Monoyal - Porphyry Copper, Gold and Molybdenum Target

  • Wide intercepts of copper and molybdenum identified in drill holes
  • Mineralisation covers a 1 km long by 800 m wide area
  • Recent outcrop sampling extends the area of known mineralisation to the North West

The porphyry copper model


  • Porphyry copper-gold deposits form in a large body of molten rock of granitic composition, that has been fractured on a fine-scale and impregnated with disseminated sulphide mineralisation, often containing copper, gold and other minerals
  • The preliminary review of drill data by Phil Jones suggests the geochemistry and mineralisation characteristics of the holes drilled at Monoyal show GMN are drilling above the main zone of copper mineralisation
  • Monoyal is a calc-alkaline intrusive, whilst these are rare in PNG, they provide significant potential for large deposits
  • Calc alkaline intrusives in the region include:
    • Batu Hijau (968 Mt @ 0.41% Cu and 0.26 g/t Au)
    • Panguna (1.84 Bt @ 0.30% Cu and 0.34 g/t Au)

1.1 Monoyal Porphyry Model



IMG 1495

After being first recognized as an elliptic topographic feature, field work at Mongae Creek identified an abundance of coarse, angular and crystalline gold in the drainage system of a small valley where local miners are consistently recovering alluvial gold. Following a mapping campaign that encountered classic porphyry-style alteration and veining, Mongae Creek became The Company’s priority target.

Samples recovered from mineralised outcrop and proximal floaters retrieved from the creeks have returned grades of up to 0.6 % Cu and 0.44 g/t Au. Gossanous, hydrothermally brecciated diorite is found in outcrop and as floaters in the creeks. These floaters are being crushed by locals and yield free gold.


A scout diamond drill programme commenced in 2018 and the first two drill holes have been completed. Assay results have been received for both holes. MCD002 returned a best intercept of 49m @ 0.12% Cu from 165m including 10m @ 0.22% Cu from 183m. In MCD001, the best intercept was 1m @ 243 g/t Ag, 0.8 % Cu, 522 ppm Co, 0.4 % Ni, and 0.7 % W from 38m. In both holes, the frequency of base-metal and Mo-bearing veinlets increases downhole, as do K, Cu, Zn, Mo and Pb grades. This is consistent with logging by field geologists of more intense alteration further down the hole and suggests closer proximity to a mineralising fluid source.The holes display chloritic and propylitic alteration, characteristic of a pophyry copper-gold system.

Gold Mountain has commenced a detailed surface soil sampling programme over the entire catchment basin to assist in the next phase of targeted drilling.


Monoyal photos