PALEOGEOGRAPHY RECONSTRUCTION OF PASSIVE MARGIN DEPOSIT WITHIN PLIOSEN-RECENT AGE IN THE WESTERN PART OF SOUTH MAKASAR BASIN

• Main Author: WISATRIA, BACHESHA
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/15113
• Institution: Institut Teknologi Bandung

Continental margin deposit contain rich record of Earth history, due to influence of many complex factors within the atmospehere (e.g. climate, storm), the lithosphere (e.g. orogeny, subsidence) and the biosphere (e.g. carbon cycle). The purpose of this study is to reveal the understanding of morphology development, sedimentary processes and stratigraphic order of continental margin deposit in the western part of South Makasar Basin. Passive margin interval as main object study consist of rimmed shelf carbonate deposit. Data analysis conducted using seismic stratigraphy approach and model analog derived from previous study. Morphology analysis is performed using model analog derived from Swenson (2005), gravity mass flow model of Grand Banks (Piper et al, 1999) and rimmed carbonate model from Schlager (2005). Mechanism of deepwater sedimentation is determined using modern analog of Mass Transport Complex and Thaw Slumps deposit. Stratigraphy analysis of rimmed carbonate growth is interpreted using seismic stratigraphy approach (Mitchum, 1977) and humid-rimmed shelf carbonate sequence model (Handford & Loucks, 1993). Geological processes determined from analyses above therefore being gathered and reconstructed into 3D paleogeography model. The result of analysis showing that morphology development of passive margin was influenced by subsidence, normal fault activity and backstepping geometry of carbonate growth. Sedimentatry processes occured in study area is comprised of debris flow, slumps and backstepping shelf carbonate sedimentation. Based on termination of seismic reflector, shelf carbonate growth in study area can be classified into three sedimentation sequences. Indication of increasing subsidence rate is identified during deposition of sequence 2 and force regression is identified during deposition of sequence 3. These events triggered the occurences of gravity mass flow along the continental margin's slope.