GEOLOGY OF THE JOMAC MINE, WHITE CANYON AREA SAN JUAN COUNTY, UTAH
The Jomac mine workings consist of two adits connected by a crosscut. Sedimentary rocks exposed in the Jomac mine area are of Permian to Late Triassic age and have combined thickness of more than 1,700 feet. An ancient stream channel, from 200 to 400 feet wide and about 4 feet deep, enters the mine area from the southwest, swings abruptly northwest near the mine workings and continues to the northern tip of Jomac Hill. This channel, including depressions that apparentiy were scoured into its floor, was cut into the upper beds of the Moenkopi formation and filied by Chinle and Shinarump sediments. A tributary channel may have joined it from the southeast at a point near the mine workings. Jomac Hill is on the crest of a southwest-plunging fold on the west flank of a larger syncline. The area surrounding the hill is broken by intense faulting, but no faults were noted in the vicinity of the mine. The major fractures in the mine workings strike N. 70 deg to 80 deg E. and dip steeply. Secondary steeply dipping fractures strike N. 40 deg to 60 deg E., and N. 10 deg E. to N. 10 deg W. The fractures are believed to be related to the anticlinal structure rather than to the faults. Most of the uranium is contained in coal in association with jarosite and gypsum in sandstone, conglomerate, or sandy siltstone near the base of the Shinarump conglomerate. Uranium occurs in metazeunerite, a fibrous green secondary mineral, in an unidentified fibrous yellow mineral, and in an unidentified massive yellow mineral. Secondary copper minerals, including malachite, azurite, and chalcanthite, occur locally with the uranium minerals. Principal ore guides at the Jomac mine are channels, scours at the bottom of these channels, coal-bearing sandstone or conglomerate at the base of the Shinarump conglomerate, coal, and jarosite. (auth)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-12-009825
- OSTI ID:
- 4327262
- Journal Information:
- U.S. Geol. Survey Bull., Vol. Vol: 1046-H; Other Information: 3 illus. Orig. Receipt Date: 31-DEC-58
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
AZURITE
CALCIUM SULFATES
CHALCANTHITE
COAL
CONGLOMERATES
COPPER CARBONATES
COPPER COMPOUNDS
COPPER HYDROXIDES
COPPER SULFATES
DECOMPOSITION
DEPOSITS
GEOLOGY
GYPSUM
IRON HYDROXIDES
IRON SULFATES
JAROSITE
MALACHITE
MINERALS
POTASSIUM SULFATES
ROCKS
SAND
SILT
URANIUM MINERALS
ZEUNERITE