Deep Crustal Imaging of East Java Sea-Makassar Strait Region Using Long-Cable 2d Seismic Reflection Data

James W. Granath¹, Peter A. Emmet¹, and Menno G. Dinkelman^2
1Consultant, ION Solutions-GX Technology, Houston, TX
²BasinSPAN Programs, ION Solutions-GX Technology, Houston, TX

In the past five years ION-GXT has been at the forefront in the acquisition of regional 2-D seismic reconnaissance surveys that image deep crustal structure to better understand the tectonic history of basin-scale geological provinces. In early 2008 ION-GXT completed such a regional 2-D survey of the Java Sea back-arc region and the Makassar Straits between the islands of Java, Kalimantan, Sulawesi, and Flores.

The survey is comprised of over 9,000 line-kms of 2D data. Acquisition parameters include a 25 m shot interval, 12.5 m group interval and maximum offset of 9,000 m. The record length is 18 sec and the data is processed to pre-stack time image of 16 sec and pre-stack depth image of 40 km record length. Integration with simultaneously-collected gravity and magnetics data constrains interpretation in that it places limits on the velocities of deeply buried lithologies that are critical to the seismic PSDM processing workflow.

Highlights of the features imaged in the data set include the relationships of oceanic crust to surrounding orogenic crust in the Flores Basin, active rifting in the mouth of the Bone Basin, recurrent rifting and inversion nucleated on Cretaceous ‘basement’ structures, relationships of the Paternoster platform to the Makassar Straits structures, and the nature of the crust throughout the area. The extent and the deeper architecture of known and potentially new hydrocarbon-bearing basins are illustrated in many of the lines. Several sedimentary prisms below what has been taken previously as acoustic basement are evident, and add to the pre-Tertiary and early Tertiary history of the area.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery