TECTONOSTRATIGRAPHY AND TECTONIC EVOLUTION OF SUMBA ISLAND

• Main Author: RESKI, EZIDIN
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/41611
• Institution: Institut Teknologi Bandung

Kata Kunci : Tektonostratigrafi, Pulau Sumba, Savu iii ABSTRACT TECTONOSTRATIGRAPHY AND TECTONIC EVOLUTION OF SUMBA ISLAND by Ezidin Reski NIM : 22011006 Geographically, the research area of geological and tectonic setting of Sumba Island is located between between 9° 00' 00" S - 10° 30' 00" S, and 118° 50' 00" E - 121° 00' 00" E with an area of ± 11.000 km2 and geologically it is situated between Lombok and southwestern tip of Savu Basin. The study covers area of Sumba Island and north of Sumba Island. Sumba Island is bounded by a main fault which could cause the replacement of it in Eocene to its position today. Unlike other fore arc islands such as Savu, Roti, and Timor Islands; Sumba Island does not show great compression effect. Four main tectonostratigraphic units mapped using field data and 2D seismics. There are four units of tectonostratigraphy, namely Pre-Rift Unit (Lassipu Formation) of Cretaceous age, Syn-Orogenic unit and Post-Orogenic (Massu Formation, Watopata Formation, and Tanahroong Formation) of Paleocene- Eocene, Post-Orogenic unit (Paumbapa Formation, Pamalar Formation, Tanahdaro Formation, Waikabubak Formation, and Kananggar Formation) of Oligocene-Pliocene and Recent-Orogenic (Kaliangga Formation) of Pleistocene age. Structural pattern trending northwest-southeast at Sumba Island was occurred on the first collision, between Sunda Microcontinent and East Java Microcontinent. iv The subsequent structural pattern which is a west-east normal fault of Eocene age was formed by rollback occurrence. Since Oligocene until now, Sumba Island has not shown any great deformation and is more dominated by sagging process.