Geological Applications of LANDSAT Thematic Mapper Imagery:
Mapping and Analysis of Lineaments in NW Penisula Malaysia
Juhari Mat Akhir and Ibrahim Abdullah
Department of Geology
Faculty of Physical and Applied Sciences
Universiti Kebangssan Malaysia
43600 Ukm Bangi Malaysia
Tel. 6-03-8292661 Fax. 6-03-8292490
E-mail :jma@pkrisc.cc.ukm.my
Abstract
Remotely sensed lineaments are often used as indicators of major fractures in near-surface. Earlier, lineament interpretation were made from aerial photographs. Recently, geologists have been interested in tracing lineaments from satellite images which have broad coverage under the uniform conditions. The Landsat Thematic Mapper TM which is covering part of north-west of Peninsula Malaysia have been digitally processed to enhance the visibility of lineaments. The contrast stretched of TH band 4 was found to be the best in displaying lineaments for the area, hence was further processed by using directional filters. The directionally and non-directionally filtered images together with the contrast stretched image of TM band 4 were used for lineament mapping and analysis for the study area. After tracing all lineaments, their orientations and lengths were determined and measured, and then analysed by preparing rose diagrams for analysis, interpretation and comparison with the published geological map. A lineament map with a scale of 1: 250, 000 of the study area is presented here, which is derived from the processed TM images.
This study indicates that he Landsat TM data is useful for locating and interpretation of the lineaments in the area. Geologic features, particularly lineaments, are readily interpreted despite dense vegetation cover. The study has shown that remote sensing data such as Landsat TM can be used in locating new in addition to previously known features, probably faults, which may be of economic importance in the area. Hence, lineament mapping and analyses from satellite data of the area can provide a new, rapid and stimulating overview for regional structural (lineament) study for mineral exploration, locating of new mineral deposits and planning the development of the selected area.
Introduction
The purposes of this study are (1) to show the applicability of the remote sensing data in structural geological study (lineament) in Malaysia; (2) To evaluate the images produced by several enhancement techniques for lineaments mapping; (3) To prepare structural map (lineament) based on the remote sensing data interpretation, then compared to the published geological map, and (4) to produce structural map (lineament), probably showing some newly discovered lineament which is subsequently may be used as a reference in future geological mapping. This paper presents the result of study on the lineaments from an area in north-west Malay Peninsula which are extracted and interpretated from digitally enhanced Landsat. Thematic Mapper images.
Term lineaments was originally used by Hobbs (1904) in his paper entitle "Lineaments of the Atlantic border region". He defined lineaments as significant lines of landscape that reveal the hidden architecture of the rock basement. However O'Leary et. al. (1976) defines lineament as a mappable, simple or composite linear feature of a surface whose parts are aligned in a rectilinear or slightly curvilinear relationship and which differ from the pattern of adjacent features and presumably reflects some sub-surface phenomenon. The definition by O'Leary is applied in this study.
In the past, lineaments interpretation were done based on the information extracted from air-photograph. Lately, satellite images were more frequently used for this purpose. However, in Malaysia the Landsat images used in geological mapping and lineaments interpretation are produced from non-digitally enhanced data (Foo, 1976); Sudrajat, 1978; Raj, 1882; Tjia & Zaiton, 1985; Almashoor & Tijia, 1987; Tijia, 1989 and Lai 1990). The benefits of using digitally processed satellite data are very well known and shown by several workers (Rowan et. al., 1974; Siegel&Abram, 1976; Condit & Chaves, 1979; Blodged & Brown, 1982 and Rothery, 1985). For that reason, in the more recent work, enhanced digitally processed satellite data were becoming more popular and frequently used in either geological mapping as well as in lineament intepretation and mapping (Juhari, 1990, 1991 & 1996; nor Bakri, 1993; Azlikamil et al., 1996 and Noraini et. al, 1996).
