Geology topics

Conrad Martin

Publications and source records attributed to Conrad Martin.

3 recordsLinked to original sources

USGS1979

Titaniferous magnetite in the layered intrusive complex at Lakathah, Kingdom of Saudi Arabia

The Lakathah layered intrusive complex about 90 km east of Qunfudhah contains significant resources of low-grade titanium-bearing rock. The complex is about 10 km in diameter and consists of three principal units: an outer syenite ring, an intermediate diorite-gabbro zone, and a central pyroxenite-hornblendite core. The principal mineralization zone is in the ultramafic core of the complex. The titanium is mainly in titaniferous magnetite, but some is in ilmenite intergrown with magnetite and in the titanium-bearing hornblende, kaersutite. The titaniferous magnetite is in concordant lenses and veinlets and is disseminated throughout the host rock. The lenses and veins range from a few centimeters to 3 m in width and are as much as 50 m long. The layered disseminated bodies contain as much as 25 percent magnetite. Exploratory drilling showed that an area 500 by 1000 m contains titaniferous rock averaging about 6.2 percent TiO2. This mineralized zone contains about 175,000,000 tons per 100 m depth. Material of this grade is not commercial at this time, but may be a future resource. Alluvial deposits along the Red Sea near Al Qunfudhah should be tested for possible deposits of titaniferous sand.

Open-File Report↗

USGS1970

An appraisal of the Jabal Idsas magnetite mineralization based on diamond drill hole N40A

Diamond Drill Bole N40, intended to test the magnetite mineralization at Jabal Idsas, was aborted because of technical difficulties and a new hole, N4OA, was drilled at the same site in February of 1968 to an inclined down-the-hole depth of 445.7 meters. Disseminated magnetite and locally massive lenses, veins, and breccia fillings of magnetite were encountered along most of this length, but more consistently between the depths of 82 and 435 meters. The average iron content of this section in the form of magnetite was 16.4 percent. Several sections, each about 20 meters in length, contained from 22.4 to 31 percent iron. Extrapolation of costs from current taconite iron ore operations in the United States, beneficiating ores averaging 23 percent iron, suggests that ore of similar or possibly lower iron content from Jabal Ideas could be mined and processed at comparable if not at somewhat lower costs. The beneficiation product, containing about 64 percent iron, would have a current value of $16.00 per long ton at the point of use. On the basis of information presently available there is a reasonable expectation that reserves of the order of 75 to 125 million tons could be developed at Jabal Ideas to sustain a similar operation. Tin, not previously reported from this district, was found in the cores in small but widely distributed amounts averaging perhaps .01 percent. Although the amount is anomalous it is probably not of economic significance in the magnetite area, but one should not at this stage discount the possibility of finding higher concentrations of tin elsewhere in the district. The origin of the magnetite in this geologic setting is attributed largely to the uralitization of high-iron pyroxene. It is believed that this interpretation is a more useful guide to further exploration than other explanations previously adduced.

Jabal Idsas↗

USGS1970

Preliminary investigation of cement materials in the Taif area, Saudi Arabia

A preliminary investigation of possible sources of cement rock in the Taft area was made during the latter part of August 1968. Adequate deposits of limestone, clay, quartz conglomerate and sandstone, and pisolitic iron ore, yet no gypsum, were located to support a Cement plant should it prove feasible to establish one in this area. These materials, made up mostly of Tertiary and later sediments, crop out in isolated, inconspicuous low hills in a north- trending belt, 10 to 15 kilometers wide, lying about 90 kilometers to-the east of At Taft. The belt extends for more than 90 kilometers from the vicinity of Jabal 'An in the south to the crushed rock pits at Radwan and beyond in the north. The area is readily accessible either from the Talf-Riyadh highway or from the Taif-Bishah road presently under construction. The limestone, which is quite pure and dense in some localities but dolomitic, argillaceous, and cherty in others, occurs in a variety of colors and would make suitable decorative building stone. The volcanic rocks of the Harrat Hadan, lying directly to the east of the limestone belt, include volcanic ash beds some of which may have been altered to bentonitlc clays. Others may have been lithified and might be suitable for light-weight aggregate. These possibilities remain to be investigated. Precambrian metamorphic rocks lying directly to the south and southeast of Taif were also investigated as possible cement rock sources, but no suitable material was found here.

Open-File Report↗