SUBSURFACE STRUKTURAL MODEL OF BURU, SERAM, AND SURROUNDING ISLANDS USING GRAVITY AND AEROMAGNETIC DATA

• Main Author: Muti'ah, Siti
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71310
• Institution: Institut Teknologi Bandung

Buru, Seram and surroundings islands, have a complex structure due to interaction between Australian and Pacific plates. Buru and Seram Island are composed of the same Paleozoic metamorphic rocks; Mesozoic-Quaternary volcanic rocks and marine-terrestrial sediments. Ambon, Haruku, and Saparua, consist of andesitic volcanic rocks. Even though the islands are located closely to each other, the tectonic setting is still debatable due to significantly different structures. To understand its tectonics setting, a study was carried out using aeromagnetic data and gravity from ground survey. Structural delineation is carried out by processing the total horizontal gradient from complete Bouguer anomaly and aeromagnetic data which are then used to support the forward modeling. Metamorphic uplifting seen from forward modeling where on Buru Island is due to batholith intrusion while Seram is thrust faults. Origin mechanism of the two islands was once as a microplate with a north-south trending and separated by Pacific Plate movement. Buru Island as the northern and Seram the southern part of microplate, rotated around 225? and 90? counterclockwise to reach its present position. The large number of heat sources in the study area is also assumed caused by fractures from the rotational movement, besides from volcanic arc activity.