Platinum in Atjeh is the colonial-era geological record of the occurrence of platinum as a byproduct of the alluvial gold mining of the West coast of Atjeh — a record that comprises the 1940–1941 M.A.E.M. dredging operation on the Geudong Concession in the Meulaboh coastal basin, which produced “some kilograms per month” of platinum as a byproduct of the gold-dredging. The M.A.E.M. operation is the only recorded colonial-era platinum production on Atjeh territory, and the West-Atjeh alluvial deposits are accordingly the only Atjeh locality for which platinum production figures are recorded.
Geological context
The platinum of the West-Atjeh alluvial deposits is geologically associated with the alluvial gold of the Meulaboh coastal basin. Van Bemmelen’s account of the Meulaboh placers records that “the gold-bearing black sands contain fine grains of cinnabar, besides considerable amounts of platinum”, and the primary sites of the gold — and, by implication, of the platinum — “have to be sought in the pre-tertiary Old Slates Formation and granite contacts of the interior”. The platinum is accordingly interpreted as a derivative of the pre-tertiary mineralised belt of the West-Atjeh interior, with the platinum grains eroded from the primary deposits and concentrated, together with the gold and cinnabar, in the pleistocene river terraces of the coastal basin.
The geological association of platinum with gold in the Sumatran alluvial deposits is also recorded at Pasilian (on the Umbilin River in central Sumatra), where Verbeek estimated a reserve of 10,000 tons of 68 % Fe ore in the gold-and-platinum-bearing alluvium, and in the Benkulen and Palembang placers. The West-Atjeh occurrence is, however, the only Sumatran locality for which colonial-era platinum production figures are recorded.
The M.A.E.M. Geudong Concession production (1940-1941)
The only recorded colonial-era platinum 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 platinum byproduct was “some kilograms per month”. The platinum was recovered, together with the gold, by amalgamation and Wilfley tables. For the full account of the M.A.E.M. operation see the entries on M.A.E.M. and Geudong Concession.
The M.A.E.M. operation was suspended by the Pacific War and the 1942 Japanese invasion, and no subsequent colonial-era platinum production is recorded for Atjeh. The total colonial-era platinum production from the Geudong Concession is accordingly the product of “some kilograms per month” over the operation’s active period (probably 1940 and part of 1941), which would amount to a few tens of kilograms in total. The modest scale of this production reflects the modest scale of the M.A.E.M. operation itself, which was — despite its two bucket dredges and 270,000-cubic-yard monthly capacity — a single-concession operation in a single Atjeh coastal basin.
Place in the East-Indian platinum record
Van Bemmelen’s general account of the East-Indian mineral production records platinum production of 1,045 grams in 1940 and 1,023 grams in 1941 for the entire East Indies. The M.A.E.M.’s “some kilograms per month” platinum byproduct from the Geudong Concession — if sustained over a full year — would accordingly have accounted for a substantial fraction of the East-Indian platinum total. The West-Atjeh alluvial deposits are, in this sense, one of the principal platinum-producing localities of the colonial East Indies, and the M.A.E.M. operation is the principal documented instance of platinum production from an Atjeh mineral deposit.
Significance
Platinum in Atjeh is significant for the encyclopedia of Acheh history because it is the only documented colonial-era occurrence of platinum production on Atjeh territory, and one of the principal platinum-producing localities of the colonial East Indies. The M.A.E.M. operation on the Geudong Concession is the only recorded colonial-era platinum production on Atjeh territory, and the West-Atjeh alluvial deposits are accordingly the only Atjeh locality for which platinum production figures are recorded. The platinum byproduct of the M.A.E.M. operation is also part of the wider mineral geography of the Meulaboh coastal basin — the only Atjeh locality for which colonial-era mineral production (gold, platinum, and the implicit mercury recovery) is recorded — and it accordingly belongs to the high-point of the colonial mineral economy of Atjeh.
See Also
- Acheh
- Atjeh’s Westkust
- Basin of Meulaboh
- C. de Groot
- Geudong Concession
- Gold and silver in Atjeh
- M.A.E.M.
- Meulaboh
- Mercury in Atjeh
- Van Bemmelen’s The Geology of Indonesia (1949)
- 1940
- 1941
Source
The Geology of Indonesia, by R. W. van Bemmelen, Vol. II: Economic Geology (The Hague: Government Printing Office; Martinus Nijhoff, 1949), p. 121 (Basin of Meulaboh, gold-bearing black sands with cinnabar and platinum, M.A.E.M. production with platinum byproduct), p. 5 (Table 2: East-Indian mineral production, platinum figures for 1940–1941).