Gold mining in Atjeh

Properties2
tagsconcept, mining, gold, precolonial, colonial, event, atjeh, exploration, silver, mineral-resource
aliasesAtjeh gold, Acheh gold mining, gold washing in Atjeh, Atjehnese goldfields, Gold exploration in Atjeh, Atjeh gold explorations, Atjeh gold survey, Gold in Atjeh, Gold-silver in Atjeh, Atjeh gold-silver deposits

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Ancient workings and the renown of Atjehnese gold

In historical times a notable gold industry was found in the mountains of Acheh, and the former landschap of Kawaj XII is said to have owed its origin to it. In the upper Wojla area extensive mine workings of great depth survived, probably driven by Hindus in former times — a subject treated by Veltman in his article “Gold Exploitation in Atjeh” (1906). The fame of this wealth was such that the region was at one time identified with the biblical gold land of Salomo.

Native gold-washing

By the early twentieth century the population was no longer able to undertake works on the old scale, and the surviving native exploitation consisted only of washing gold dust from river silt, chiefly in Langö, the upper Meureudu and the upper Reuengeuas areas. The work was done mainly by women, for whom it provided a small income. Its output escaped all measurement, since the gold dust was destined exclusively for the goldsmiths of the west coast.

Colonial prospecting

The gold wealth of the upper Wojla district prompted a mining investigation by the engineer Janssen in 1904, who reported unfavourably on its prospects. The later surveys by the section of the Mining Service established in Acheh returned results rather more favourable than those earlier findings had suggested. Gold was known across many parts of the region: the west coast took precedence — Wojla, Seunagan, Boenin and Ong Taloë — but the metal had also been established in the Gajo land (upper Gajo Löes, upper Djamboe Ajë and the upper Alas river) and on its eastern and northern side at Peusangan and Semedi. Whether exploration would lead to systematic mining remained an open question.

Coal and the wider Mining Service survey

Coal too appeared to occur in Acheh in workable quantities. It had been thought that only brown coal was present — extensive but of too young a formation to be exploitable — but the Mining Service’s recent investigations had also brought to light coal of good quality, notably on the north coast, whose workability was to be examined further. These findings were part of a systematic geological and mineralogical survey to which the Mining Service had lately devoted great effort, employing no fewer than three mining engineers (geologists) permanently in the region.

Significance

Gold in Acheh marks the distance between the region’s storied past and its colonial present: once renowned enough to be confused with the gold land of Salomo and worked by deep mountain galleries, it had dwindled to women panning river silt for the west-coast goldsmiths. The cautiously hopeful re-survey of the deposits by the Mining Service belonged to the same colonial drive to inventory and exploit Acheh’s mineral wealth that had opened the oilfields of the east coast.

Account from The Geology of Indonesia (1949) — Atjeh gold exploration (1922, 1946)

The 1922 Jansen-Lindberg-Wolvekamp survey

The 1922 survey of Jansen, Lindberg and Wolvekamp is the most ambitious single mineralogical survey of Atjeh undertaken during the colonial period. For the primary gold deposits, the survey took 35 samples from quartz-veins in the pre-tertiary slate-formation of the Atjeh interior, of which only two yielded positive assays: one from the river basin of the S. Assai (11 gr Au/ton) and one from the S. Meranging (10.8 gr Au/ton). The upper-Assai region was recommended “for a more detailed investigation”. For the secondary (alluvial) gold deposits, the survey noted the presence of “many old workings, as well in gold-bearing tertiary conglomerates as in alluvial river deposits downstream of these” on the West coast of Atjeh.

For the full account of the Jansen-Lindberg-Wolvekamp survey, see the entries on P. J. J. Jansen and S. Assai.

The 1946 De Groot report

The 1946 report by De Groot is, with the 1922 Jansen-Lindberg-Wolvekamp survey, one of only two printed colonial sources on the Atjeh gold placers. De Groot’s principal contribution is the favourable opinion that “the placers of the Meulaboh areas offer good prospects for the winning of gold and platinum” — a judgment that post-dates, and partly reverses, the more cautious tone of the 1922 survey. De Groot’s report also documents the M.A.E.M. dredging operation on the Geudong Concession (1940–1941) and the observation that the M.A.E.M. dredges were gaining mercury with each clean-up — the documentary evidence that the West-Atjeh alluvial deposits contain native mercury and cinnabar in addition to gold and platinum.

For the full account of the De Groot report, see the entries on C. de Groot and Basin of Meulaboh.

The M.A.E.M. Geudong Concession production (1940–1941)

The only recorded colonial-era gold production on Atjeh territory is the M.A.E.M. operation on the Geudong Concession in the Meulaboh coastal basin. Production started in 1940 with two bucket dredges (buckets of 6 cubic feet) with a joint capacity of 270,000 cubic yards per month, and the operation continued into 1941 until it was suspended by the Pacific War and the 1942 Japanese invasion. The M.A.E.M. operation also produced platinum as a byproduct (“some kilograms per month”) — the only recorded colonial-era platinum production on Atjeh territory.

For the full account of the M.A.E.M. operation, see the entries on M.A.E.M. and Geudong Concession.

The Sumatran gold-silver belt: Atjeh-to-Benkulen

The Atjeh gold exploration is part of the wider Sumatran gold-silver belt, which Van Bemmelen (citing Hövig 1914 and Tobler) describes as extending “from the most northern point of Atjeh to the most southern point of Benkulen” — a continuous mineral province of nearly 1,600 km in length. The Atjeh occurrences (the S. Assai and S. Meranging quartz-veins, the Meulaboh placers, the West-Atjeh alluvial deposits) take their place as the northern terminus of this belt, and the colonial-era exploration of Atjeh gold is accordingly part of the wider colonial-era exploration of the Sumatran gold-silver belt that began with the 1895/1896 discovery of the Lebong Donok gold-bearing quartz outcrop near Muara Aman in Benkulen.

Significance

The Atjeh gold exploration is significant for the encyclopedia of Acheh history because the 1922 Jansen-Lindberg-Wolvekamp survey and the 1946 De Groot report together constitute the entire printed colonial basis for the assessment of Atjeh’s gold potential. The 1940–1941 M.A.E.M. operation on the Geudong Concession is the only recorded colonial-era gold production on Atjeh territory, and the platinum byproduct of the M.A.E.M. operation is the only recorded colonial-era platinum production on Atjeh territory. The Atjeh gold exploration is also part of the wider Sumatran gold-silver belt — the continuous mineral province that extends from Atjeh in the north to Benkulen in the south — and the colonial-era exploration of Atjeh gold is accordingly part of the wider colonial-era exploration of the Sumatran gold-silver belt.

Account from The Geology of Indonesia (1949) — Gold and silver in Atjeh

The Sumatran gold-silver belt

Van Bemmelen, citing Hövig (1914) and Tobler, describes the Sumatran gold-silver mineral province as extending “from the most northern point of Atjeh to the most southern point of Benkulen including the adjoining part of the Lampong Districts”. The total length of the belt is nearly 1,600 km in Sumatra (out of nearly 4,000 km for the wider metalliferous belt that extends through Java and the Lesser Sunda Islands up to Alor), with a maximum width of about 100 km. The Atjeh occurrences — the S. Assai and S. Meranging quartz-veins, the Meulaboh placers, the West-Atjeh alluvial deposits — accordingly take their place as the northern terminus of this belt.

The belt’s primary deposits are of two types:

  • Gold-bearing quartz veins in the pre-tertiary Slate-formation, limited to the contact zones of the pre-tertiary granites (according to Tobler). The S. Assai and S. Meranging quartz-veins belong to this type.
  • Young gold-silver veins in tertiary and younger rocks, often with high silver-to-gold ratios and accompanied by Cu, Pb and Zn minerals.

The belt’s secondary (alluvial) deposits are the placers of the West-Atjeh coast, where the gold-bearing black sands of the Meulaboh coastal basin contain, in addition to gold, fine grains of cinnabar and considerable amounts of platinum.

The 1922 Jansen-Lindberg-Wolvekamp primary-gold survey

The 1922 survey of Jansen, Lindberg and Wolvekamp is the most ambitious single mineralogical survey of Atjeh undertaken during the colonial period. For the primary gold deposits, the survey took 35 samples from quartz-veins in the pre-tertiary slate-formation of the Atjeh interior, of which only two yielded positive assays:

The upper-Assai region was recommended “for a more detailed investigation” — the only positive prospecting recommendation for an Atjeh primary-gold occurrence in the colonial geological literature. For the full account of the 1922 survey see the entry on P. J. J. Jansen.

The West-Atjeh alluvial deposits

The West coast of Atjeh shows “many old workings, as well in gold-bearing tertiary conglomerates as in alluvial river deposits downstream of these”. The alluvial gold of the West-Atjeh coast is found in the pleistocene river terraces of the Meulaboh coastal basin, where it is accompanied by platinum and cinnabar. Van Bemmelen’s description of the West-Atjeh alluvial gold reads:

“The alluvial gold at sites of second-, third-, or higher order of displacement is found in the river terraces between the central mountains and the alluvial lowland. The gold grains are coarse near the mountain border, becoming smaller downstream. The gold-bearing black sands contain fine grains of cinnabar, besides considerable amounts of platinum.”

The terrace deposits are from ten to a hundred feet thick, and “remains of these terraces, in so far as they have not yet been worked by the natives, often proved to be very rich”. The primary sites of the gold “have to be sought in the pre-tertiary Old Slates Formation and granite contacts of the interior”, but “due to the outbreak of the war these primary deposits have not yet been explored.”

The 1946 De Groot report

The 1946 report by De Groot is, with the 1922 Jansen-Lindberg-Wolvekamp survey, one of only two printed colonial sources on the Atjeh gold placers. De Groot’s principal contribution is the favourable opinion that “the placers of the Meulaboh areas offer good prospects for the winning of gold and platinum” — a judgment that post-dates, and partly reverses, the more cautious tone of the 1922 survey. De Groot’s report also documents the M.A.E.M. dredging operation on the Geudong Concession (1940–1941) and the observation that the M.A.E.M. dredges were gaining mercury with each clean-up — the documentary evidence that the West-Atjeh alluvial deposits contain native mercury and cinnabar in addition to gold and platinum. For the full account see the entries on C. de Groot and Mercury in Atjeh.

The M.A.E.M. Geudong Concession production (1940-1941)

The only recorded colonial-era gold production on Atjeh territory is the M.A.E.M. operation on the Geudong Concession in the Meulaboh coastal basin. Production started in 1940 with two bucket dredges (buckets of 6 cubic feet) with a joint capacity of 270,000 cubic yards per month. The deposit contained 55–60 % boulders (the largest of which “could just be handled”) and 40–45 % fine material. There were two types of gold: fine gold with somewhat higher silver content, which was easily amalgamated, and coarse gold with lower silver content, which was difficult to amalgamate. The platinum production was some kilograms per month. Treatment was by amalgamation and Wilfley tables. For the full account see the entries on M.A.E.M. and Geudong Concession.

Significance

The Gold and silver in Atjeh is significant for the encyclopedia of Acheh history because it is the corpus of colonial-era geological observations and mining attempts that document the occurrence of gold (and accompanying silver, platinum and mercury) in the Residency of Atjeh — the northern terminus of the Sumatran gold-silver belt. The 1940–1941 M.A.E.M. operation on the Geudong Concession is the only recorded colonial-era gold production on Atjeh territory, and the platinum byproduct of the M.A.E.M. operation is the only recorded colonial-era platinum production on Atjeh territory. The De Groot 1946 observation of native mercury and cinnabar in the West-Atjeh alluvial deposits is the only documented colonial-era observation of mercury minerals on Atjeh territory. The Atjeh gold record is, in this sense, the principal mineral-economic achievement of the colonial period in Atjeh: the only Atjeh mineral resource that was actually translated into industrial production, however briefly, before the Pacific War and the Japanese occupation brought the colonial mining industry to an end.

See Also

Source

De Europeesche Industrie [“The European Industry”], section De Buitenbezittingen (“The Outer Possessions”), in Grooten van Zee en Land in Nederlandsch-Indië, Vol. 6, pp. 250–251 (English translation from the Dutch).

Veltman, “Goudontginning in Atjeh” [“Gold Exploitation in Atjeh”], in T.K.N.A.G. (1906), V. — cited in the source.

C. Snouck Hurgronje, Het Gajo-land en zijne bewoners, p. 361 — cited in the source.

The Geology of Indonesia, by R. W. van Bemmelen, Vol. II: Economic Geology (The Hague: Government Printing Office; Martinus Nijhoff, 1949), pp. 105–122 (gold and silver in Sumatra, including the Atjeh explorations of 1922 and 1946 and the M.A.E.M. Geudong Concession production).

The Geology of Indonesia, by R. W. van Bemmelen, Vol. II: Economic Geology (The Hague: Government Printing Office; Martinus Nijhoff, 1949), pp. 105–122 (gold and silver in Sumatra, including the Atjeh explorations and the M.A.E.M. Geudong Concession production).

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