Pelepah Kanan, Pelepah Kiri, Susor Rotan
Sn Fe W
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The Pelepah Kanan tin and iron deposit is located 14 km NNW of Kota Tinggi in Johor State, some 40 km NNE of Singapore (#Location: 1° 49' 43"N, 103° 50' 15"E).
There are references to mineralisation at Pelepah Kanan dating back to 1830, while a report to the Sultan of Johore in 1902 mentions the deposit and attendant mine workings. The main orebody was rediscovered in 1933 by Ishihara Sangyo Koshi. Prospecting continued until 1936 when the associated alluvial and colluvial tin deposits were found. Mining commenced after the Japanese Occupation of Malaya and continued until the end of the second world war when it was confiscated by the Custodian of Enemy Property. Following a successful bid for the property by a consortium of Pahang Consolidated, Sungei Besi and Anglo-Oriental, and the subsequent early withdrawal of the first two partners, Anglo-Malayan Development (AMD), a subsidiary of Anglo-Oriental, tested the area. They relinquished their claim to the property in 1949, while still retaining prospecting rights. In the same year, Woon Chow Kwai started mining the area and in 1957, on AMD's total withdrawal, gained title to the area under the name of Pelepah Kanan Mines Ltd. During the period 1957 to the present, the property has been the subject of negotiations and testing by a number of parties. In the meantime, Waterfall Mining continued to extract both tin and iron on a small scale.
The production to 1978 was of the order of 5 million tonnes of ore containing both tin and iron.
The Pelepah Kanan mine was visited in January 1978, including an underground inspection of the Gakak mine, and observations from the visit and discussions with geologists working on the deposit are included below.
See the separate East Coast Malaysia Tin Belt record.
Geology and Mineralisation
The Pelepah Kanan iron-tin body is located within a north-south elongates ovoid, 320 x 550 m roof pendant of Permian calc-silicates which are embraced by the Upper Permian to Lower Triassic (~222 Ma) Muntahak Granite. The mineralised pendant, which is underlain by granite at a depth of ~50 to 80 m, is connected to the SW by a neck to lithologically and structurally different shales and sandstones, probably separated along a faulted contact. The host sequence in the mine area is folded into a shallow SW plunging syncline with dips ranging up to 15° on the extremities of the limbs.
In the mine area, the deposit occurs as a hill in a relatively simple, shallowly dipping sequence comprising a lower unit of quartzite-calc-silicates, overlain by lightly weathered and decomposed calc-silicates, which are capped by a shallowly southward plunging massive magnetite-hematite-martite lens, containing coarse grained magnetite up to 6 cm across, and minor quartz, cassiterite and siderite. The magnetite-rich lens is connected downwards to a feeder zone to the west composed of magnetite-quartz-cassiterite-fluorite-loellingite-scheelite-sulphides (Yeap, 1982, 1984). To the east, a crescent shaped body of contorted, rhythmically banded developments of magnetite-fluorite-cassiterite ±loellingite ±quartz ("wrigglite") occurs, containing areas of overprinting green ferrohastingsitic amphibole and green annitic biotite (Kwak, 1987).
The calc-silicates are cut by numerous pegmatite and and quartz veins carrying K feldspar, cassiterite, arsenopyrite, pyrite, scheelite, chlorite and loellingite. Tin mineralisation occurs in both the feeder zone and in the magnetite-rich lens. The distribution of both cassiterite and magnetite are in intimate association with the calc-silicate alteration (Kwak, 1987).
In the calc-silicates, tin occurs within quartz-feldspar veins which are parallel to sub-parallel to the banding, and is to a large extent within finer veinlets. Mineralisation is also disseminated through the calc-silicates as very fine cassiterite of <100 µm. In the magnetite-rich lens, tin is apparently disseminated through the unit without any accompanying veining. The grade within the magnetite lens is, in general, around 0.4% Sn with patches up to 0.8%, while around 0.65% Sn is found within the calc-silicates.
The higher grade tin mineralisation follows the magnetite calc-silicate contact and diminishes towards the granite. The lower part of the calc-silicate unit carries levels of from 0.04 to 0.3% Sn throughout. This drop-off corresponds to the change in nature of the calc-silicates to a lighter, more siliceous, rock which is basically a quartzite. The higher grade band averages ~23 m in thickness and is developed over a length of ~280 m, and width of the order of 240 m in a NE-SW direction along the synclinal axis.
The main magnetite rich lens carries 55 to 60% Fe, 0.1 to 1.0% Sn, up to 1.07% SiO2, up to 1.02% Al2O3 and up to 0.35% Mn. Cassiterite occurs as fine crystals coating magnetite in vuggy areas (Kwak, 1987).
The unweathered calc-silicate is a very hard pale green rock which has an obvious, but not outstanding, banding. This banding is evident as colour variations from a pale green to a mid green (partly due to epidote in places), to dark chloritic bands. Individual bands range from 1 to 30 mm in thickness. Cutting the rock in some areas are a series of fractures in 2 to 3 directions, that are flanked by highly chloritic selvages up to 1 cm wide on either side of the fracture. Superimposed on these is an intricate series of multi directional hairline veinlets of a pale green material, similar to the pale green bands within the calc-silicates themselves. The veining within the calc-silicates occur parallel to sub parallel to the banding as a series of quartz-feldspar veins as described above. In quite a few instances, these veins appear to be parallel to the banding, but a significant proportion branch or are only parallel to banding in one plane, in general cutting bedding at around 5° to 10°. These veins have the appearance of being fracture fillings. In detail they range from 1 to 30 mm in thickness and comprise quartz with decomposed (weathered) pale feldspars from 1 to 7 mm across, making up around 30% of the vein. Cassiterite occurs as disseminations or single coarse crystals up to 2 mm across or as aggregates of coarse crystals up to 1 cm in diameter.
Irregular epidote patches are also found within the calc silicates, adding to the overall pattern.
Outcrops of the unweathered calc-silicate can be seen to grade laterally and vertically into the weathered variety. The latter comprises a pale, bleached, soft rock, grading to a soft white clayey material. It contains decomposed cassiterite bearing quartz veins. The fine veinlets seen in the fresh calc-silicates weather to a pale white clay. Some veins develop into limonite coatings while the more siliceous veins remain as hard pock-marked white quartz veins.
The magnetite layer is largely made up of well banded magnetite which is often coarsely crystalline. Individual laminae range from 3 to 10 mm in thickness, with massive magnetite bands up to 50 cm thick. In places the unit has been weathered to limonite and martite which enhances the fine banding. There are thin lenses of shale within the iron unit represented by mottled yellow to purplish clays. These lenses are up to 20 cm thick but usually less than 3 m long.
In places, the iron is vuggy. The thickness of the sequence from the granite to the original (or pre-mining) surface was of the order of 120 m.
The granite is a porphyritic biotitic variety with quartz and feldspar phenocrysts 3 to 5 mm across, set in a 2 to 3 mm quartz feldspar-biotite groundmass. In some places, aplitic phases of the same are found. Below the orebody the granite has a flat lying upper surface. On the south west slope of the open pit a sequence of inter-bedded sandstones and shales dips steeply to the west. This may be part of the quartzite sequence found immediately to the south west of the mine. This quartzite is a white to brown massive fine quartzite, in places with well bedded shaly beds from 1 to 2 cm thick within the quartzite.
To the north and south of the mine, two similar but smaller iron deposits are found above flat lying, metamorphosed argillaceous sediments which have an associated tin zone. These are Susor Rotan, some 2.5 km to the NNE, and Pelepah Kiri, 2.5 km to the south, of Pelepah Kanan respectively.
At Pelepah Kiri, tin mineralisation is disseminated through a magnetite unit, as at Pelepah Kanan, and occurs as mutually parallel lensoid units, which are parallel to, but below the iron horizon and within 'altered' argillaceous sediments. The form the tin takes in the sedimentary rocks is not known, although it is believed that veining of the type seen at Pelepah Kanan is absent. The ore zone occupies an area with dimensions of around 500 x 300 m with variable grades and thicknesses. The stratigraphic relationship between the individual tin-iron occurrences in the district is not known.
In 1957, Pelepah Kanan was evaluated to contain a remaining tonnage of 1 Mt of iron ore @ 0.8 % Sn and 2 Mt @ 55% Fe and 0.65 % Sn. The highest grade Sn blocks range from 2 to 16 % Sn02 (Yeap, E.B., 2000)
The most recent source geological information used to prepare this summary was dated: 2009.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
References to this deposit in the PGC Literature Collection:
Teh Guan Hoe and Lee Heng Poh 2003 - EPMA characterization of the Fe-Cu-Sn mineralisation at Waterfall Mine, Pelepah Kanan, Johor: in Geological Society of Malaysia, Bulletin 46 pp. 393-399|
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