Open AccessAerial Gamma Ray and Magnetic Survey Raton Basin Project. Final Report Vol. 2
Author(s) -
Not Given Author
Publication year - 1979
Language(s) - English
Resource type - Reports
DOI - 10.2172/1088279
Subject(s) - quadrangle , butte , geology , structural basin , archaeology , hopi , igneous rock , group (periodic table) , uranium , plateau (mathematics) , uranium ore , geomorphology , geochemistry , geography , mathematical analysis , chemistry , materials science , mathematics , organic chemistry , metallurgy
The Flagstaff quadrangle in northern Arizona lies at the southwestern edge of the Colorado Plateau. Portions of the Black Mesa Basin and Mogollon Rim lie within the quadrangle. Mesozoic rocks cover 90% of the surface of the Black Mesa Basin, but Paleozoic rocks dominate the Mogollon Rim. Cenozoic instrusive and extrusive rocks of the San Francisco Volcanic Field and the Hopi Buttes are superimposed on the older sedimentary sequence. Magnetic data apparently show contributions from both deep and shallow sources. The San Francisco Volcanic Field is relatively well defined, but deeper-lying structural boundaries are largely masked by the younger igneous rocks in the area. The Flagstaff quadrangle has been relatively unproductive in terms of uranium mining. Some claims are present in the Black Mesa Basin, primarily in Triassic rocks. A total of 195 groups of sample responses in the uranium window qualify as anomalies as defined in Volume I. These anomalies primarily form two distinct groups, though others are scattered throughout the quadrangle. One group is associated with igneous rocks in the northern Hopi Buttes area, and the other, a larger and more indistinct group, is primarily associated with the Shinarump Member of the Triassic Chinle Formation in the northern Painted Desert area. None are directly associated with the locations of known claims