Lineaments Analysis Determined from Landsat Data Implication for Tectonic Features and Mineral Occurrences in Northern Loei Area, NE Thailand

Abstract

Digitally enhanced Landsat TM5 images along with geological and mineral occurrence information were applied for investigation of lineament systems in the northern Loei area, NE Thailand. Prior to visual interpretation, enhancement process was performed, including contrast stretching, edge enhancing and directional filter analyses. Image interpretation indicates 3 major lineament systems: north-south, northwestsoutheast, and northeast-southwest trending lineaments. The north-south trending lineaments are inferred to be closely related to substantial, nearly parallel thrust faults and fold axes, which, to some extent, follow the major and regional structural feature. Combination of major lineaments with pre-existing structural geology is useful for delineating tectonic features of the area. The overlay of mineral occurrences onto the lineament map indicates that the mineralizations have good coincidence not only with the shorter in northeast-southwest lineaments intersected by the longer in northwest-southeast lineaments but also with the intrusive igneous bodies. The mineral occurrences are mostly concentrated in areas of high-density lineaments. Our preliminary analysis also indicates that lineaments from Landsat interpretation fit fairly well with those of the geologic data. It is concluded that lineaments observed from enhanced spaced-borne images can be used to comprehend the tectonic setting and to select the target areas for follow-up mineral exploration.