TECTONOSTRATIGRAPHY AND STRUCTURAL PATTERN IN OFFSHORE BALI-LOMBOK, EAST JAVA BASIN

• Main Author: DANIL , DICKY
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/15389
• Institution: Institut Teknologi Bandung

East Java Basin is located in the back arc basin of modern subduction zone between the Indo-Australian Plate and the Eurasian plates. The East Java Basin can be separated into three main parts namely, Northern Platform, Central High, southern Basin. An Australian-origin microcontinent is believed to underlie the East Java Basin. <br /> <br /> <br /> Four general tectonostratigraphic units can be mapped by using 2D seismik data and well logs. Basement unit (Pre-Rift) underlies East Java Basin. Syn-Rift Unit (Pre-Ngimbang Fm. and Ngimbang Fm.) is restricted in Southern Basin, concentrated near E-W trending major fault representing extensional tectonic processes during from Paleocene to Eocene. Post-Rift Unit (shale member of <br /> <br /> <br /> Ngimbang Fm. and Kujung Fm.) covered the entire area. It is generated by thermal subsidence / sag in Oligocene. Syn-Inversion sediments (carbonate member of Kujung Fm.) thin above the W-E trending structures. Massive graben structures pattern have a E-W dominant direction which is likely inherited from tectonic processes long back as a part of Australian Continent. This fault zone develops from the reactivation of older fault zones in the form of normal faults forming the basin. Two thrust fault zones are thick skinned reverse fault in the north of the area and Bali-Lombok Thrust in the south of the area. <br /> <br /> <br /> Palinspatic Restoration and character of carbonate member of Kujung Formation suggest that the inversion tectonic initiated in the Early Miocene.