Wavenet completes surface geochemical sampling at Sintang, Selaup

By Ruli Setiawan

ASX listed exploration company Wavenet International Limited recently stated it has completed surface geochemical sampling of both Sintang in Sintang Regency and the 80 percent owned Selaup Gold Project in Kapuas Hulu, West Kalimantan.

The geological setting of the Sintang Project area, located some 250 km east of Pontianak, revealed extensive and high grade mineralisation indication, in addition to reveal an excellent indications of polymetallic mineralisation from the so far completed exploration work.

The company stated in its June 2012 quarterly report that the Sintang mineralization style is dominated by high grade gold and silver, accompanied by significant copper and lead within structures penetrating tonalities, andesites and sediments associated with cillicification, hydrothermal alteration and breccies.

A preliminary geochemical survey using a 400m grid has been conducted over the entire concession. This was completed in order to assess the distribution of gold and other metals throughout this large tenement and to assist in defining target areas for drilling.

The samples were assayed for a range of elements including gold, silver, copper, lead, zinc, arsenic and barium. The results showed a strong geochemical response for gold, silver, copper, lead and zinc while the pathfinder elements arsenic and barium were also well distributed. Assay values for gold-in-soil ranged up to1.68 ppm Au (equivalent to grams per tonne) and silver up to 3.5 ppm Ag. Copper ranged to 58.1 ppm Cu, lead up to 110.6 ppm Pb and zinc to 171.9 ppm Zn.

The gold anomalies are distributed in a general E-W orientation in at least three different bands. Copper distribution appears to be mutually exclusive with gold. Silver and gold anomalies are generally coincident and lead appears to mainly occur close to the copper anomalies.

Arsenic distribution was widespread but with generally low values peaking at 46 ppm As, indicating that the mineralisation is generally not arsenic-rich. The barium values were also generally low with a maximum of 382.4 ppm Ba. The distribution of barium appears to be similar to copper and may reflect the influence of hot fluids from nearby igneous intrusions and is more localised than the gold and silver.

The Selaup Project

Situated approximately 50 km south-west of Putussibau, in the Kapuas Hulu district of northern part of West Kalimantan Province, The geological reconnaissance work indicates that the Tertiary Mandai Group (sandstones and mudstones) are host to oxide and primary gold mineralization. This is thought to have been emplaced through hydrothermal solutions originating from the suite of Sintang Intrusives (mainly granodiorite, diorite and andesite stocks and sills) as the primary heat source. Indications are that this mineralization is extensive. From initial exploration work it appears that there are also polymetallic suiphide ores present on the concession. It is therefore expected that the mineralization of the workings could bear copper, lead and zinc as well as gold and silver. There are several shafts and adits into the hillsides and several sub-horizontal veins are being mined by artisans.

Gold is extracted using primitive methods such as mercury amalgam within small rotating drums containing coarsely crushed aggregate. Although other metals appear to be present in the ore it appears that these metals are not being extracted.

The Selaup mineralization style is dominated by high grade gold and silver accompanied by significant copper and lead within pelitic to arenaceous sediments and tufts associated with widespread silicification and hydrothermal alteration.

There is significant potential for hosting a world-class gold deposit at Putussibau since all the elements of a classic sediment-hosted large mineral deposit are present. There is widespread hydrothermal alteration (introducing carbonate and silica) of the sediments. The tenement covers the thermal aureoles of several intrusive diorite or granodiorite bodies. Individual veins show high metal grades. Brecciated sediment horizons and vein structures confirm a complex mineralization history.Regional structures such as the Singtang Intrusives, multiple diorite intrusions, faults and fracture zones confirm a strong, active deformational environment conducive to forming mineral deposits.

Putussibau Project

The company stated that permission to access the Putussibau 500 hectare polymetallic concession is still under application through the Indonesian Government Forestry Department. This area is known as Production Forest and a land disturbance (?borrow-use forest?) permit must be issued before drilling can take place.

Editing by Er Audy Zandri