Close-range photogrammetric techniques and newly available computerized plotting equipment were used to map exploratory trench walls that expose Quaternary faults in the vicinity of Yucca Mountain, Nevada. Small-scale structural, lithologic, and stratigraphic features can be rapidly mapped by the photogrammetric method. This method is more accurate and significantly more rapid than conventional trench-mapping methods, and the analytical plotter is capable of producing cartographic definition of high resolution when detailed trench maps are necessary.

Bulletin of the Association of Engineering Geologi↗

USGS1985

Reconnaissance geologic map of the Ash Shamila quadrangle, sheet 26/40 A, Kingdom of Saudi Arabia

The Ash Shamila quadrangle, sheet 26/40 A, is centred 168 km southwest of Ha’il, in north-central Saudi Arabia, and is bounded by lat 26°30’ and 27°00’ N. and long 40°00’ and 40°30’ E. Access is by way of the Al Madihah – Ha’il paved highway to Hulayfah or Gazzalah, thence by unimproved road to Zarghat, located a few km from the eastern margin and the southeast corner of the quadrangle. Desert tracks lead from Zarghat to the remainder of the area, but a large part of the quadrangle is underlain by the Tertiary and Quaternary Harrat Ithnayn; access over this terrain by vehicle is difficult. The area has low relief, marked only by Paleozoic sandstone remnants, volcanic cones in the harrat, and Jabal Bushra. Drainage on the harrat trends generally northerly, but rainfall is low. The climate is typical of inland Saudi Arabia, with summer day temperatures reaching 45-50°C, and with cold nights. Temperatures can reach 0°C in winter. Vegetation is sparse. The area is sparsely populated, and permanent water is available from wells at Ash Shamila.

Open-File Report↗

USGS1985

Reconnaissance geologic map of the Jabal al Usayfir quadrangle, sheet 26/40C, Kingdom of Saudi Arabia

The Janbal al Usayfir quadrangle, sheet 26/40 C, is located approximately 195 km southwest of the regional center of Ha’il, in the north-central part of Saudi Arabia, and is bounded by lat 26°00’ and 26°30’ N. and long 40°30’ and 40°30’ E. Access is via the Al Madinah – Ha’il paved highway to Hulayfah or Ghazzalah, thence by unimproved road to Zarghat, located a few km from the northeastern corner of the quadrangle. Desert tracks lead from Zarghat to the rest of the area, but a large expanse of the area is underlain by Tertiary to Recent Harrat Ithnayn, and is impassable to land vehicles. The area has low relief, broken by low hills and mesas of Proterozoic and Paleozoic rock, basalt, cinder cones, and Jabal al Usayfir. Drainage in the quadrangle trends generally to the east and southeast, but rainfall is low. The climate is typical of inland Saudi Arabia, with summer day temperatures reaching 45-50°C, and with generally cool nights. Temperatures can reach 0°C in winter. Vegetation is sparse. The area is sparsely populated, and permanent water is found only in wells.

Open-File Report↗

USGS1983

Reconnaissance geology of the Jabal Khatam Quadrangle, sheet 26/39 D, Kingdom of Saudi Arabia

The Jabal Khatam quadrangle encompasses an area of about 2,725 km 2 on the edge of the Precambrian shield in northwestern Saudi Arabia, between lat 26°00' and 26 ° 30' N. and long 39 ° 30' and 40 ° 00' E. The southern one-third and northeastern corner of the area are covered by Tertiary and Quaternary basalt flows of Harrat Khaybar and Harrat Ithnayn. In one small area on its northern edge, Harrat Khaybar is composed of Tertiary rhyolitic tuff and trachyte. Most of the northern one-third and eastern part of the quadrangle are covered by Paleozoic Siq Sandstone. The remainder of the quadrangle is composed of trachyandesite flows, agglomerate, graywacke, and sparse marble of the Hulayfah group and intrusive rocks that range in composition from alkali-feldspar granite to diabase. No deposits with economic potential were found. However, the geothermal potential of the quadrangle warrants further investigation.

Open-File Report↗

USGS1983

Reconnaissance geology of the Ishash Quadrangle, sheet 26/39C, Kingdom of Saudi Arabia

The Ishash quadrangle occupies an area of about 2,725 km2 on the northern border of the Precambrian shield in north-central Saudi Arabia between lat 26?00' and 26?30' N. and long 39?00' and 39?30' E. The northern quarter is covered by Cambrian Siq Sandstone and the southeastern corner is covered by Quaternary to Tertiary basalt. The remainder of the area is underlain by trachyandesite, andesite, and metasedimentary rocks of the lower part of the Hulayfah group and rhyolitic flows and ruffs of the upper part of the Hulayfah group. These rocks have been intruded by rocks that range in composition from gabbro to alkali-feldspar granite. Two small outcrops of Tertiary rhyolite are present in the quadrangle. The predominant structures are folds and faults initiated by the formation of the caldera in the southwestern part of the area. The northerly trending structures were reactivated during the late Precambrian Najd orogenic event and again in the Tertiary during the opening of the Red Sea. No mineral deposits of economic importance were found in the quadrangle.

Open-File Report↗

USGS1975

Geologic map of the Waverly quadrangle, Union and Henderson Counties, Kentucky

Explore the source record for details and available documents.

Geologic Quadrangle↗