Geothermal resource of Sumatra

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Geothermics (International Journal of Geothermal Research and its Applications); (United States)

DOI:https://doi.org/10.1016/0375-6505(93)90042-L· OSTI ID:5821679

Hochstein, M P ^[1]; Sudarman, Sayogi ^[2]

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1. Univ. of Auckland (New Zealand). Geothermal Inst.
2. Pertamina, Jakarta (Indonesia). Geothermal Section

There are at least 30 high temperatures systems (with inferred reservoir temperatures > 200 C) along the active Sumatra Arc that transfer heat from crustal intrusions to the surface. These systems, together with eleven active volcanoes, five degassing volcanoes and one caldera volcano (Lake Toba), are controlled by the Sumatra Fault Zone, an active mega shear zone that follows the median axis of the arc. At least half of the active and degassing volcanoes are associated with volcanic geothermal reservoirs containing magmatic gases and acid fluids. Large, low temperature resources exist in the Tertiary sedimentary basins of east Sumatra (back-arc region), where anomalously higher thermal gradients (up to 8 C/100 m) have been measured. Volcanic activity was not continuous during the Cenozoic; subduction and arc volcanism probably decreased after the Eocene as a result of a clockwise rotation of Sumatra. In the Late Miocene, subduction started again, and andesitic volcanism reached a new peak of intensity in the Pliocene and has been continuous ever since. Rhyolitic volcanism, which has produced voluminous ignimbrite flows, began later (Pliocene/Pleistocene). All known rhyolitic centers associated with ignimbrite flows appear to lie along the Sumatra Fault Zone.

• OSTI ID: 5821679
• Journal Information: Geothermics (International Journal of Geothermal Research and its Applications); (United States), Vol. 22:3; ISSN 0375-6505
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
GEOTHERMAL RESOURCES
RESOURCE ASSESSMENT
INDONESIA
GEOLOGIC FAULTS
GEOLOGIC HISTORY
RESERVOIR TEMPERATURE
SUBDUCTION ZONES
VOLCANISM
VOLCANOES
ASIA
DEVELOPING COUNTRIES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
ISLANDS
RESOURCES
150100* - Geothermal Energy- Resources & Availability