Carmel Formation of the Zion Park region, southwestern Utah; a review

Abstract

The name Carmel Formation was first applied to rocks of Jurassic age in the San Rafael Swell of east-central Utah, although the type locality is in the Zioii Park region of southwestern Utah. Subsequently, the Carmel Formation of the Zion Park region was modified as the use of other established names was extended and new names, such as the Winsor Formation, were introduced. As presently defined, the Carmel Formation of the Zion Park region includes all Jurassicstrata above the Navajo Sandstone. Because this sequence contains beds previously assigned to the Winsor Formation, the Winsor is reduced in rank to a member of the Carmel Formation. INTRODUCTION The accepted unit composition of the Carmel Formation (Jurassic) at the type locality in southwestern Utah has undergone several changes. These changes have also involved the Winsor Formation, a Jurassic rock sequence named by Gregory (1948) and associated with the Carmel Formation in southwestern Utah. Type localities for the Carmel and Winsor Formations are near Mount Carmel, about 10 miles east of Zion Park, Utah (fig. 1). WThile mapping these units near Mount Carmel, the author recognized the need for a published summary of the nomenclature for these rocks, especially a chronological review of changes involving components of the Carmel Formation in the Zion Park region. The purpose of this report is to present such a summary. Boundaries of the Zion Park region of this report (fig. 1) conform to those delineated by Gregory (1950a, pi. 2) except that the part in Arizona is excluded because it contains no rocks assigned to the Carmel Formation.