Geologi Sumatera.pptx
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This document summarizes the tectonic setting and geology of the Sumatra region in Indonesia. It describes how Sumatra is located along several major tectonic plate boundaries, including the Great Sumatra Fault zone. It outlines the plate tectonics movements that have shaped Sumatra, including convergence, divergence, and transvergence. It also describes the major tectonic elements of Sumatra, including the Sunda Shelf, Bukit Barisan mountain range, and Sumatra Trench. Furthermore, it summarizes the pre-Tertiary basement rocks, Tertiary sedimentary basins, and major fault systems of Sumatra, including the Trans Sumatra strike-slip fault system and Paleogene basement fault
Geologi Sumatera.pptx
- 4. Tipe Pembentukan Gunung Convergent Boundaries : (a) oceanic vs continent, (b) oceanic vs oceanic, (c) continent vs continent Press and Siever (1998)
- 5. Convergent Boundaries : (a) oceanic vs continent (Subduction), (b) continent vs continent (collision) Press and Siever (1998)
- 9. Katili(1973) Present Plate Boundaries in South East Asia
- 10. Indonesia Tectonic Boundary West : Great Sumatra and Mentawai duplex mega-shears, Sumatra Trench South : Java Trench-Timor-AruTrough East : ArafuraPlatform (Australia Craton) North : SorongFault, North SulawesiTrench, SCS (South China Sea) Plate Tectonics Movement In Indonesia Involves : Convergence, (collisions, subductionand obduction) Divergence (rifting, break-up and subsequent seafloor spreading) Transvergence(wrench faulting) involving translation and rotation Plate tectonics subdivision of indonesia West Indonesia with Sunda Platform acting as a continental core Central Indonesia consising of fragmented microcontinents represented by Sulawesi and the Banda Arc East Indonesia with the Arafura Platfrom acting as a continental core
- 11. Tectonic Framework of Indonesia
- 13. Sukamto(2000)
- 14. Sukamto(2000)
- 21. SUMATRA MAJOR TECTONIC ELEMENTS The SundaShelf borders the back arc basin to the east AsahanArch, BukitTigapuluhMountains and LampungHigh partitions the back-arc basins The BukitBarisanRange : NeogeneMagmaticarc, separates the back-arc basins from West Sumatra fore-arc basins The Outer Arc Islands : accretion wedges The Sumatra trench: an oblique subductionzone
- 22. Sumatra Pre-Tertiary Basement Pre Tertiary rocks are exposed in the BarisanRange, TigapuluhMountains and LampungHigh. Sumatra Pre-Tertiary rocks have been analyzed into separate terranesconsisting of :highly tectonizedPaleozoic and Mesozoic terranesPaleozoic to Mesozoic intrusive rocks Melange(ophioliticrocks). Pre-Tertiary terranesare interpreted as a collage of Asian and Gondwananmicrocontinents.
- 24. SUMATRA TERTIARY BASINS Back-arc and partly fore-arc basins are underlain by continental crust. The magmaticarc, BarisanRange, uplifted Pre-Tertiary rocks forms border to the basins. Paleogenerift basins extend from back-arc to fore-arc basins across the BukitBarisan. Volcanism is limited to Paleogene(in the Southwest) and Plio- Pleistocene. The presence of the Great Trans-Sumatra wrench fault (SemangkoFault) along the BukitBarisan.
- 28. Sumatra Tectono-Stratigraphic System From top to base : Syn-orogenicdeposition in a back-arc basin : regressive (Mid-Miocene-Recent)rising BarisanRange clasticsource Post-rift deposition in a shelfalbasin : transgressive(Early Miocene) Sundalandclastics source and carbonates Syn-rift deposition in active rift-valley basins : one or more rift phases (?Eocene-Oligocene)local clasticsource
- 29. Sumatra Major Fault System THE TRANS SUMATRA STRIKE-SLIP FAULT SYSTEM : active since Early Tertiary times THE PALEOGENE BASEMENT FAULT SYSTEM : This fault system resulted in the Paleogenegraben-half- grabensystem with syn-rift deposition The Sumatra PaleogeneFault System extends SE to the NW Java basinalarea
- 31. The PaleogeneBasement Fault System This fault system consists of two main componentsN-S componentWNW-ESE componentIn South Sumatra a NE- SW component is present This fault system cuts clear across the BarisanRange, beneath the fore-arc basin. This fault system is responsible for the development of Paleogenegraben-half-grabenbasin system with syn-rift deposition forming important oil kitchens.
- 34. PaleogeneBasement Faults Explanation Moulds (1989): Faults are mainly N-S and was created due to the E-W directed extensional regime during the initial stage of the N- S directed stress caused by the subduction. Other explanation: transtensionalfaults due to the dextral wrenching movements of the Indian Ocean Plate relative to the Sundacontinental plate
- 35. TERIMA KASIH