Abstract: Satellite Imagery: The Foundations for Exploration Data Integration: A Case Study from Central Turkey

Mark Broadley

Satellite imagery at a regional level helps define the structural setting of an area, and at a detailed level subtle surface features are observed which, when integrated with sparse geophysical data, reveal new information about the subsurface. The Tuz Golu basin in Central Turkey is a fore-arc basin related to the Late Cretaceous-Palaeocene emplacement of the Kirshehir magmatic arc to the NE. It is composed of Upper Cretaceous to Pliocene limestones, sandstones and shales, with a major evaporite horizon in the Eocene.

Structural development of the basin is related to initial transpression associated with the oblique collision of the arc, followed by transtension during the Eocene, leading to the development of pull-apart basins and the activation of the evaporite horizon. The main play is related to the diapiric structures. The basin shows little relief, has been extensively cultivated, and has virtually no outcrop.

Regional Landsat MSS was used to cover central Turkey, the structural interpretation enabling the tectonic framework controlling the basin's development to be identified. The region was partitioned into distinct structural domains; Tuz Golu being dominated by NW-SE trending faults related to the oblique collision.

SPOT XS imagery was used to focus on the basin. The identification of faults, when integrated with drainage data, revealed the presence of structured topographic basins and aligned escarpments. The analysis of these patterns led to the lows being interpreted as pull-apart zones related to the Eocene transtension.

Previous gravity, magnetic and seismic surveys were digitised and integrated with the satellite derived interpretations, and revealed that gravity lows and seismic-identified structures corresponded with the zones of transtension from the satellite interpretations. The lack of magnetic signature associated with the pull-aparts added confidence to the interpretation that these structures were related to salt diapirism rather than igneous intrusions, as had been encountered in a previous drilling programme.

A final composite map outlined all of the zones of transtension, residual gravity lows and seismic derived intrusive structures, thus enabling a focused and coherent seismic programme to be planned.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France