|Gravity and magnetic field measurements in the eastern Banda Sea|
Woodside, J.M.; Jongsma, D.; Thommeret, M.; Strang van Hees, G.; Puntodewo (1989). Gravity and magnetic field measurements in the eastern Banda Sea. Neth. J. Sea Res. 24(2-3): 185-203
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
|Authors|| || Top |
- Woodside, J.M.
- Jongsma, D.
- Thommeret, M.
- Strang van Hees, G.
New gravity data from the eastern Banda Sea better define the trends and isostatic relations within the region of the complex Snellius-II Triple Junction. These and a complementary set of new magnetic anomaly data confirm the neotectonics there through their direct positive correlation with topography within the Aru Trough region in particular. The magnetic anomalies over selected structural features indicate either highly magnetic material in the sediments or, more plausibly, magnetic (volcanic?) material associated with and beneath the topographic features in the Aru and Weber Troughs. There is a discontinuity along the proposed westward extension of the Tarera-Aiduna Fault between the Seram subduction zone and the Aru Trough/Kuenen Bank area. Larger variations of gravity are observed to the south than to the north of the discontinuity; and the magnetic trends change, although both the gravity and magnetic anomalies exhibit a northeast-southwest trend obliquely across the southeastern section of the Seram Trough, suggesting that the tectonic break between the Seram and Aru Trough regions is not unequivocal. The gravity high over Kuenen Bank is modelled by elevation of crust by about 1100 m; but the accretionary complex of the Seram Trench to the north lies over dynamically-depressed crust of the subducting plate. The Weber Basin gravity anomaly is complex also, showing differences along and across the Trough; however it can be said in general that the crust is excessively depressed and thinned. Positive gravity anomalies over the outer part of the accretionary complex of the Timor-Tanimbar portion of the subduction zone suggest that this part of the complex is either rising above a rising or shallower subducting plate, or contains a substantial additional component of denser material. A major strike-slip feature may be present to the northeast of Tanimbar, cutting the accretionary complex obliquely.