Open AccessAncient delta deposits in the Ivie Creek area, Ferron Sandstone member of the Mancos Shale, western San Rafael Swell, east-central Utah
Author(s) -
Thomas C. Chidsey,
Paul B. Anderson
Publication year - 2019
Publication title -
utah geological association publication
Language(s) - English
Resource type - Journals
eISSN - 2693-3438
pISSN - 0375-8176
DOI - 10.31711/geosites.v1i1.74
Subject(s) - geology , outcrop , fluvial , facies , oil shale , swell , cretaceous , paleontology , delta , anticline , geomorphology , oceanography , tectonics , structural basin , engineering , aerospace engineering
In contrast to the beautiful array of colorful layers and spectacular cliffs of the Triassic and Jurassic (251 to 148 million years ago [Ma]) sections in the San Rafael Swell of east-central Utah, most of the Upper Cretaceous (96 to 86 Ma) Mancos Shale produces a drab, barren landscape. However, lying within the Mancos, the Ferron Sandstone, is the most studied unit in the San Rafael Swell. The Ferron has world-class outcrops of rock layers deposited near the shorelines of a sinking, fluvial- (stream) dominated delta system. Along the west flank of the San Rafael Swell, the 80-mile-long (130 km) Ferron outcrop belt of cliffs and side canyons (e.g., the Coal Cliffs, Molen Reef, and Limestone Cliffs [not actually limestone, just misnamed]) provides a three-dimensional view of vertical and lateral changes in the Ferron’s rock layers (facies and sequence stratigraphy), and, as such, is an excellent model for fluvial-deltaic oil and gas reservoirs worldwide (e.g., Chidsey and others, 2004).