the Eocene tectonic activity in this section of the Colorado Plateau. The lower Pink Member of the Claron Formation consists of orange, medium- to coarse-grained, bioturbated, calcium carbonate cemented sandstones with interbedded granule to cobble, imbricated, clast supported conglomerate beds that average 3 m in thickness and commonly incise into underlying beds. Clast compositions include a combination of mudstones, sandstones, quartzites and cherts, with chert clasts becoming less prominent up-section. Paleocurrent analysis of clast imbrication is indicative of flow towards ENE, NE, SSE, and SE. These conglomerates were deposited in a high-energy environment characterized by coarse-grained material (up to 28 cm) that was shed from the west and transported by braided fluvial processes. The lower Pink Member of the Claron Formation was deposited in a high-energy fluvial environment that received sediment from the Sevier highlands to the west; continued transport was ultimately blocked by Laramide structures to the east.