The Company holds a large and strategic tenement package along the under-explored northern margin of the New Guinea Mobile Belt, (within the Thrust Belt), which hosts numerous world-class gold and gold-copper deposits. Major greenfields discoveries continue to be made in this belt, for example Harmony Gold's Kili Teke copper-gold prospect of several million oz. in gold & gold equivalents, and the northern margin of the belt where GM's tenements are located is much less explored than elsewhere.
The New Guinea Mobile Belt is one of the most prospective island arc porphyry copper/gold provinces in the world. Within the Thrust Belt, Crustal scale thrust faults host fragments of obducted oceanic crust & the terrane is characterised by late Miocene, sub-horizontal to shallowly north-dipping, stacked thrust sheets of regionally metamorphosed and strongly cleaved Triassic to Eocene fine-grained sedimentary rocks and minor volcanic rocks.
Well defined "arc-normal" crustal scale lineaments together with associated very large scale regional WNW-ESE arc parallel faults such as the Ramu-Markham suture provide ideal conduits for the mineralising fluids associated with epithermal quartz vein gold, "TAG" or thermal aureole gold and for the emplacement of porphyry copper/gold intrusive complexes but nevertheless the area has had no modern systematic comprehensive geophysical exploration to date.
The presence of large volumes of auriferous alluvial gold and numerous hardrock chip samples with high gold grades indicates that Gryphon's tenements are prospective for both economic alluvial/palaeoalluvial deposits and bedrock gold deposits from which the alluvial gold is sourced. The bedrock prospectivity includes porphyry copper-gold & associated skarn type deposits & in principle, Thermal Aureole Gold (TAG) targets and epithermal quartz vein hosted gold. Such targets are very much under-explored within Gryphon's tenements and have not been explored for at all with a full suite of modern geophysical methods.
Over the last decade or so there have been ground breaking new geophysical techniques developed (ZTEM, 3D IP and the ULTRAMAG suite of drone magnetics, drone LIDAR and deep reading GPR for example) and also progressive incremental improvements in the more traditional long-standing techniques (such as aeromagnetic, radiometric and airborne gravity surveys) which now enable much clearer and more rapid definition of drilling targets.
The dominant terrane in Gryphon's vast tenement holdings consist of rugged hilly to mountainous tracts of land characterised by abundant anomalous gold values in 80 mesh sieved samples and pan concentrates in most of the streams and watercourses throughout the tenements; many of which are actively being worked by itinerant artisanal miners using simple hand tools and very small scale mechanised floating dinghy dredges and high bankers.
The minority of the ground holdings consist of flat or gently sloping ground composed of modern alluvials & Tertiary age palaeo-alluvials. It is only the modern alluvials in the steeper ground that have had any attention by artisanal miners and neither the modern alluvials nor the palaeo-alluvials have been subjected to modern western exploration and exploitation methods. Independent assessment of the bulk volume of palaeo-gravels available ranges from 2.5 to 7.3 billion cubic metres. Visible gold is present in over 75% of recently taken samples from both modern & palaeoalluvials but apart from one area in the centre of EL 2431 where 65 bulk samples showed an average grade of 2.5g/m3, none of the modern alluvials nor the Tertiary palaeoalluvials have been thoroughly sampled as part of a cogent exploration & development initiative.
Because of PNG's mountainous terrain, forest cover and deep soil profile, conventional geochemical sampling programs to define drill targets are expensive, time consuming, and sometimes do not succeed in delineating the primary sources of the anomalous gold.
GM's plan to use the latest regional airborne geophysical techniques to prioritize focus areas for much more intense surveying leading to target definition is the right approach and will significantly reduce the time taken to reach drill testing stage. Furthermore, experience elsewhere in PNG shows that using ground geophysics in the follow up phase greatly assists in defining drill targets. There may also be scope for applying the emerging new technology of detailed drone-based surveying & DGPR in the follow up phase (the ULTRAMAG suite of technologies for example).
Such an approach at the Mt Nakru copper-gold deposit in New Britain (11 tonnes of gold defined to date with much upside potential) is a good example of where geophysical techniques succeeded when extensive geochemistry and sampling surveys over many years failed to identify the main ore body.