Sumatra, Sunda Shelf, Natuna - Bibliography of Indonesia Geology

(Lake Toba area 'Kualu Fm' open marine mudstone with Carnian deeper marine bivalves Halobia tobaensis
n.sp. and Halobia kwaluana. Carnian-Norian subdivided into four zones based on Halobia species)
Koesoemadinata, R.P. & T. Matasak (1981)- Stratigraphy and sedimentation: Ombilin Basin, Central Sumatra
(West Sumatra Province). Proc. 10th Ann. Conv. Indon. Petrol. Assoc., p. 217-249.
(Ombilin basin asymmetric intermontane basin, folded in E part. Carboniferous Limestones (Kuantan Fm),
Permian volcanics (Silungkang Fm) and Triassic sediments, intruded by granites. Paleocene Sangkarewang Fm
lacustrine shales with fish fossils, interfingering with Brani Fm alluvial fan conglomerates. In NW these units
overlain by probably Eocene coal bearing Sawahlunto Fm. Paleogene ~2600 m thick, overlain by Ombilin Fm
marine clay-marls (Lower Miocene), unconformably overlain by Ranau Fm Quaternary tuffs)
Koning, T. (1985)- Petroleum geology of the Ombilin intermontane basin, West Sumatra. Proc. 14th Ann.
Conv. Indonesian Petrol. Assoc., 1, p. 117-137.
(Sinamar No. 1 first oil exploration well in Tertiary intermontane basin in Indonesia. Ombilin Basin rel. small
(~1500 km2), but up to 4600 m of M Eocene -E Miocene sediments with significant depositional hiatuses.
Massive debris flows and extensive alluvial fan deposits on basin margins and large Eocene lake in center.
Uplift and erosion since M Miocene reduced Ombilin Basin to present area. Located in Sumatra magmatic arc,
but temperature gradients cooler than Sumatra back-arc basins. Eocene lacustrine shales and Oligocene
marine shales likely source rocks for hydrocarbons tested in Sinamar 1 and oil seeps along basin margins)
Koning, T. (1992)- Oil production from Pre-Tertiary basement rocks in Indonesia: examples from Sumatra and
Kalimantan. AAPG Ann. Mtg. Calgary 1992 (Abstract)
(Beruk NE (1976) field in C Sumatra produces from pre-Tertiary basement. Beruk NE 1 tested 1680 BOD and
~2 MBO produced from metaquartzites, weathered argillites and granite. Radiometric ages E Permian- E
Cretaceous. Unusual production problems due to reservoir variability, four separate oil-water contacts, and
possible unrecognized water-bearing fracture systems. Tanjung field in Barito basin, S Kalimantan (1938),
produced 21 MBO from Pre-Tertiary volcanics, pyroclastics and metamorphosed sandstones and claystones,
locally weathered and fractured. Both fields faulted anticlines, and oil source rocks adjacent Tertiary shales)
Koning, T. & K. Aulia (2000)- Exploration in the Ombilin intermontane basin, West Sumatra. AAPG Int. Conf.
Bali 2000. (Abstract only)
(Caltex 1984 Sinamar-1 first well in intermontane Ombilin Basin in Barisan Mts., with noncommercial oil and
gas. Apache 1994 South Sinamar-1 was 1140 m dry hole. Despite small area (1500 km2), up to 4600 m of
Tertiary sediments. Basin initially Early Tertiary intermontane trough with debris flows and alluvial fans on
margins and Eocene lake in center. Uplift-erosion since M Miocene reduced original basin extent. Although in
present-day magmatic arc and partially covered by volcanics, T gradients lower than Sumatra back-arc basins.
Eocene lacustrine shales likely source for hydrocarbons in Sinamar-1 and two oil seeps along basin margin)
Koning, T. & F.X. Darmono (1984)- The geology of the Beruk Northeast Field, Central Sumatra; oil production
from Pre-Tertiary basement rocks. Proc. 13th Ann. Conv. Indon. Petrol. Assoc., p. 385-406.
(Beruk NE oil field in C Sumatra discovered in 1976, testing 1680 BOPD from Pre-Tertiary fractured
metaquartzites, weathered argillites, and weathered granite. Radiometric ages mainly Jurassic- E Cretaceous.
Bohorok Fm at nearby Cucut 1 well contains an E-M Carboniferous flora)
Koolhoven, W.C.B. & W.A.J. Aernout (1928)- De afzettingen van Simau (Res. Benkoelen). De Mijningenieur
9, p. 150-163 and p. 177-187.
('The deposits of Simau, Residency of Bengkulu'. On gold-silver deposits in Simau mine area, SW Sumatra.
These mines were in production by 'Simau Mijn maatschappij' from 1910-1941 and connected to the outside
world only by 30km narrow guage rail line)
Kopp, H.. E.R. Flueh, D. Klaeschen, J. Bialas & C. Reichert (2001)- Crustal structure of the central Sunda
margin at the onset of oblique subduction. Geophys. J. Int. 147, 2 p. 449-474.
(Data off S Sumatra and Sunda Strait show lateral increase in dip of subducted plate from 5° to 7° below outer
high off Sumatra to Sunda Strait. Downgoing slab traced to >30 km depth. Backstop structure underlying
Bibliography of Indonesia Geology v. 4.1 55 www.vangorselslist.com July 2012