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Andrew Griscom

Publications and source records attributed to Andrew Griscom.

At least 37 records · Page 2Linked to original sources
USGS1983

An aeromagnetic interpretation of eleven map sheets, scale 1:250,000, in the southern Najd and part of the southern Tuwayq quadrangles, Kingdom of Saudi Arabia

Eleven magnetic interpretation maps (scale 1:250,000) have been prepared for the area .of. exposed crystalline rocks in the Southern Najd and part of the Southern Tuwayq quadrangles (scale 1:500,000) from available published data. Boundaries of a variety of rock units that produce distinctive magnetic anomalies .or anomaly patterns are delineated. In some cases these magnetic boundaries correspond with previously mapped geologic contacts, and in other cases they indicate the possibility of additional, as yet unmapped, geologic contacts. The magnetic boundaries also allow the extrapolation of geologic contacts across areas covered by Quaternary deposits. Many boundaries are identified as part of the Najd fault system, and offset magnetic anomalies may be correlated across certain fault zones. Approximate dips were calculated for a few boundaries that represent igneous contacts, faults, or unconformities. Some characteristic anomalies appear to be associated in a general way with areas of gold mineralization and thus provide a guide for further prospecting.

Open-File Report↗
USGS1981

Map showing aeromagnetic interpretation of the Baker-Cypress BLM Instant Study Area and Timbered Crater Forest Service Further Planning Areas, Modoc, Shasta, and Siskiyou counties, California

The data for the aeromagnetic map of the Baker-Cypress and Timbered crater areas were collected in 1978 and compiled at a scale of 1 :62,500 (U,S, Geological Survey, 1979). East-west traverses were spaced at 0.8-km intervals at a constant altitude of 1370 m (4500 ft) above sea level, Contour interval is 20 and 100 gammas, depending upon the steepness of local gradients in the Earth's magnetic field. A regional magnetic field (the International Geomagnetic Reference Field - 1975, updated to the month flown) of approximately 5-6 gammas/km was removed from the data be fore con touring.

California↗
USGS1976

The Alaskan Mineral Resource Assessment Program: Background information to accompany folio of geologic and mineral resource maps of the Tanacross quadrangle, Alaska

The Tanacross quadrangle, consisting of 17,400 km 2 (6,700 mi 2) in east-central Alaska, was investigated by an interdisciplinary research team for the purpose of assessing the mineral resource potential of the quadrangle. This report provides the background information for a folio of maps on the geology, geophysics, reconnaissance geochemistry, Landsat imagery, and mineral resource evaluation of the quadrangle. Revisions to the previously published geologic map of the Tanacross quadrangle, 18 new potassium-argon ages, and a comprehensive bibliography are also included.

Alaska↗