Geologic and geochemical study of tin-bearing rhyolites in the Broken Ridge area, southern Wah Wah Mountains, Utah

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6875122

Duttweiler, K A; Griffitts, W R

This study was undertaken to document the geologic, petrologic, and geochemical relationships of the tin-bearing rhyolitic lava flows and domes of the 12-m.y.-old Steamboat Mountain Formation of Thompson and Perry in the area of Broken Ridge. Early phases of volcanic activity produced a crystal-rich, topaz-bearing rhyolite flow followed by eruption of a crystal-poor rhyolite from many local centers. These geochemical characteristics are typical of other topaz-bearing rhyolites in the western United States and suggest that such rhyolites formed as highly differentiated magmas. The 23-m.y.-old Bible Spring fault zone was reactivated after emplacement of the rhyolite flows that resulted in a series of high-angle normal faults. Multiple hydrothermal events resulted in widespread alteration along the faults and concentration of Be, F, Sn, Nb, Mo, Cu, Zn, W, and Ba. Alteration types include silicification, argillization, and alunitization. Crystalline cassiterite and wood tin are widespread and locally abundant in heavy-mineral-concentrate samples from the Broken Ridge area. The only visible cassiterite in the rocks occurs with specular hematite in veins within the silicified topaz-bearing rhyolite, immediately adjacent to a vent breccia. Trace element anomalies of Sn, Mo, Nb, and Be in rock samples well-define the vein area. The combined geologic, geochemical, and structural data suggest that an intrusive may be at depth directly beneath Broken Ridge.

• Research Organization: Geological Survey, Denver, CO (USA)
• OSTI ID: 6875122
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
RHYOLITES
CHEMICAL COMPOSITION
HYDROTHERMAL ALTERATION
PETROGENESIS
PETROLOGY
UTAH
GEOCHEMISTRY
GEOLOGIC FAULTS
GEOLOGY
LAVA
CHEMISTRY
FEDERAL REGION VIII
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
IGNEOUS ROCKS
NORTH AMERICA
ROCKS
USA
VOLCANIC ROCKS
580300* - Mineralogy
Petrology
& Rock Mechanics- (-1989)
580400 - Geochemistry- (-1989)