Northern Vertex Mining (TSXV: NEE; US-OTC: NHVCF) has reported high-grade gold and silver drill results from a resource expansion drill program on the Ruth vein at its wholly owned Moss gold-silver mine in northwest Arizona, 22 km to the east of Bullhead City and a one and half hour drive south of Las Vegas, Nevada.
Ken Berry, Northern Vertex’s president and chief executive, said the success of its current drill program supports the company’s objective to expand the Moss mine resource base. “The positive drill results achieved from the Ruth Vein and its proximity to the Moss Vein open pit makes it an important target for further testing the possibility of additional resources, pit expansion and mine life extension,” he said in a statement.
The Ruth vein strikes subparallel to the Moss vein, dips to the north into the south-dipping Moss vein and outcrops 150 metres south of the Central pit. Although the outcrop can only be traced on surface for 170 metres along strike, scattered historic pits have exposed veining for another 320 metres to the west. Similar scattered vein exposures can be followed 220 metres to the east, giving the vein a surface expression of 710 metres, the company said.
A north-dipping vein in the hanging wall of the Moss vein outcrops on surface, east of the current pit limit, 1 km farther east of the last indication of the Ruth vein, and extends for 250 metres. The company noted that the vein is similar to the Ruth Vein in width, texture, orientation, and position relative to the Moss vein. The area between the two veins is characterized by scattered veins and stockworks and likely correlates with the Ruth vein, the company said.
As a result, the vein has been named the East Ruth vein.
Highlights from drilling at the Ruth Vein include drill hole AR20-315R, which was drilled to test the intersection of the Ruth and Moss veins and intersected the Moss vein 274 metres downhole and encountered a thick zone of quartz stockwork veining between the two veins. That hole intersected 110 metres grading 0.79 gram gold per tonne and 24.41 grams silver per tonne starting from 185 metres downhole, including 15 metres grading 1.75 grams gold and 41.1 grams silver from 197 metres and 15 metres grading 1.85 grams gold and 85.1 grams silver from 275 metres.
Drilling of the Ruth vein has focused on following up high-grade vein intercepts in the previously reported drill holes AR20-286R and AR20-313R and extending the Ruth vein’s strike length by 150 metres. The drilling has also confirmed the continuity of mineralization at Ruth for 650 metres and the vein remains open to the east and to the west.
In addition to confirming the continuity of narrow high-grade gold and silver mineralization in the vein as shown by drill holes AR20-312R, which intersected 6 metres grading 5.18 grams gold and 37.4 grams silver from 96 metres, and AR20-306R, which cut 5 metres grading 5.62 grams gold and 57.6 grams silver from 90 metres, the recent drilling also discovered thick stockwork mineralization in many places surrounding the Ruth vein, the company noted.
Hole AR20-307R returned 23 metres grading 1.11 grams gold and 14.9 grams silver from 104 metres surrounding a suspected stope mine through the vein, and hole AR20-310R, which intersected 18 metres grading 10.2 grams gold and 26.5 grams silver from 172 metres.
Drill holes AR20-315R, AR20-314R, and AR20-313R demonstrated the continuity of gold-silver mineralization along a down-dip length of approximately 274 metres on the Ruth vein from the surface to the Moss vein intersection, the company reported.
According to the company, modelling indicates that the intersection between the Moss vein and the Ruth vein may become shallower on strike to the east. Additional drilling is underway to target the untested intersection along strike. The discovery of thick mineralization along this extensive zone could, the company noted, lead to the future expansion of the Moss open-pit mine to depth.
“In addition to the success of high-grade gold and silver results from the previously untested Ruth Vein, we are extremely encouraged with the widespread mineralized intercepts encountered at the Gold Bridge and the Gold Tower zones, located directly adjacent to the producing Moss open-pit mine,” Berry stated in the news release.
The Gold Tower target, 500 metres to the west of Ruth, consists of a broad zone of stockwork veining south and west of the West pit. Recent drilling at Gold Tower, the company said, has extended the stockwork mineralization further to the south and west, with several thick zones intersected by many drill holes.
Highlights from drilling at Gold Tower include drill Hole AR20-300R, which returned 49 metres grading 0.74 gram gold and 4.19 grams silver from 38 metres downhole, including 8 metres grading 1.36 grams gold and 5.56 grams silver from 75 metres. A second interval from that hole intersected 35 metres grading 0.59 gram gold and 11.37 grams silver from 162 metres, including 5 metres grading 2.84 grams gold and 48.73 grams silver from 192 metres.
In addition to the stockwork mineralization, some higher-grade veins have been drilled within the stockwork at Gold Tower, such as drill hole AR20-293R, which assayed at 9 metres grading 2.4 grams gold and 2.78 grams silver from 29 metres, the company noted.
To date, 52 holes have been completed at Moss, totalling 5,334 metres of a planned 18,288-metre drill program.
The company is evaluating recent assay results from 15 drill holes — ten holes from the Gold Tower area and five holes from the Ruth vein area — and is also refining its mineralization models.
Ongoing drilling at Moss consists of two reverse circulation drill rigs focussed on the expansion of the Ruth vein, step-outs to the east, and infilling on-strike and down-dip.
The Moss open-pit mine produced a record 14,673 oz. gold-equivalent in the third quarter, up 29% over the previous quarter, and record revenue of US$27 million based on a gold price of US$1,887 per oz. and a silver price of US$25.32 per ounce.
Resources at the project stand at 20.56 million tonnes in the measured and indicated category grading 0.55 gram gold and 6.78 grams silver for 360,000 contained oz. gold and 4.46 million oz. silver. Inferred resources add 11.96 million tonnes grading 0.34 gram gold and 3.59 grams silver for 129,000 oz. gold and 1.38 million oz. silver.
A 2017 preliminary economic assessment (PEA) outlines a low-cost, open-pit mine with a ten-year mine life. The PEA estimates a US$616 million capex for the mine with a payback period of 2.2 years and all-in sustaining costs of US$662 per oz. gold. The after-tax net present value is estimated to be US$93 million at a 5% discount rate with an after-tax internal rate of return of 52.5%.
At press time in Toronto, Northern Vertex was trading at 67¢ per share within a 52-week trading range of 15¢ and 72¢. The company has 251 million common shares outstanding for a $168.4-million market capitalization.