Background to the New Britain Project
The PM Group holds six Exploration Licences on New Britain island with a total area of 1,112 square kilometres. Most of the licences are in West New Britain Province In addition to the currently held ground, the Group has three licence applications pending.
The New Britain licences cover an area which straddles the so called Kulu-Fulleborn Trend, a NW-SE trending belt of mainly intermediate volcanic rocks and associated, sub-volcanic intrusives which host a number of historically reported porphyry copper mineralisation targets, particularly those at Simuku, Plesyumi and Nakru.
The main contiguous block of licences held and under application covers an irregular elongated shape between Kimbe, the capital of the West New Britain province, on the north coast, to Fulleborn on the south coast. Kimbe has a deep water port that can be used to bring in vehicles and drilling equipment. The area around Kimbe is covered for the most part with oil-palm plantations and has a good road infrastructure and access to this area is therefore relatively easy. Apart from the area around Kimbe most of the Exploration Licence areas are covered by dense tropical rain forest with patchy areas of secondary growth where logging and subsistence farming has been carried out.
The central part of the main licence block is dominated by the rugged Whiteman Mountain ranges which have altitudes ranging from 200m to 1,830m above sea level at the highest point. Numerous rivers and streams dissect the area and drain to the north and south coasts from the ranges. Access to parts of EL 1462 is difficult and in some instances prospects can only be reached on foot or by helicopter. However the Mt Nakru area which includes our most advanced exploration targets at Tripela, Junction and Flying Fox has road access via a logging track.
Papua Mining’s Exploration on New Britain
The Papua Mining team assembled a large database from previous exploration programmes on New Britain Island and followed this with a reinterpretation of all available geophysical data for the project area. This work produced a significant number of high priority target areas. Using the results of the studies, the Company embarked on a major field program in June 2010 to follow up and test a number of these targets. Our exploration teams completed widespread reconnaissance rock chip sampling, geological mapping and detailed, grid-based, geochemical soil sampling programmes.
By December 2012 more than 5,000 soil samples and more than 2,000 rock samples had been collected on the New Britain project. Mapping by our geological field team located significant copper mineralisation at a number of new locations where mineralisation had not previously been recorded. Subsequent fieldwork focused on the delineation of potential drill target areas. During 2013 three holes were drilled on geophysics targets in the Mt Nakru area, two at Junction and one at the Flying Fox target.
Background to the drilling programme at Tripela
Geological mapping and sampling in 2012 discovered significant copper and molybdenum soil anomalism at Tripela in the Mt Nakru area. Float and outcrop sampling and geological mapping delineated numerous occurrences of in situ high grade copper and molybdenum mineralization with grades up to 29.5% copper returned from outcrop assays. Much of the mineralization in outcrop is interpreted as D veins occurring around the alteration halo of a buried porphyry deposit. This geological mapping and rock sampling were followed up with trenching in 2013 and 2014 to more fully define the surface anomalies.
Tripela Drilling – Phase 1
The initial drilling programme at Tripela completed between January and May 2014 was designed to test for confirmatory evidence of underlying porphyry emplacement. The principal aim was the recognition of the zonation of argillic, phyllic and propylitic alteration at Tripela that would lead us to an inner potassic alteration zone which is in turn believed to be at the core of the porphyry deposit. DDH010, the last of seven drillholes completed during the initial phase of drilling, was completed in May and we then collated and assessed the data obtained from the seven drillholes. Widespread phyllic and argillic alteration was recognized in most of the holes, in particular DDH004, DDH006 and DDH008.
Current Tripela Drilling – Phase 2
In June 2014 we commenced a follow-up programme to test for the deeper porphyry bodies interpreted from the shallower vector drilling programme. The first deep hole, DDH012, was completed in early-August 2014.
By January 2015 we had completed four additional deep (each >950 metre) holes. Extensive epidote alteration, intersected in each of these holes, has allowed us to start to define an inner propylitic alteration halo. Petrographic work on samples from the hole confirmed the host rock as a dioritic porphyry intrusion. By the end of the first quarter of 2015 approximately 7,000 metres had been drilled at Tripela.
Dr. Greg Corbett and Doug Menzies of CMC Consulting Pty Limited (“CMC”) visited our project in PNG between 23rd June and 31st June 2014. The visit included some three days of core logging alongside our technical team and proved very helpful in terms of the development of our geological model for the project. The resulting CMC report has informed and validated the thrust of our exploration programme at Tripela and its objectives.
The Junction Target
Our initial drilling programme at Junction, carried out in mid-2013, comprised two holes of 841 metres and 736 metres depth respectively. These two diamond drillholes were directed at a strong combined chargeability and conductivity geophysical anomaly – a shallower chargeability anomaly which enclosed a deeper conductivity anomaly. While neither hole intersected economic grades or thickness of copper mineralization, important positive indicators of proximity to porphyry systems were observed in each. These indicators do point to the presence of a copper porphyry system at Junction, but possibly at a depth of up to 1,500 metres. The very extensive and intense silica-sericite-pyrite (“Phyllic”) alteration and the exceptionally well-developed pebble dykes which are seen in those two holes are diagnostic of such systems.