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

Open-File Report 70-215
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Abstract

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. 

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Publication type Report
Publication Subtype USGS Numbered Series
Title An appraisal of the Jabal Idsas magnetite mineralization based on diamond drill hole N40A
Series title Open-File Report
Series number 70-215
DOI 10.3133/ofr70215
Year Published 1970
Language English
Publisher U.S. Geological Survey
Description 29 p.
Public Comments (IR)SA 111
Country Saudi Arabia
Other Geospatial Jabal Idsas
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