OF-99-12 Evaluation of Mineral and Mineral Fuel Potential of SW Moffat County State Mineral Lands Administered by the Colorado State Land Board

Includes a general summary of the geology and mineral and mineral fuel potential of southwest Moffat County along with topographic and geologic maps of tract locations. The main body of the report is an evaluation of the resource potential for oil and gas, coal, metallic minerals, and industrial minerals for individual tracts. Digital ZIP/PDF download. OF-99-12D

Four general categories of resources are included in this inventory:

• oil and gas
• coal
• metallic minerals
• industrial minerals and construction materials

Each individual tract evaluation includes:

• A bar graph which ranks each tract’s resource potential for each of the four mineral categories. An explanation of the categories may be found at the end of this introduction
• Tract identifier number, county name, and county location map
• Tract location on a 7-1/2-minute United States Geologic Survey topographic map
• Tract location on a United States Geologic Survey surface outcrop map
• Location as to section, township, and range and approximate acreage
• Overview of tract geology
• Specific assessment of the resource potential for the four resource categories
• References used in assessing tract potential

From the Introduction:

Moffat County is situated in the extreme northwest corner of the state and includes elements of three major Rocky Mountain Foreland structural features: Sand Wash Basin, Axial Basin Uplift, and Piceance Basin. Mineral resources include uranium, vanadium, and minor molybdenum, silver, and gold. There were also prospects of zinc, lead, copper, manganese, and iron. Industrial minerals include sand and gravel, clay, crushed aggregate and building stone, gypsum, coal, coal bed methane (minor), and oil and gas. Their locations are detailed below.

For the purpose of resource evaluation, Moffat County was divided into four quadrants: NE, SE, NW, and SW. Uranium prospects and/or mines occur in all four quadrants of Moffat County but are vastly more numerous in the SE Quadrant. Gold prospects and/or mines are found in all quadrants of Moffat County and exploited the metal primarily from placer and, in some instances, paleoplacer sources. The most productive gold deposits in Moffat County are situated in its NE Quadrant. There are two oxidized zinc-lead prospects located in the SW Quadrant within the boundaries of Dinosaur National Monument. All of the copper prospects located in Moffat County occur in its SW Quadrant. Three manganese prospects are located in the SW Quadrant. Blue-black hematite mixed with limonite and ocher occur in the SW Quadrant. Sand and gravel deposits occur in every quadrant of Moffat County. Gypsum resources are located in both the NW and SW Quadrants. Coal mines and prospects dominate the natural resource occurrences in the SE Quadrant, but are also present in the SW Quadrant and to a much lesser extent in the NE Quadrant. Oil and gas production in Moffat County occurs within two of the three major Rocky Mountain Foreland structural features that are present within the county: Sand Wash Basin with its associated Cherokee Arch and the Axial Uplift. The small portion of the Piceance Basin that is present in the county is not productive.