Copper potential of KSK COW - Kalimantan Gold Corporation Limited

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Introduction
At the request of Mr Rahman Connelly of Kalimantan Gold Corporation Limited, the
author spent 4 days in Palangkaraya, Kalimantan reviewing the results of recent
exploration within the P.T. Kalimantan Surya Kencana Contract of Work (KSK
COW; Figs 1 and 2). The aim of this work was to evaluate the copper potential of the
COW following the 2007 exploration program conducted by Oxiana Limited in joint
venture with Kalimantan Gold Corporation Limited.
Approach
Oxiana Limited undertook an exploration program within the KSK COW in 2007
with a target of +300 million tonnes at 1% Cu. The exploration program involved
geological mapping, re-logging of drill core and reprocessing of geophysical and
geochemical data as well as drilling 16 new diamond drill holes in the Beruang
Kanan, Beruang Tengah, Baroi and Mansur prospects. The drill holes mostly returned
low grades of copper and gold and Oxiana subsequently withdrew from the joint
venture. The current review considered the Oxiana Limited data as well as previous
exploration data on these four prospects in order to assess their copper potential. In
addition, the copper potential of the Tumbang Huoi prospect is also briefly
considered.
Geological setting
The KSK COW is situated within the mid-Tertiary Kalimantan volcanic arc that hosts
a number of porphyry copper-gold deposits and prospects including Mamut, Rina,
Manto-Tebihi and those within the KSK COW. In addition, several low sulphidation
epithermal deposits are present including Kelian, Indo Muro, Masuparia, Gunung Mas
and Jelai-Mewet.
Porphyry copper-gold mineralization in the KSK COW is associated with a number of
probable Oligocene age intrusions that were emplaced at the junction between
Mesozoic metamorphic rocks to the south and accreted Lower Tertiary sediments to
the north (Geiger and Prasetyo, 2004). Structures in the region are dominated by
northeast-striking faults that are interpreted to be arc parallel or accretionary faults
(Geiger and Prasetyo, 2004). Subsidiary northwest-trending arc normal or transfer
faults cross-cut the northeast structures and the intrusions have commonly been
emplaced within dilational settings at the intersections of these major structural
features (Geiger and Prasetyo, 2004).
Large circular features that are evident on satellite images commonly coincide with
the mid-Tertiary intrusions and are interpreted to be volcanic collapse features (Geiger
and Prasetyo, 2004). These host many of the porphyry prospects within the KSK
COW.
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Peter J. Pollard
Copper potential of KSK COW, Central Kalimantan