Ivanhoe Mines reports ongoing drilling in the Heruga North zone at it Oyu Tolgoi project in Mongolia intercepted almost 1 km of near-continuous gold and copper mineralization in drill hole OTD1510, making it the longest exploration drill intercept of gold and copper mineralization recorded since Ivanhoe began drilling at the property in 2001. The hole intercepted 112 m grading 1.36 g/mt gold and 0.34% copper. Individual 2-m samples near the bottom of the hole returned gold assays of approximately 10 g/mt, among the highest gold grades ever drilled at Oyu Tolgoi.
Geological modeling indicates Heruga North is the northern continuation of the established Heruga deposit, but with a horizontal displacement of more than 500 m along a fault between the two zones. The top of Heruga North is approximately 1,100 m below surface. Drilling has not been sufficient to define a mineral resource at Heruga North; however, given the dimensions of the zone defined to date, Ivanhoe believes it could have tonnages and grades similar to those in the adjoining Heruga deposit. As of March 2010, the Heruga deposit had an estimated inferred resource of 970 million mt, grading 0.48% copper at a 0.60% copper equivalent cut-off grade, and contained an estimated 10.2 billion lb of copper and 15 million oz of gold.