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M.A. Chaffee

Publications and source records attributed to M.A. Chaffee.

At least 55 records · Page 3Linked to original sources
USGS1984

The Conterminous United States Mineral Appraisal Program; background information to accompany folio of geologic, geochemical, geophysical, and mineral resources maps of the Walker Lake 1 degree x 2 degrees Quadrangle, California and Nevada

The Walker Lake 1? by 2? quadrangle in eastern California and western Nevada was studied by an interdisciplinary research team to appraise its mineral resources. The appraisal is based on geological, geochemical, and geophysical field and laboratory investigations, the results of which are published as a folio of maps, figures, and tables, with accompanying discussions. This circular provides background information on the investigations and integrates the information presented in the folio. The selected bibliography lists selected references to the geology, geochemistry, geophysics, and mineral deposits of the Walker Lake 1? by 2? quadrangle.

Circular↗
USGS1984

Summary geochemical maps, Hoover Wilderness and adjacent study area, Mono and Tuolumne counties, California

The Hoover Wilderness and the adjacent Hoover Extension (East), Hoover Extension (West), and Cherry Creek A Roadless Areas (the adjacent study area) encompass approximately 153,900 acres (241 mi 2 ; 623 km 2 ) in the Inyo, Stanislaus, and Toiyabe Naitonal Forests, Mono and Tuolumne Counties, Calif. These two areas lie along and mostly east of the crest of the Sierra Nevada, along the north and east sides of Yosemite National Park. Elevations vary from a high of 12,446 ft (3,793 m) on the crest of the Sierra Nevada to a low of about 6,500 ft (1,981 m) near the Bridgeport Ranger Station. Access to the Hoover Wilderness and adjacent study area is by U.S. Highway 395, California State Highways 108 (Sonora Pass) and 120 (Tioga Pass), and by other paved and graded roads that lead off of these U.S. and State highways.

California↗
USGS1983

Scoresum - A technique for displaying and evaluating multi-element geochemical information, with examples of its use in regional mineral assessment programs

A technique called SCORESUM was developed to display a maximum of multi-element geochemical information on a minimum number of maps for mineral assessment purposes. The technique can be done manually for a small analytical data set or can be done with a computer for a large data set. SCORESUM can be used with highly censored data and can also weight samples so as to minimize the chemical differences of diverse lithologies in different parts of a given study area. The full range of reported analyses for each element of interest in a data set is divided into four categories. Anomaly scores — values of O (background), 1 (weakly anomalous), 2 (moderately anomalous), and 3 (strongly anomalous) — are substituted for all of the analyses falling into each of the four categories. A group of elements based on known or suspected association in altered or mineralized areas is selected for study and the anomaly scores for these elements are summed for each sample site and then plotted on a map. Some of the results of geochemical studies conducted for mineral assessments in two areas are briefly described. The first area, the Mokelumne Wilderness and vicinity, is a relatively small and geologically simple one. The second, the Walker Lake 1° × 2° quadrangle, is a large area that has extremely complex geology and that contains a number of different mineral deposit environments. These two studies provide examples of how the SCORESUM technique has been used (1) to enhance relatively small but anomalous areas and (2) to delineate and rank areas containing geochemical signatures for specific suites of elements related to certain types of alteration or mineralization.

Journal of Geochemical Exploration↗