Search USGS⌕ Search

Geology topics

E. J. McKay

Publications and source records attributed to E. J. McKay.

53 records · Page 3Linked to original sources
USGS1954

Geology of the Uravan quadrangle, Montrose county, Colorado

The Uravan quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of the southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to the related to certain sedimentary structures in sandstones of favorable composition.

Colorado↗
USGS1953

Geology of carnotite-bearing sandstone in the Uravan and Gateway districts, Montrose and Mesa counties, Colorado, and Grand County, Utah

Most of the caraotite deposits in the Uravan and Gateway mining districts ate in the persistent upper sandstone stratum of the Salt Wash sandstone member of the Morrison formation, Areas In which this stratum is predominantly lenticular have been delimited from areas in which this stratum is predominantly nonlenticularar. Ground most favorable for carnotite deposits is in areas of lenticular sandstone where the stratum is underlain by green-gray altered mudstone. Ore is localized in scour-and-fill bedded sandstones within favorable areas of lenticular sandstone. Regional control of the movement of ore-bearing solutions in the persistent ore-bearing sandstone stratum is indicated by; 1. A concave arcuate belt of partly altered mudstone transitional between areas of unaltered mudstone to the west and areas of altered mudstone to the east; 2. An increase in size, grade, and number of ore deposits from areas of partly altered to altered mudstone.

Colorado;Utah↗
USGS1953

Geology of the Atkinson Creek quadrangle, Montrose county, Colorado

The Atkinson Creek quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of the quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that rangein age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confines to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Bath". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstone of favorable composition.

Colorado↗
USGS1953

Geology of the Red Canyon quadrangle, Montrose county, Colorado

The Red Canyon quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium, minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Colorado↗