Arc Exploration reports Indonesian mining ops

The following is an excerpt taken from Australian mining firm Arc Exploration Indonesian progress report released on Wednesday.

ARX is exploring for gold, silver and base metal deposits along Indonesia?s highly prospective magmatic arcs and associated terranes. The primary exploration targets are high-grade epithermal gold-silver veins and bulk tonnage porphyry-related copper-gold deposits.

Java

Trenggalek Project, East Java
The Company has a joint venture with P.T. Sumber Mineral Nusantara, which holds the Trenggalek Exploration IUP license covering an area of 30,044 ha (~300 km2) in the Southern Mountains of East Java.

The region has excellent potential for major gold-copper deposits, highlighted by the discovery of the Tumpangpitu porphyry copper-gold deposit by Intrepid Mines at their Tujuh Bukit Project.

Gold mineralisation at Trenggalek occurs in intermediate-sulphidation epithermal quartz vein systems associated with hydrothermal breccias and silica cappings in volcanic rocks and limestone. The IUP area is also prospective for replacement-style (?jasperoid?) gold and porphyry-related copper-gold mineralisation.

A high-resolution, aeromagnetic & radiometric survey was flown over the entire Trenggalek IUP tenement in the quarter and ground work was undertaken on the IUP in non-forestry areas whilst awaiting renewal of the forestry use permit (?Pinjam Pakai?) from the Indonesian Ministry of Forestry.

Exploration expenditure at Trenggalek during the quarter totalled A$39,816 (excluding expenditure by Anglo American in relation to high-resolution airborne magnetic and radiometric surveys and surface geochemical and geological surveys referred to below).

Agreement with Anglo American
The Company has entered into an agreement with Anglo American in respect of the Trenggalek Project.

Under the agreement Anglo American has fully funded the high-resolution airborne magnetic and radiometric survey over the entire IUP tenement and undertaken some surface geochemical and geological surveys in selected areas.

Following the completion of these surveys and evaluation of the results Anglo American may elect to move forward and earn a majority interest by sole funding ongoing activities at the Trenggalek Project.

The agreement provides a further opportunity to build a close working relationship with Anglo American in Indonesia.

Airborne Survey
A high-resolution, aeromagnetic & radiometric survey was flown over the entire Trenggalek IUP tenement in the quarter by Anglo American. It was flown using an MD500E helicopter with a stinger-mounted system. Data acquisition and processing were contracted to GPX Surveys P/L of Perth.

The survey was flown on 100-m spaced N-S oriented flight-lines and 1,000-m spaced E-W tie-lines at a nominal flight height of about 50-m above the ground surface. A total of 3,675 line-kms was flown. The primary objectives of the survey are to explore for large porphyry copper-gold and new epithermal gold-vein systems, and to determine future direction and targets within the Trenggalek IUP. The survey data was processed late in the quarter and is now being interpreted.

The geology of Trenggalek is similar to the Tujuh Bukit district in East Java, where Intrepid has discovered a large porphyry copper-gold system associated with distinctive magnetic features that were highlighted in a similar geophysical survey.

Sumber Bening
Sumber Bening lies on prominent north-northwest-trending structures that cut across a 4km diameter-circular feature on the western side of the IUP. It contains an extensive area (+2-km by 1-km) of silica-clay-pyrite alteration with localised pods of vughy silica alteration centred on volcaniclastic rocks and quartz-feldspar porphyry intrusions.

Soil sampling and detailed geological mapping at this prospect were completed late in the quarter. All samples have now been submitted to the laboratory and results are awaited. The target is a possible porphyry system lying beneath the extensive silica-clay alteration lithocap identified in this area.

Papua

Strategic Alliance ? Anglo American
The Company holds a 20% interest in a Strategic Alliance with Anglo American PLC (Anglo) to explore for copper-gold deposits in Papua and West Papua provinces. The Alliance currently holds three Exploration IUP tenements covering nearly 3,000 km2 at the centre of the Bird?s Head peninsula in West Papua Province which cover prospective ground in the region which also hosts Grasberg - Indonesia?s largest porphyry copper-gold deposit.

Anglo is responsible for managing and funding all exploration activities. No field work was undertaken by Anglo during the quarter. (end of excerpt)