Diamond drilling followed by shallow bedrock drilling has discovered a gold-rich porphyry centre within Xanadu Mines’ Kharmagtai copper-gold district in the South Gobi region of Mongolia. The new discovery has been named Altan Burged or Golden Eagle and is about 2.5km east of the Altan Tolgoi, Tsagaan Sudal and Zesen Uul copper-gold deposits.
The diamond hole intersected 220 metres from a depth of 42 metres grading 0.64 g/t gold and 0.15% copper, including 102 metres from 42 metres @ 1 g/t gold and 0.15% copper. This broad intersection includes a shallow zone of supergene gold enrichment of 26 metres from 42 metres @ 2.27 g/t.
Both oxide and primary gold and copper mineralisation were intersected in the hole. The shallow higher grade oxide mineralisation is hosted in a strongly silicified and clay altered zone above a quartz monzodiorite porphyry stock, with fine-grained visible gold observed in core.
Primary gold and copper mineralisation is associated with high density centreline quartz-sulphide veins and strong albite-chlorite-pyrite alteration. This is similar to the high-grade Zesen Uul porphyry and is interpreted to be related to same porphyry mineralisation event, confirming a district-scale mineral event.
The gold-rich Altan Burged porphyry was discovered in December as part of Xanadu’s highly successful bedrock drilling program.
The intersection in the diamond hole represents a significant development for Xanadu’s ongoing exploration efforts within the Kharmagtai district. While exploration of this emerging porphyry centre is still at an early stage, the width, intensity of alteration and porphyry stockwork mineralisation and tenor of the gold mineralisation intersected is very encouraging.
Xanadu’s managing director and CEO Dr Andrew Stewart said, “The results of this first
diamond drill hole are very exciting. The discovery of a new porphyry centre under shallow cover adds further weight to the geological model for the Kharmagtai district as an emerging porphyry district comprising multiple centres of copper-gold and gold mineralisation.
“It also validates our under cover targeting methods and the importance of these techniques as key exploration tools in unlocking the potential of the large porphyry district. The current diamond drill program will now focus on delineating the near-surface oxide gold enrichment zone and target the highest-grade primary portions of this new porphyry system.”
Mineralisation remains open along strike and down dip with the hole finishing in low density stock work mineralisation grading higher than 0.2 g/t gold.
The current exploration target dimensions are 500 metres long by 300 metres wide and initial drilling indicates that there is potential for Altan Burged to host a significant high-grade porphyry gold-copper deposit adjacent to the three outcropping porphyry deposits of Altan Tolgoi, Tsagaan Sudal and Zesen Uul where Xanadu has already defined more than 1.5 million pounds of copper and more than 2 million ounces of gold resource.