Edward A du Bray (Former Employee)

A tin greisen deposit is associated with an alkali-feldspar granite that forms part of a ring complex at Jabal as Silsilah. The petrological and geochemical characteristics of the Fawwarah alkali-feldspar granite resemble those of granites located elsewhere that are also associated with deposits of Sn, W and rare metals. The alkali-feldspar granite is peraluminous, incompatible trace...

No abstract available.

No abstract available.

The Al Hufayr quadrangle (27/41 A) lies at the northern edge of the Arabian Shield between lat 27 30' and 28 00' N. and long 41 00' and 41 30' E. A cataclastically foliated syenogranite, the oldest rock exposed in the quadrangle, crops out in a restricted area in the south-central part of the quadrangle. Younger, weakly metamorphosed metarhyolite and minor metabasalt, arkosic sandstone...

The Al Makhul quadrangle (26/42 B) lies in the northern part of the Arabian Shield between lat 26°30' and 27°00' N. and long 42°30' and 43°00' E. Amphibolite, the oldest metamorphic rock exposed in the quadrangle, crops out in a restricted area in the south-central part of the quadrangle. Younger, weakly metamorphosed rhyolite, basalt, and graywacke sandstone on the west edge of the...

The Jabal Saq quadrangle is located in the northeastern part of the Arabian Shield at the northern end of the Najd region between lat 26?00' and 26?30' N. and long 43?00' and 43?30' E. The northeastern two-thirds of the quadrangle is underlain by Paleozoic sedimentary rocks, the southwestern one-third by Proterozoic metamorphic and igneous rocks. The oldest rocks in the quadrangle are...

This 1:500,000-scale compilation shows the distribution of felsic plutonic rocks, lithologic types, and associated mineralization in an area between lat 21° and 24°30’ N., long 43°30’ and 46° E. It is part of a shieldwide compilation being done within the framework of Saudi Arabian Deputy Ministry for Mineral Resources projects 2.04 and 3.12.

In a geochemical evaluation of the eastern and southeastern Arabian Shield, which included collection of 696 rock samples and 694 pan concentrate samples, a province of tin-anomalous granitoid plutons was defined. Pan concentrates collected in and around these plutons were enriched in tin and tungsten relative to the concentrate population. Rock samples of these leucocratic, muscovite...

Sixteen well-defined geochemical anomalies associated with felsic plutons and (or) muscovite-bearing plutons of Proterozoic age have been identified in the eastern and southeastern Arabian Shield. The majority of these plutons are highly evolved, granitophile-element-enriched muscovite-bearing granites that are weakly peraluminous. A followup study of the mineral potential of these...

Pan concentrates were prepared from 265 wadi sediment samples collected during a geochemical reconnaissance conducted between At Taif and Al Bahah to further assess previously identified tungsten anomalies and to locate additional mineralized rock. The samples were analyzed by semiquantitative spectrographic methods for 30 elements, and tungsten was determined by colorimetry. All...

No abstract available.

No abstract available.