Sedimentology and diagenesis of a rift basin lacustrine sandstone: Pematang group, central Sumatra, Indonesia

Conference · Thu May 01 00:00:00 EDT 1986 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:5167232

Janks, J S; Kelley, P A; Williams, H H

The Central Sumatra basin is a back-arc basin that formed during the Paleocene as a series of half-graben structures. These early formed half-graben structures were filled with nonmarine clastics and lacustrine sediments of the Pematang Group, sourced from local highland areas. The Pematang Group consists of the Lower Red Beds, Brown Shale, Coal Zone Member, and Lake Fill Formation (in ascending order). The Pematang Group sedimentology is intimately related to the regional and basinal tectonic development and history. Sandstones of the Pematang Group are predominantly sublitharenites and litharenites; feldspars are rare. Sandstone diagenesis is relatively uniform regardless of the depositional environment. Diagenetic modifications include compaction, early calcite and dolomite cementation, quartz overgrowth formation, unstable rock-fragment dissolution, kaolinite precipitation, siderite formation, and local illite formation. Secondary porosity accounts for up to 50% of the effective porosity and was created by rock-fragment dissolution. This dissolution is probably caused by the organic acids released during kerogen maturation. Stable isotope data from diagenetic siderite are presented.

• Research Organization: Texaco USA, Houston, TX
• OSTI ID: 5167232
• Report Number(s): CONF-860624-
• Journal Information: Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 70:5; Conference: American Association of Petroleum Geologists annual meeting, Atlanta, GA, USA, 15 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

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INDONESIA
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DIAGENESIS
POROSITY
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KEROGEN
MATURATION
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SEDIMENTARY BASINS
SOURCE ROCKS
ASIA
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
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