Coal resources of Upper Cretaceous Fruitland Formation in the Southern Ute Indian Reservation, southwestern Colorado

Abstract

Coal resources of the Upper Cretaceous Fruitland Formation in the Southern Ute Indian Reservation are estimated to total 16 billion short tons of bituminous coal in beds 2 feet thick or more. The coal-bearing Fruitland Formation underlies about 700 square miles of the Southern Ute Indian Reservation and crops out in a roughly semicircular band around the northern edge of the structural San Juan Basin. The coal beds locally dip more than 10{degree} to the southeast along the northwestern rim of the basin. The estimate of coal resources is based on a study of about 500 geophysical logs, mostly of oil and gas wells. Total coal resources include 15 billion short tons of identified resources, based on data points 3 miles or less apart, and about 1 billion short tons of undiscovered or hypothetical resources, based on data points more than 3 miles apart. In this report, the coal-bearing interval is divided into three overlapping zones: lower, middle, and upper. Coal resources were estimated by aggregate thickness for each zone. Although the coal on the Reservation is of comparatively high rank, coal in the Fruitland is generally characterized by high ash content. Mining on the Reservation has been restricted generallymore » to small underground and strip mines within 200 feet of the surface along the edges of the San Juan Basin.« less