PT. Fattah Minerals has completed regional geology mapping and geochemical sampling. As a result from this program, company has confirmed existing prospect that recognize from earlier sampling and mapping, also from desk study of exploration result of previous company. The best result of 35 sampling program carried out January-march 2012 as a follow up regional sampling conducted last year is 13,8gr/t Au, 15,5gr/t Ag, 183ppm Mo and also geological mapping program success to indentified a new vein with large alteration zone trending north west.
The completed results of sampling are:
PROPERTY DESCRIPTION AND LOCATION
The Block Project lies in Moyo Hilir and Lopok Sub District, Sumbawa District West Nusa Tenggara. It is centered at Latitude 117° 30′ 58,5″S and Longitude 8° 33′ 24,5″W. Moyo Hilir Block a total area of approximately 5.046 hectares. The project is situated approximately 200 kilometers east of the capital city of West Nusa Tenggara Province and approximately 20 kilometers, east of capital city of Sumbawa district and view kilometers from the North Coast.
Block Location and Accessibility of West Nusa Tenggara
Regional and Local Geology
The islands of Lombok and Sumbawa are part of the lesser Sunda Islands or Nusa Tenggara. These islands are situated on the western extension of the Banda Arc.
The stratigraphy of the two islands is roughly equivalent (Figure 7). The oldest rocks are generally a thick pile of andesitic pyroclastics, flows and intermediate intrusives with minor shallow marine sediments and limestones. Foraminifera in the sediments indicate a Miocene age. The older rocks are regionally metamorphosed to low grade greenschist facies.
A thin veneer of dacitic pyroclastics with associated diatreme breccias locally, overlies the Tertiary sequence. A thick blanket of epiclastics is exposed along the southern coast of Sumbawa and locally on south Lombok. The epiclastics are probably derived from the Miocene volcanic arc, but appear to have escaped the regional metamorphism seen inland.
Tertiary intrusive rocks are common in the volcanic terrane. The shift from andesitic to dacitic volcanism during the Tertiary probably reflects differentiating phreato magmatic centres. Older intrusives are commonly diorites, while later intrusive stocks and dikes are quartz diorites and tonalites. The youngest intrusive phases are dacites which locally form diatreme – dome complexes.
Quaternary rocks in Nusa Tenggara consist of the products of more recent volcanism, and related erosion and sedimentation. The central plain, consisting of alluvium and recent ash cover, effectively separates the Tertiary and Quaternary volcanic provinces in Lombok, but is lacking in Sumbawa.
A strong conjugate system of WNW – NW and NE faults are the dominant structural feature on both islands. The structures are probably related to north directed compression along the Miocene volcanic arc. Intrusive are preferentially emplaced along the NE structures (Figure 8 and 9).
A prominent NE transform running between Sumbawa Besar and Lunyuk forms a major discontinuity with a 10 km sinistral strike slip displacement.
Miocene volcanic centers west of the structure are aligned W and to a NE while those in the east are aligned approximately east – west.
West Nusa Tenggara Regional Geology (N. Suratno1995)
West Nusa Tenggara Magnetics Reduce To Pole compilation
Kakiang is geographically lays in 117° 32′ 56″Long / 8″ 32° 0″ Lat. Generally the bedrock consists of undifferentiated intermediate volcanic rocks (andesites). More felsic units, including dacite domes, in addition to the andesite volcanics, are recognized farther south in the area of Kakiang mineralization. At the north dominantly by tuffaceous sediment and lapilli tuff weakly altered. Fine grain tuffaceous sediment and lapilli tuff shows well associated with prophillytic alteration, abundant of pyrite observed in boulders and residual silica.
Moyo Hilir is geographically lays in 117° 32′ 13″ Long / 8° 34′ 27″ Lat . Geology of this prospect consist of tuffaceous andesite lava correlated with old volcanic rock unit, tuff that perceived to vary between crystal tuff, laplilli to rhyolite tuff, also locally lava sedimet. Some diorite also occurs. Lava and tuffaceous rock is locally prophyllitic altered (chlorite-epidote-calcite), argillic (kaolin-illite-smectite) and advanced argillic (quartz-pirophyllic). Mineralization found at prospect commonly pyrites, quartz veining, gipsum and rarely chalcopyrite and malachite.
Munung geographically lays in 117° 13′ 0″ Long / 8° 33′ 29 ” Lat (Figure 10, 11). The area is composed of intercalated andesitic flows, andesitic volcanic breccias and minor intercalated bedded ash tuff and clastic limestone. The presence of synsedimentary euhedral pyrite indicates a reduced environment when the clastic limestones deposited.
The pyroclastics rocks are generally andesitic composition which range from crystal ash-lithic tuff to lappili in places. This unit occurs within the central section of the prospect and appears to host most of the mineralization in the area. Further to the west of the area are covered by tufaceous limestone.
ALTERATION AND MINERALIZATION
Mineralization occurs in clay-silica structure showing open-space filling textures, including colloform banding, comb structure, and crustification. Alteration associated with a low-sulphidation epithermal system. Narrow veins and silicification are haloal by surrounding argillic and propyllitic alteration zones within the thick sequence of andesitic volcanics. Gold mineralization was accompanied by pyrite (Fe) with minor chalcopyrite (Cu). These sulphide minerals have subsequently been oxidized and partially mined by local and to date is already leaved by miners because the result not good enough.
Topography of IUP Area
Geology, Alteration and Mineralization
Rock alteration and associated gold-silver mineralization at Kakiang is defined as a low-sulphidation epithermal system. Anomalous to ore gold and silver grades are commonly associated within minor and tight, silica+sulphides veins with localized stockworks that are generally enveloped by clay+silica alteration assemblages.
Argilic alteration with strongly widespread of clay -silica-pyrite zones and associated with mm sized of quartz-limonite stockwork exposed in the south of these area nearby to Moyo Hilir.
Moyo Hilir Anomaly was first indentified within four main anomaly, up to 3.4 ppm Au from stream sediment 80 mesh. Follow up work succeed delineate anomaly 1 km square coincidence with strongly altered silica-kaolin. Early mapping conform clay-silica alteration in 1 x 1.4 km dimension and extend of clay alteration wider to north.
Geological mapping in the area was confined to the two rivers at Munung. Poor outcrop of andesitic tuff, limestone and sedimentary breccia were recognized, but with no evidence of any mineralization. However large silicified boulders are common place throughout the drainage areas, probably being the source of the anomaly.
Totally 645 rock samples was taken during the period of regional and advanced exploration by Rio Tinto sampling programme till late 1998 at this region (surface samples).
Regional exploration work, in the form of Stream Sediment assay analysis and rock chip sampling provided geochemical database which is use as pathfinder an anomalous area within the IUP block.
Established of background value of the anomaly was calculate from geochemical result of previous work PT. NNT and combine with Rio Tinto exploration result and other previous work of the area.
Newmont’s geochemical sampling program in the surrounding block in late 1990 identify a single catchments was anomalous in BLEG (Senggoro area), the 80 mesh and the panned concentrate sampling methods returning values of 6.91 ppb Au, 30 ppb Au and 1.58 ppm Au respectively.
Rock chip results were anomalous in silver. A single outcrop returned the following assays 0.36 g/t Au, 120 g/t Ag, 0.20 g/t Au, 185 g/t Ag, and 0.61 g/t Au, 105 g/t Ag.
The result of regional and advanced exploration sampling to localize the Prospect area area as seen on bleg, stream sediment and rock map of the IUP area as follow:
2. Moyo Hilir
Most of the anomaly from mid assay gold and silver with coincidence high arsenic is identified at Kakiang. Some of mid value also detected at Moyo Hilir.
Additional sampling program was conducted at November 2011 collected 23 rock samples, mostly taken from silisified tuff and quartz-silica-clay outcrop return with encouraging result e.g. 2.04 ppm Au, 2.3 ppm Auand 1.7 ppm Au, a systematic sampling program has made as follow up of these result and planned to run at this early year.
In 1992 to 1997, previous exploration work by Rio Tinto defined an anomalous association of Au-Ag-Cu-Pb-Zn in -80 stream sediment samples from north and west of Pantan River. 3 stream sediment samples (silt and bleg) was collected and some returned midly anomalous stream sediment values, with -80 Au values up to 0,38 ppm, 3ppm Ag, 127ppm As, and 1012ppm Zn from tributary of Pantan River .
Geochemistry assayed result returned show low notation, where sample of moderate anomalous gold zone taken from quartz veins in the stockwork zone. highest value assayed returned less than 0,1 ppm Au from grab sampling
This Prospect located approximately 2 km South of Kakiang. Several sample taken from creek was assayed up to 2 ppm Au. Grid soil sampling (Rio Tinto) failed to trace gold mineralization in region.
Minor base metal sulphides, occur in rare quartz veins associated with a broad zone of weakly clay-silica altered fine grain tuff at Moyo Hilir. The argillic altered zone covers an area of approximately 300 X 600 meters. Stream sediment samples collected immediately down stream of the altered area returned high BLEG values (ie. 111 ppb Au/ 132 ppm Ag), and are interpreted to reflect low Au concentrations over a abroad area.
Totally 22 rock chip samples have been collected from the area by Rio Tinto. Most samples have been of the rare quartz veined and silicified material. The result is quitly encouraging with the best is a value of 0.48 g/t Au and 418ppm As, but the remainder returned values generally less than 0.2 g/t Au.
Anomolous area Within the Block (Kakiang, Moyo Hilir, Munung)
Extensive exploration has been conducted from 1986 to 1998 (Newmont and Rio Tinto) in the region. This work included geological, geochemical and geophysical surveys.
Descriptions of gangue and ore minerals, historical and independent gold and silver grades, as well as the regional and local geology, style of structures and their continuity along strike indicates that the area which contains the Kakiang, Moyo Hilir and Munung and areas as far North West as the pungkit area concessions (PT Antam) and South East as the Lape area cover a gold bearing low sulphidation epithermal system- It is part of a belt of similar mineralized zones and deposits associated with a suture zone and transform fault which lies in the centre of the Sumbawa Island.