Abstract
The Hermosa formation, exposed in the San Juan Canyon where it transects the Monument upwarp in southeastern Utah, contains several biostromal layers, one of which changes laterally into small bioherms with typical reef-limestone breccia making up the greater part of the deposit. A bioherm excellently exposed in the San Juan Canyon walls was examined just above river level in Sec. 4, T. 42 S., R. 18 E., between Mendenhall loop and Honaker trail. At least eight bioherms have been breached by the San Juan River, several of which are exposed on only one canyon wall. The reef limestones are present through approximately two-thirds of the Hermosa thickness below the Hermosa-Rico gradational contact, and the fossils suggest that the bioherms are Des Moines in age. Regionally, the biohermal trends may be controlled by a shelf related to the Paradox-Salt Valley basin in southeastern Utah and southwestern Colorado. Valid predictions of possible distribution of these reefing limestones must be based on further surface examination, subsurface analysis, and an appraisal of regional controls exerted by the Paradox evaporite basin in relation to the Colorado Mountain (Uncompahgre) highlands.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
