Mapping at Marengo identifies two intrusion-related Au/Cu systems
The Board of Papua Mining (LON: PML), is pleased to announce that field mapping and rock sampling at the Company’s 100%-owned Marengo Gold Project in Queensland, Australia has defined two intrusions with multiple veins, hosting strongly-anomalous gold, copper and silver mineralisation up to 59g/t Au, 4.58% Cu and 297g/t Ag at surface. A new copper/silver target has been discovered in an area known as Bee Creek, with high grade copper, silver and gold up to 17.7% Cu, 342g/t Ag and 2.9g/t Au.
· Faults, ring-fractures, abundant veining, sulphides and alteration form circular patterns which highlight two intrusion-related gold/copper systems;
· Mapping and sampling has discovered a new area known as Bee Creek. This new target hosts un-mapped and unexplored old mining shafts with significant copper up to 17.7% and silver to 342g/t;
· In addition to the Lighthouse Project, Marengo provides PML with another outstanding opportunity for organic growth via the potential for a significant gold/copper/silver discovery;
· Of 69 rock samples collected, the maximum assays are 59.4g/t Au, 17.7% Cu and 342g/t Ag;
· 28% of rocks returned assays above 1.0g/t Au, with an overall average grade of all rocks collected being 3.6g/t Au;
· The geomorphology, geology, mineralogy and surface geochemistry at Marengo has a number of important similarities to the Didipio Gold Mine in the Philippines (2Moz gold and 260,000t copper);
· Gradient Array Induced Polarisation (IP) geophysics is planned for Marengo to assist detailed drill targeting;
· Preparations for RC drilling at Double Event (part of the Lighthouse Project) is underway.
Chief Executive Officer of Papua Mining, David Price commented:
“Our recent work at Marengo has identified two previously-unidentified intrusion-related gold/copper circular features characterised by porphyritic rocks, high-grade copper/gold mineralisation at surface, strong alteration and geologically-important ring fractures, faults and vein-swarms. The discovery of high grade copper and silver at Bee Creek is an exciting development which supports our belief that Marengo is showing potential for the discovery of a significant gold/copper/silver mineralising system. Papua now has a second project which provides a pathway for strong, organic-growth for the Company. Our objective of growing PML through discovery and development is enhanced by the identification of these two exciting systems at Marengo.”
Papua Mining has completed rock sampling and structural mapping at the One Mile Mountain and Homeward Bound Prospects which form part of the Marengo Gold Project. Sixty-nine (69) surface rock samples have been collected from available outcrop. A complete list of all rock sample results is provided at the bottom of this announcement. There are 37 historical gold workings at Marengo, some with hand-dug shafts more than 45ft deep, which is testimony to significant gold winnings at the time.
During their recent field mapping, PML geologists reported large regional faults, semi-regional ring-fractures, abundant veining, sulphides (pyrite and chalcopyrite) and epidote alteration. On compiling the mapped geological features, two distinct circular patterns are evident which strongly suggests that two separate, intrusion-related gold/copper systems have been encountered.
In support of this conclusion, anomalously high Bismuth/Tellurium ratios (0.42% Bi / 244ppm Te) highlight a reduced mafic, intrusion-related mineralising setting – the core of which correlates well with high gold-in-rock samples. The Bi/Te ratios highlight a “bullseye” target on the northwestern edge of the Homeward Bound System and is proximal to the centre of the mineralising system.
The One Mile Mountain System consists of a medium-grained, porphyritic hornblende/biotite diorite, which has its mafic mineral component largely altered to chlorite. Surrounding and partly intruding into One Mile Mountain, granodiorite, altered gabbro, altered diorite and a swarm of abundant northwest-striking aplite dykes have been mapped.
Reconnaissance mapping has also identified a new target area approximately 2km northwest of One Mile Mountain with high grade copper (17.7%) and silver (342g/t Ag). Little is known about this new area, known as Bee Creek but further work to be undertaken at Marengo will include this new area.
An image showing the circular features at One Mile Mountain and Homeward Bound is available at the following link. This interpretation map includes both historical and recent geochemical sampling for completeness.
Marengo demonstrates a number of similarities to the Didipio gold/copper deposit in the Philippines which hosts a resource of 2 million ounces of gold and 260,000 tonnes of copper metal and is currently in production.
· Didipio is similarly hosted within a multiphase intrusion and consists of a gabbro-diorite-monzodiorite intrusive complex;
· Both projects have a prominent 400m-long ridge;
· Post-mineralisation andesite dykes occur at Didipio and have also been mapped at One Mile Mountain;
· Chalcopyrite and pyrite are the dominant sulphides at Didipio, both of which have been observed at Marengo, but this similarity is inconclusive at this early stage of exploration;
· Both projects are characterised by northwest faultsets and east-west veinsets;
· Weak biotite alteration is associated with the diorite at Didipio and replacement biotite is clearly identified at Marengo;
· Quartz stockwork hosts much of the low-grade gold (between 1.0 and 2.0 g/t Au) at Didipio and a similar grade range is observed in the swarm of aplite/quartz veins at Homeward Bound (average rock sample grade of 2.7g/t Au);
· Didipio has a silver telluride mineral called Hessite (Ag2Te). The very high silver (342g/t Ag) and tellurium (244ppm Te) at Marengo may suggest the presence of Hessite but this is yet to be confirmed by petrology;
BACKGROUND AND HISTORY AT MARENGO
The Marengo Goldfield was the subject of a gold rush during the late 1870’s and the project hosts thirty-seven (37) gold diggings within multiple, hornfelsed intrusive events, displaying varied composition, alteration and mineralisation. Chalcedonic silica, banded quartz/sulphide epithermal veins and hydrothermal breccias have all been identified, particularly in the area surrounding One Mile Mountain. Limited modern exploration has been undertaken and PML management considers the potential for discovery to be very high. Hand-picked production is recorded as averaging 2oz/t Au (60g/t Au).
Anomalous geochemistry has been detected from numerous sampling campaigns between 1968 and 1989, with rock samples up to 149.8g/t Au, 92g/t Ag and 2.16% Cu and costeaning (shallow channels) have returned 12m @ 6g/t Au. Thirty-nine (39) drill holes have been drilled by previous explorers, mostly to the south of One Mile Mountain. Importantly, twenty nine (29) of these holes are vertical, rendering this drilling less than optimal, as mineralisation is also mostly vertical. Recoveries from this drilling were very low, with gold potentially being lost.
The first work programs at Marengo were put together by Intek Services when they acquired the tenement in 1981. Intek undertook rock chip sampling of the individual reefs, as well as semi-regional stream sediment sampling which focused on One Mile Mountain. This work concluded that One Mile Mountain required more follow-up work, however only low-level work continued until 1987, when the tenement was acquired by Xenolith Gold. Xenolith completed rock sampling which identified high-grade gold and silver at the historical workings including;
· Flat Reef – average assays of 5.4g/t Au and 50.2g/t Ag
· Westwood – average assays of 2.1g/t Au and 9.0g/t Ag
· Homeward Bound – assay range from 0.3g/t – 149.8g/t Au and 1.0g/t – 92g/t Ag.
It was noted that all samples were collected from quartz veins within shear zones. Xenolith continued its exploration in 1988 by drilling 38 RC drill holes. These holes were drilled at the following locations;
· Homeward Bound – 5 holes (PD1 – PD5)
· Toomeys – 4 holes (PD6, 7, 8, 8A)
· Westward – 8 holes (PD9 – PD16)
· Flat Reef – 22 holes (PD17 – PD39)
The vertical holes are not considered appropriate, as most of the mapped, mineralised veins are vertical or steeply dipping. The better results from this drilling came from the Homeward Bound Prospect, where PD1 intersected 3m @ 0.52g/t Au from 32m and PD5 with 5m @ 0.4g/t Au from 16m depth. Of particular note is that only 48 samples from 200m of drilling were actually analysed, despite fresh sulphides being observed and recorded in the historical drilling logs.
If anyone reads this article found it useful, helpful? Then please subscribe www.share-talk.com or follow SHARE TALK on our Twitter page for future updates.
Terms of Website Use
All information is provided on an as-is basis. Where we allow Bloggers to publish articles on our platform please note these are not our opinions or views and we have no affiliation with the companies mentioned