ABSTRACT: Analysis of Synthetic Aperture Radar Data for Regional Tectonics and Lithologic Terrain Unit Interpretations in a Dense Tropical Forested Region in Malaysia

POSEHN, GARY A., and JAMES A. GENEREUX, Intera Information Technologies (Canada) Limited, Calgary, Alberta, Canada, and RICKY M. MANTARING, Idemitsu Oil Exploration (East Malaysia) Co., Ltd., Kuala Lumpur, Malaysia

Synthetic Aperture Radar (SAR) data were used to interpret regional structural elements and lithostratigraphic terrain units in northern Sarawak, East Malaysia. The high resolution SAR data enabled the definition of geologic terrain units and delineation of fold axes and faults that were sustained by field observations.

Geologic exploration in Sarawak in hindered by rugged terrain conditions. In addition, heavy rainfall and limited access routes render surface reconnaissance geologic evaluations difficult. Remote sensing is one tool that the exploration geologist may use to be more effective in field logistical concerns such as outcrop and sample point identification, lithologic and structural interpretation, seismic line lay-out and well location selection. Since SAR is an active microwave side-looking geometry highlights subtle but significant features otherwise invisible to other remotely sensed imagery data.

Visual SAR image analysis procedures used tone, texture, shape, size, shadow, and pattern to interpret nine (9) different geologic units in the area. Identification of previously unmapped lithologic units and detailed spatial delineation of published terrain units within the Tertiary stratigraphic sequences were accomplished.

The structural effects of transform faulting in generating tectonic foliation and warping earlier established fold patterns were mapped from SAR imagery. SAR has shown to be an excellent tool for deciphering the structure and tectonic complexities of the study area. Several interpreted transform fault zones not only corresponded to major boundaries of known tectonostratigraphic provinces in the Baram Delta/Greater Sarawak basin but were also confirmed by recent onshore geophysical data.

SAR geologic interpretation, when supplemented with field data, proved to be a cost-effective means of evaluating the dense tropical jungle and tectonically complex Tertiary basin margin within Sarawak, Malaysia.

AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)