Sentosa Mining has started a reverse circulation drilling program on its Darvii Naruu Copper-Gold Project in western Mongolia’s Gobi Altai province to test 4 of 37 anomalies identified by a recent airborne geophysics survey conducted over the north western sector of the project.
A 2000-metre scout drilling program is now ongoing at the highest priority targets comprising the Mushroom Reef, Mushroom East, Sulphide Creek and Anomaly 13 prospects.
Supporting the prioritization of drill targets is recent analysis of surface rock chip samples from field work completed in 2012 with gold grades of 10.8 grams/tonne, 7.8 grams/tonne and 1.2 grams/tonne from float at Anomaly 10. Sentosa acquired a 100% interest in Darvii Naruu on October 1 and has since raised $1.14 million in an over-subscribed issue, primarily to fund its first drilling on the project.
The copper and gold mineralization of Mushroom East prospect is associated with sub-parallel sheeted quartz veins within a mafic intrusion. The width of the laminated veins varies from 0.25 to 1.0 metre. The mineralization outcrops on the side of a hill and is visible from a distance by its gossanous nature.
The outcrop extent is approximately 75 metres, however malachite was observed in outcrop within a similar mafic intrusion 300 metres to the WNW of the system. Three holes for 330 metres have been designed to test the Mushroom East copper prospect at depth. High-grade rock chips from outcrop up to 5.5% copper exist at this location and recent analysis of rock chips collected in 2012 within the area returned grades of greater than 1% copper.
Further ground inspection is required at Sulphide Creek after Southern Geoscience identified a strong magnetic anomaly coincidental with moderate level stream sediment sampling up to 398 ppm nickel and 49 ppm cobalt. These are not high but the interest lies in a train of large boulders of fine grained variously serpentinized dunites and peridotites.
These carry up to several per cent fine grained disseminated sulphides and a number of specimens assay 0.5% to 0.6% nickel and 110 ppm cobalt. In this area, some stream sediments carry up to 13 ppb gold. The presence of nickel sulphides and the gold in the stream sediments suggests this area is prospective for PGEs as well as nickel.
A large magnetic high with a peculiar circular magnetic low exists at Anomaly 13, and was identified in the review by Southern Geoscience. This anomaly has a partially overlapping potassic anomaly. Stream sediment sampling identified this as an area of interest in 2008. Elevated nickel values in gossan from outcrop with values up to 0.6% nickel and a float sample grading 21% copper, 2.1 grams/tonne gold, 0.37% potassium and 0.37% palladium was found in this vicinity. Further ground truthing will be completed at Anomaly 13 prior to drilling a hole at this priority target.
Sentosa has also commissioned an independent technical review of the geology and geochemistry of the project. This work has confirmed the potential for large scale copper-gold, gold or nickel-copper gold PGE mineralized systems within the north western sector of Darvii Naruu.