NIUMINCO Group Limited has obtained pleasing initial results from the early stages of its drilling programme at the Enterprise vein system (Chimney Area) at the Edie Creek mine in Morobe Province.
The programmne was designed to drill a total of approximately 350 to 500 metres in ten angled diamond core drill holes spread over five drill platforms utilising one of Niuminco’s drill rigs and crew.
This very shallow drilling programme was also designed to define a JORC resource in the near surface highly oxidised outcropping quartz vein system and importantly, to define potential sources of high grade material to feed an upgraded wet gravity concentrating plant at the rate of 40 to 60 tonnes per day.
To date every hole has intersected gold bearing vein material but also backfilled mine openings which occur adjacent to each of these intersections.
Niuminco reported that Drill hole EDD022 penetrated a backfilled mine opening from 39m to 40m adjacent to and between two high grade vein intersections.
The company’s efforts have been hampered by the fractured ground and continuous, cavernous veins at Enterprise, which has seen drilling yielding less than 50% core recovery of the oxidised veins and an inferred large gold loss.
However, the company believes that the results from the drilling programme indicate that the veins at the Enterprise system grade at 9-10g/t Au, and are continuous and cavernous over a 500m strike.
Each of the holes contained a higher grade vein section conforming to the predicted west- dipping vein model.
Assay results on the six completed drill holes include:
- EDD 019 intersected 5.4m @ weighted average of 2.97g/t Au and 94g/t Ag from 8m depth, including:
o 2m @ 6.89g/t Au and 195g/t Ag from 10m.
- EDD 020 intersected 9m @ weighted average of 1.07g/t Au and 62g/t Ag from 12m, including:
o 1m @ 4.06g/t Au and 21g/t Ag from 13m.
- EDD 022 intersected 1.0m @ 13.4g/t Au and 473g/t Ag from 32m and 3.0m @ weighted average of 4.61g/t Au and 100.3g/t Ag from 38m, including:
o 1.0m @ 8.98g/t Au and 88.5g/t Ag from 38m.
- EDD 023 intersected 4.4m @ 1.66g/t Au from 43.4m and 0.30m @ 6.07g/t Au from 53.5m ( a footwall remnant), including:
o 1.4m @ 3.2g/t Au from 43.4m.
- EDD 021 intersected 3.4m @ weighted average of 2.03g/t Au and 143g/t Ag from 35m, including
o 2.1m @ 3.04g/t gold and 167g/t Ag from 35m.
The Enterprise Mine was developed immediately prior to World War II, but no production occurred. Detailed underground sampling was reported in 1940 prior to abandonment due partly to the Japanese invasion of New Guinea and partly to a flooding incident at the nearby Edie Mine.
The mine saw substantial level development but no stoping and production, so that there is ore defined by sampling that was never exploited.
Calculations by Mincor Resources NL in 2013 established potential for 35,000 ounces in 4 adjacent blocks. The reliability of the underground sampling is not questioned, however this sampling cannot be used to compile a JORC compliant resource.
The immediate target at Enterprise is the shallow exposure at the southeast end of the lode in a Block described as EP-1a where potential for 1,000 ounces was calculated by Mincor Resources NL. This was based on surface channel sampling over a 60m section, and a 100m section on the Level 1 development drive.
The surface sampling involved 30 lines of samples on 2m spaced lines with 3 samples per line. Each line of 3 samples comprised a hanging wall selvedge sample, a sample of the lode itself and a footwall sample. The channel samples of lode averaged 9g/t.