 584 sq km license parts of which explored since 1960s
Central 20 km by 6 km plateau dwarfs better-known 7
by 2 km Wowo plateau
Better apparent grade and topography than
Ramu project under development
Linked to Oro Bay by gravel and sealed road
1960-71, 240 auger holes, 56 pits, 1 costean
1999 Anaconda estimates in 158 sq km section 630mt
at 0.78% and 200mt at 1.01%, in saprolitic layer
The laterite bearing nickel potential of the Mambare Plateau, some
2 to 20 kilometres north of Kokoda has been explored intermittently
since 1960. Kokoda and Mamba Estate to the southwest of Mambare
Plateau are linked to Popondetta and Oro Bay by gravel at first and
sealed road. The Company through a local 75% owned subsidiary holds
the exploration rights to Mambare Plateau within EL 1390, which was
granted over 584 sq km for a 2 year period on June 10, 2005.
The Mambare Plateau is an elevated 20 by 7 kilometre old land surface west of
the Ajule-Kajale Range, developed on tectonite ultramafics. To the east, these
ultramafics are overlain by gabbroic rocks and submarine basaltic volcanics.
Previous exploration was conducted by several companies in the 1960's, including
the Bureau of Mineral Resources, Homestake-Hanna Syndicate, Amax Mining
(Australia) Inc., Southern Mining & Development Co. Ltd. and PNG Nickel Ltd.
Exploration consisted of pitting and hand augering with at least one bulldozer
trench being dug. Between 1960 and 1971, 240 Auger holes were drilled, and 56
pits and one costean dug. In 1999 Anaconda Nickel Ltd reviewed the data over a
158 sq km area of the Mambare Plateau and estimated two limonite resource
potentials: 630 Mt at 0.78% nickel with a 0.5% cut-off and 200 Mt at 1.01%
nickel with a 0.8% cut-off.
The auger drilling across the Mambare Plateau indicates a profile of:
3-5m of ash
3-6m of low grade limonite laterite;
3-6m of limonite ore grading 0.9 to 1.1% nickel (+0.1% cobalt); and
4m of saprolite ore grading at least 1.15% nickel
The pits on the Arumu Slopes indicate a similar profile of:
3-6m of ash
0-2m of low grade limonite laterite
4m limonite ore; and
4m of saprolite ore
This profile is best illustrated by pit KR 022 which has a profile of;
3m of ash
3.66m of limonite ore grading 1.05% nickel (and 0.12% cobalt)
4.55m of saprolite ore grading 1.25% nickel
The current programme consisted of creating a data base of the historical data
with ground truthing. The line of pits sunk along the Ukita Ridge in 1962 were
located, surveyed into the AMG 66 grid using a GPS and re-sampled. The pits on
Namara - Karati Ridge were located and surveyed into the AMG 66 grid. Several
of the pits dug by Amax from the 1968 programme on the southern slopes of the
Mambare Plateau were also located and surveyed into the AMG 66 grid.
This surveying has allowed correction of the calculated co-ordinates of the pits
and the auger holes so they are properly plotted on the published topographic
base with the AMG 66 grid.
The samples from the ten re-sampled shallow pits were assayed in Djakarta by PT
Intertek Utama Services using the XRF technique. Elements assayed include
nickel, cobalt along with Al203, CaO, Cr2O3, Fe2O3, K2O, MgO, MnO, Na2O, P2O5,
TiO2 & LOI. There was good correlation with previous results, with 19 of the 48
samples grading over 0.8% nickel and 11 grading over 1% nickel.
A ground magnetometer traverse was completed up the Arumu Slopes onto the
Mambare Plateau over a distance of 3300 metres, with individual readings every
25metres.
Seven helipads were cleared to afford helicopter access in the near future.
The 1971 sampling, and that carried out this season, tested systematically for
cobalt and the data indicate that over 500 ppm Co is very common in the
mineralized limonite sections, with one re-sampled hole grading 0.12%.
Compilation by Anaconda indicates that the Plateau and its slopes have the
potential to host +200 Mt of limonite ore grading 1% nickel. To this resource
the cobalt potential of approximately 0.1% can also be added. The auger
drilling and pitting did not intersect much of the underlying and generally
higher grade saprolite ore. This resource potential may be similar to that of
the limonite ore and can also be added to the potential indicated by Anaconda.
This resource potential can be summarised as:
Limonite Ore 200 Mt of 1% nickel and 0.1% cobalt and
Saprolite Ore 200 Mt of 1.25-1.5% nickel
Much of the previous auger drilling and pitting were too shallow to test
adequately the limonite ore, and in many cases failed to encounter the saprolite
ore or ended in mineralization. The potential resource needs to be further
evaluated with diamond drilling to test both this limonite ore and the
underlying poorly tested saprolite ore. The underlying saprolite ore is
suggested to be as thick as the overlying limonite ore. Geophysical techniques
such as magnetics and ground penetrating radar may help better definition of
bedrock rock types and thickness of laterite profiles.
The large size of the 20 km by 5-7 km Mambare Plateau, compared with the 7 km by
2-3 km envelope of known mineralization at the nearby Wowo Gap, gives a large
potential area of mineralization and the possibility of a significant resource.
Based on an independent
geological report prepared by Baxter Geological
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