Duration of hydrothermal activity at Steamboat Springs, Nevada, from ages of spatially associated volcanic rocks / by M.L. Silberman [and others].
| Other author/creator | Silberman, Miles L. |
| Format | Book and Print |
| Publication Info | Washington : U.S. Govt. Print. Off., 1979. |
| Description | 14 pages : map ; 29 cm. |
| Subject(s) |
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| Series | Geology and geochemistry of the Steamboat Springs area, Nevada Geology and geochemistry of the Steamboat Springs area, Nevada. UNAUTHORIZED |
| Contents | Abstract -- Introduction -- Regional geologic relations -- Geology of the area near Steamboat Springs -- Structural control of hot-spring activity -- Alteration and ore minerals -- Ore minerals, trace-metals, and isotopic compositions -- Geologic limits on the time span of hydrothermal activity -- Potassium-argon ages -- Samples -- Basaltic andesite -- Rhyolite domes -- Altered basaltic andesite -- Interpretation -- Implications of the age of the Steamboat Spring thermal system -- Steamboat Springs as related to other thermal systems and hydrothermal ore deposits -- Methods of sample preparation -- References cited. |
| Summary | Steamboat Springs is a presently active equivalent of epithermal gold-silver ore-forming systems. Hot-spring sinter deposits contain small amounts of gold, silver, mercury, antimony, and arsenic. Hot-spring activity probably started before extrusion of the basaltic andesite of Steamboat Springs. Old sinter from the Steamboat Springs system occurs in gravels above and below the basaltic andesite. Intense hydrothermal alteration, including almost complete replacement by hydrothermal potassium-feldspar, has affected the basaltic andesite. Three plagioclase separates of differing potassium content from fresh basaltic andesite yielded potassium-argon ages of 2.52 to 2.55 m.y. Basaltic andesite almost completely replaced by potassium-feldspar yielded an age of 1.1 m.y. The source of energy for the thermal convection system is probably a large rhyolitic magma chamber that supplied the pumice and from which the rhyolite domes were emplaced. Sanidine and obsidian from four of the rhyolite domes yielded potassium-argon ages of 1.15 to 1.52 m.y. and obsidian from one of the northeastern domes yielded apparent ages of 2.97 and 3.03 m.y. The data indicate that hydrothermal activity has occurred at Steamboat Springs, possibly intermittently, for more than 2-1/2 m.y. These data agree with other radiogenic age studies indicating 1- and 2-m.y. lifetimes for the hydrothermal systems that generate epithermal gold-silver deposits. |
| Local note | Joyner- FOR JOYNER LIBRARY HOLDINGS OF THE SERIES, GEOLOGICAL SURVEY PROFESSIONAL PAPER, SEARCH BY CALL NUMBER QE75 .P9. |
| Bibliography note | Includes bibliographical references (pages 13-14). |
| Issued in other form | Online version: Silberman, Miles L. Duration of hydrothermal activity at Steamboat Springs, Nevada, from ages of spatially associated volcanic rocks |
| LCCN | 79016870 |
| Govt. docs number | I 19.16:458-D |
Available Items
| Library | Location | Call Number | Status | Item Actions | |
| Joyner | General Stacks | QE75 .P9 NO. 457-458 | ✔ Available | Place Hold |
Items Bound With This Item
Geology and volcanic petrology of the Lava Mountains, San Bernardino County, CaliforniaHydrology, activity, and heat flow of the Steamboat Springs thermal system, Washoe County, Nevada
Regional geology of the Steamboat Springs area, Washoe County, Nevada
Rocks, structure, and geologic history of Steamboat Springs thermal area, Washoe County, Nevada