Friday, January 30, 2004

Uranium deposits found in Kirthar range

KARACHI, August 06 (PNS): Oxidised uranium mineralisation has been found in the Manchar Formation (Kirthar Range) in Sindh for the first time which, along with other favourable indicators, is 'a significant development'' making it a prime target for uranium exploration.

Assay of selected samples showed uranium values up to 4.5 per cent U3O8. This followed detailed geological studies carried out by Pakistan Atomic Energy Commission (PAEC) scientists in the area. Manchar Formation attracted little attention due to inhospitable working conditions and failure of earlier aero-radiometric surveys to detect anomalous radioactivity. Approximately 200-kilometre area was foot prospected, which revealed six major uranium showings in lower Manchar Formation in the Wahi Pandi, Karunuk (Sehwan) and Rehman Dhora (Aamri) areas.

Anomalies were recorded in lower Manchar Formation in a strike length of over 25kms. Four anomaly sites at Sori, Kukrani, Gaji Kumb and Haleli in Wahi Pandi were found to be 'very promising.'

Uraniferrous zones in sandstone extend from 200-1000m in length. Radioactivity of up to 15,000c-s is encountered in the freshly cut trenches.

Chemical uranium values range from 200ppm to 4.5 per cent U3O8. Uranium minerals have been recognised as carnotite, curienite, phurcalite and saleite. Five geological sections (four in Wahi Pandi and one in Karanuk- Sehwan area) were measured. Data on sedimentological and lithological characteristics of the uranium, host and country rocks was gathered. A total of 185 rock samples were analysed for chemical values and mineralogical studies. Thus another favourable formation in Sindh has now been added for future uranium exploration.

Meanwhile, preliminary exploratory drilling has indicated a sizeable uranium ore deposit at Shanawah near Karak in the NWFP, where continuity of uranium ore was proved over a strike length of 2kms. A total of 32 boreholes to an accumulative 9,329-meter depth were drilled. Ore deposits as thick as 17 metres had been intercepted.

The average thickness is 10 metres while average ore grade is 0.05 per cent U3O8. Carnotite mineral is found in the oxidised (above the water table) zone whereas Uraninite has been identified (through XRD studies) as the dominant mineral in the below water table zone.

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Pakistan Science and Engineering Forum (R)
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