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

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1 ScienceAsia 3 (24): Lineaments Analysis Determined frm Landsat Data Implicatin fr Tectnic Features and Mineral Occurrences in rthern Lei Area, E Thailand Kachentra eawsuparp 1,2* and Punya Charusiri 1* 1 Department f Gelgy, Faculty f Science, Chulalngkrn University, Bangkk, 133, Thailand. 2 Gelgical Resurces Cnservatin and Management Divisin, Department f Mineral Resurces, Bangkk, 14, Thailand. * Crrespnding authr, kachen@dmr.g.th and Received 25 Feb 24 Accepted 23 Jun 24 ABSTRACT: Digitally enhanced Landsat TM5 images alng with gelgical and mineral ccurrence infrmatin were applied fr investigatin f lineament systems in the nrthern Lei area, E Thailand. Prir t visual interpretatin, enhancement prcess was perfrmed, including cntrast stretching, edge enhancing and directinal filter analyses. Image interpretatin indicates 3 majr lineament systems: nrth-suth, nrthwestsutheast, and nrtheast-suthwest trending lineaments. The nrth-suth trending lineaments are inferred t be clsely related t substantial, nearly parallel thrust faults and fld axes, which, t sme extent, fllw the majr and reginal structural feature. Cmbinatin f majr lineaments with pre-existing structural gelgy is useful fr delineating tectnic features f the area. The verlay f mineral ccurrences nt the lineament map indicates that the mineralizatins have gd cincidence nt nly with the shrter in nrtheast-suthwest lineaments intersected by the lnger in nrthwest-sutheast lineaments but als with the intrusive igneus bdies. The mineral ccurrences are mstly cncentrated in areas f high-density lineaments. Our preliminary analysis als indicates that lineaments frm Landsat interpretatin fit fairly well with thse f the gelgic data. It is cncluded that lineaments bserved frm enhanced spaced-brne images can be used t cmprehend the tectnic setting and t select the target areas fr fllw-up mineral explratin. KEYWORDS: Landsat image, lineament, mineralizatin, nrtheastern Thailand, Lei, tectnic. ITRODUCTIO Lei area, the majr prvince f E Thailand clse t Las (Fig. 1), has been a fcus f interest fr several 2 97 E 1 Chiangmai Las ' decades due t its significant mineral resurces 1-4. Jacbsn et al. 5 made the first systematic mapping fr metal-depsit investigatin f the Lei area and its surrundings. Charusiri (1989) made a recnnaissance 24' 15 Study area Thailand Bangkk Lei Km ' Fig 1. Map f the Lei study area with majr district bundary and verlain Un-enhanced image data and Index map f Thailand shwing the area under study. 1 2 km Figure 1 eawsuparp K.

2 27 ScienceAsia 3 (24) survey n granitic rcks in the Lei area using the 4 Ar/ 39 Ar methd, and Middle t Late Triassic was prpsed fr the majr age f granitic magmatism. Hwever, few wrks have been fcused n remte-sensing interpretatin f the study regin. The pineer wrk is that f Jantaranipa et al. 6 wh applied multispectral scanner (MSS) space-brne images t visualize lineaments f the Lei area. It was demnstrated that the selectin f target areas fr mineral r petrleum explratin culd be achieved by using integrated image data shwing high-density lineaments and relevant maps. This study is an attempt t crrelate lineaments (r gelgically linear features) visible n Thematic Mapper (TM) Landsat imagery, which has becme the essential remte sensing tl fr gelgical explratin. The better spatial reslutin (3 m) f TM imagery cmpared t that f the Landsat MSS (8 m) and the extra spectral channels prvide mre detailed infrmatin fr gelgical mapping. Many reviewed and specialist papers written n Landsat TM data, such as Abram et al. 7, Crsta and Mre 8 and Drury 9, als emphasized these advantages. Fr this study, details f lineaments, including gemetry, pattern, distributin and density, are invlved in the lineament analysis. The interpretatin f majr lineaments related t the structural tectnics and the recnstructin f structural gelgic map was carried ut in this wrk. Overlay f new mineral ccurrences map nt lineament map has helped t define these relatinships. t all bands f the Landsat images can be applied. Only band-7 image depicts gd cntrast and clarity as earlier applied by Charusiri et al 1. In this study, the enhanced images are applied fr interpretatin withut field supprt f grund-truth evidences. Interpretatin, hwever, has been dne tgether with gelgical map f Bunpas 2 and Chairangsee et al. 4 and mineral ccurrences map frm Ecnmic Divisin, Department f Mineral Resurces (DMR), Thailand (Mineral Resurces Develpment Prject) 11. The study area is lcated in the nrthern part f the Lei prvince at latitudes between 11 and and lngitudes between and 18 5, as shwn in Fig 1. GEOLOGIC SETTIG There are varius literatures regarding gelgy in Lei and neighbring areas. Gelgic setting f this paper is summarized frm the reprt f Bunpas 2 at scale 1:1, and f Chairangsee et al. 4 at scale 1: 5,. Accrding t the gelgical map f Lei area (Fig. 2), rck sequences begin with Middle Palezic metamrphic rcks, which mainly include quartzite and phyllite. In the eastern part f the area, these metamrphic rcks (a M Frmatin) are uncnfrmably verlaid by alternated strata f shale and siltstne with tuff and intercalated limestne (Ban ng Frmatin). Intensely flded chert (Pak Chm Frmatin) f Middle t prbably Palezic age 12 is restricted t the western part. The chert unit is situated adjacent t spilitic basaltic rcks ranging in age frm Devnian t Permian. 13 Bth chert and basalt units frm a lng, narrw nrth-suth trending belt. This basaltic unit extruded n the sea flr and frmed huge masses f vlcanic tuff and pillw lava assciated with spradic manganese depsits. Mrever, serpentinite bdies, expsed spradically as a narrw nrth-suth trending zne, have been reprted in the eastern part f the Lei area. 4 In Late middle Devnian t Carbniferus; thick graywacke intercalated with shale and reef limestne (Wang Saphung Frmatin) was discvered in several places. Late Palezic, reef limestne (Tham am Mahland, Huai E-Lert and Pha Dua Frmatins) lie uncnfrmably ver the lder rcks. Felsic rhylitic tuff and grandirite f mstly Triassic age 3 cver a large area lcated mstly in the central part f the investigated area. Lwer Jurassic nn-marine sediments f the Khrat Grup ccupy principally in the eastern margin f the Lei area. In the study area, we recgnize tw majr structural features, viz. flds and faults. The main faults and fld axes rient in the nrth-suth directin. Additinally, Bunpas 2 and Chairangsee et al. 4 reprted the uncnfrmities in the mapped area between strata f different ages, fr example, between Permian and Late Triassic and between Lwer Carbniferus and Devnian. Hwever, they are stratigraphically prly defined. Bunpas 14 recgnized the Lei area as part f the majr fld belt called Lei Fld Belt which crrespnd t sme extent with the Lei - Phetchabun K Chang vlcanic rcks. Large anticlines and synclines, whse axes are mainly in the nrth-suth directin, are recrded especially in Silurian and Permian rck sequences. Many flds are dislcated by several sets f faults. Strike-slip faults riented in nrtheast-suthwest and nrthwest-sutheast directins seem t be dminant and they dislcate majr flds and preexisting thrust faults. Sinistral mvement, which is mre cmmn than dextral mvement, is present especially in the western part f Lei. This is prbably due t the cntinuus clckwise rtatin f cntinental SE Asia. 1 The large nrth-suth trending verthrust in the eastern part f Lei area separates Silurian-Devnian metamrphic rcks frm Carbniferus sedimentary rcks. IMAGE PROCESSIG AD EHACEMET METHODS Remtely sensed images play a significant rle in defining gelgical structures and tectnic fabrics f

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4 272 ScienceAsia 3 (24) Fig 3. Interpreted lineament map (a) with the enhanced image by edge enhancement, (b) with the enhanced image by S directinal filtering methd (zm in blck frm (a)), (c) with the enhanced image by E directinal filtering methd (zm in blck frm (a)), (d) with the cmbinatin f lineaments frm (a), (b) and (c). 18 ' 17 12' (a) 1 24' 2 km 18 ' (b) 24' 17 12' the study area. Lineaments are deciphered primarily using satellite imageries frm Landsat Thematic Mapper (TM) band 7 (see Fig. 1). The remte-sensing images have been acquired in digital frms as tw-dimensin arrays r rasters made up f pixels. A digital number that represents the energy f the electrmagnetic radiatin waveband being mnitred assigns each pixel. An image prcessing nrmally cnsists f three main steps; namely, rectificatin, enhancement and data extractin. The rectificatin is used t imprve crrespndence f image data within the represented scene. The enhancement step is nrmally undertaken t imprve ability t identify features f interest in the imagery. The data extractin step is used t interpret and classify each prject such as land cver and gelgy. The detailed explanatin fr each step can be fund in eawsuparp. 15 In this study, nly the enhancement fr structural analysis is invlved. Image enhancement is an peratin designed t ptimally display infrmatin frm imagery data fr visual interpretatin. An image usually cntains mre infrmatin t be displayed in a single picture. The image enhancement entails selectin f the subset f infrmatin t be displayed as well as the ptimum display f that infrmatin. In this study, the digital images frm Landsat TM 5 are prcessed and displayed using the 3 main prgrams namely IDRISI, MapInf, and GEOSOFT prgrams. Cntrast stretching is valuable in enhancing Landsat data. Because the expsure time in the Landsat is nt variable, the sensitivity f the instrument must be set s thse scenes f different albed d nt saturate the sensr. Thus, as shwn in Fig. 3(a), the data are likely t ccupy nly the available gray level. The un-stretched image appears very flat r lw cntrast when displayed. Filtering is als a useful image enhancement. The edge-enhancing filter can be used t highlight any (c) Figure 3 eawsuparp K. changes f gradient within image features such as structural lines, cmmunicatin lines r circular features. The directinal filters are applied t image using a cnvlutin prcess by mean f cnstructing a windw nrmally with a 3x3 pixel bx. The directinal filters can be applied in rder t highlight lineaments by cntrlling the sunlight directin in crss with the main structural gelgy. Figs. 3(b) and 3(c) illustrate the enhanced images by S and E directinal filtering methd, respectively. Based upn ur analysis using IDRISI prgram, we cnsider that the edge enhancement, the directinal filters in nrth and nrtheast directins and the cntrast stretching, are practical enhancement methd, and these cnstitute the main image enhancement steps. The cntrast stretching includes the linear and 2.5 saturatin rates (-the maximum brightness that can be assigned t a pixel n display device, and crrespnds t digital number (D) f 255) have been applied successfully fr lineament mapping. The D refers t the value f a variable recrded fr each pixel in an image as a binary integer, usually in the range As a result, the ttal lineaments f 589 lines are detected. The results with edge and directinal filters are shwn in Fig 3(d). RESULTS AD IMAGERY ITERPRETATIO Fig. 4 displays the lineament map using the Landsat TM image f band 7 by the cmbinatin f cntrast stretching and filtering methds. The lineament analysis is dne prir t the verlaid gelgical map was examined, and any knwledge f mineral ccurrences is acquired in rder t eliminate any pssible bias. Since the image requested is prepared digitally in the rectangular frm, s part f the study area als includes in part f La PDR (see Fig.1). Thus the usefulness f this map is t describe the cntinuity f lng lineaments extending frm E Thailand t La (d)

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6 274 ScienceAsia 3 (24) PDR. In this study, interpretatin is perfrmed nly in Thailand s the demarcates the nrthern end fr this analysis. In ur current investigatin, we subdivide the study area int three parts, namely western, central and eastern parts by using the difference in pattern, gemetry, and density f lineaments. Fr cmparisn f nature and styles f lineaments, the gelgical map f this area 16 is verlaid nt the lineament map as shwn in Fig.4. The length f lineaments is described in term f majr (>1 km lng), and minr (<5 km lng) lineaments. Linear features f this study area can generally be equated with the structural elements such as faults, jints, r fractures. Minr linear features, such as small-scale fault and jints, are ften nt apparent n the imagery due t limitatins f reslutin. Wester estern n Part Main rientatins f majr lineaments are rughly in the nrth-suth directin. Sme lineament patterns trend in the rughly nrtheast-suthwest directin. In the nrthern part f this zne, lng majr lineaments are bserved in nrth-suth t nrthwest-sutheast directins. Lineaments f these directins run frm the suthern part f the mapped area in Wang Saphung and extend t the nrth in Las (see als Fig. 1). These lineaments are lcated almst at the cntact between Meszic clastics and Upper Palezic rcks. These nrth-trending lineaments in the nrthern part are shifted tectnically t sutheast directin in the suthern part. In sme part, these lineaments are subsequently crsscut by the nrtheast-trending lineaments. The linear features in this zne frm a cmplex pattern especially in the nrthwestern (t La PDR) by which multi-directinal lineaments are clearly bserved. Central Part Curvi-linear and circular features are unique features f the central part. The circular features, as indicated by curved drainage patterns in the enhanced images, mark the area that is cncealed by igneus plugs. 17 The main lineaments are in the nrtheastsuthwest trend, and they have shrt length in nrthern part (Chiang Khan district in Fig.1). A large number f multi-directinal lineaments are prminent, but in the ther parts a few lineaments are bserved. Main rcks f this part, including Permian sediments, Perm- Triassic vlcanics, and Triassic granites, are shwn in the gelgical map (see Fig.2 and Fig.4). Eastern Part Main lineaments in the eastern part align mstly in the nrth-suth directin. They mstly have medium length (abut 5-1 km) and are related t sme extent with the majr fld axes and the pre-existing nrthtrending thrust fault. This thrust fault is lcated at the bundary between Silurian-Devnian metamrphic rcks and Carbniferus sediments. In the vicinity f the thrust fault, several minr lineaments are bserved t cncentrate in the nrtheast-suthwest directin. It is bvius that bth the nrthwest-trending lineaments in the suth and the nrtheast-trending in the nrth crss- cut the nrth-trending lineaments. Our interpretatin n lineaments displayed in cmbinatin with the gelgical map f DMR 16 is 24' 24' 18 ' 17 12' 18 ' (a) Lei Lei 24' 18 ' 17 12' 18 ' (b) Lei Lei 24' Fig 5. (a) Lineament map using cmbined enhancement methd display by MapInf prgram, (b) Lineament map shwing nly the ORTH- trending lineaments, (c) Lineament map shwing nly the W-trending lineaments, (d) Lineament map shwing nly the Etrending lineaments ' (c) 17 12' (d) Figure 5 eawsuparp K

7 Lei River ScienceAsia 3 (24) 275 illustrated in Fig.4. LIEAMET AALYSIS Lineament analysis, which integrates the analyses f linear patterns, gemetry, kinematics and dynamics, 17 can be applied t mineral explratin in an attempt t define the mst favrable lcatins fr mineral cncentratins n the basis f tectnic cntexts. Fig. 5(a) displays all lineaments within the study area, which appear difficult t analyze because f the cmplicated features in terms f length and directin. Figs. 5 (b), (c) and (d) shw the separated directins f lineaments, trending nrth-suth, nrthwest-sutheast and nrtheast-suthwest, respectively. This scheme f wrk can be easily dne using MapInf prgram. Fr each lineament directin, the distributin, pattern, and length f lineaments are cnsidered. rth-suth Directin Fig. 5(b) display the nrth-trending lineaments distributed essentially in the eastern and western parts f the study area. distinct lineament f this directin is detected in the central part f the study area. A number f lineaments are almst parallel t the majr flds and faults described abve. The main lengths f lineaments are abut 2 km whereas sme shrt (less than 5 km) lineaments are in the zne f the thrust fault. Mst patterns f lineaments are nt straight and exhibit the swinging pattern, pssibly indicating majr fld axes in this area. The lng lineament very clse t Lei district is interpreted t represent the nrmal fault, which is cnsidered t have caused the develpment f the Lei river valley (see Figs. 5b and 6b). rthwest-sutheast Directin Fig. 5(c) depicts tw remarkably straight and cntinuus, nrthwest-trending lineaments, especially thse in the central part f the area. These majr lineaments presumably extend frm suthern Lei area t La PDR. A number f less bvius lineaments (1 km up t 2 km lng), can be bserved clearly n the image, frm the secnd-rder fractures branching t the tw majr faults. Many f the lineaments are distributed in the nrthern and suthern parts f the study area. rtheast-suthwest Directin Fig 5(d) illustrates the nrtheast-trending lineaments (5-1 km lng) that are shrter than the ther directin and becme denser than thse f the ther directins. These nrtheast-trending lineaments with an average length f 7 km are distributed thrughut the study area. The majr lineaments f this directin are cnsiderably essential since they presumably invlve in mineralizatin, which will be discussed later. DISCUSSIO Lineaments Related t Structural Tectnics In an effrt t relate lineaments with gelgical structures, we subdivide majr lineaments int cntinuus and discntinuus patterns. It is interesting that the discntinuus pattern is well recgnized nly in the eastern part f the study area. The easternmst part f the discntinuus pattern cnfrms very well with the structural feature mapped as the thrust fault by DMR 16 (see Fig. 6b). Mrever, it is essential, with Fig 6. (a) Majr and minr lineaments f the Lei study area as visualized frm the enhanced Landsat data. (b) Majr structural features deduced frm a gelgical map f DMR (1992), (c) Cmbinatin f majr lineaments and DMR majr structural features, (d) Cmbined features (Fig. c) nt DMR gelgical map. 18 ' 17 12' 18 ' (a) Cnt.majr L. Discn.majr L. Minr linear 24' Fault Thrust F. Anticline Syncline Linear A. linear 24' 18 ' 17 12' 18 ' (b) Χ σ1 24' Fault Thrust F. Anticline Syncline Χ R' Χ σ3 σ3 R Χ σ ' (c) 17 12' (d) Figure 6 eawsuparp K.

8 Lei River Lei River Lei River Lei River 276 ScienceAsia 3 (24) 18 ' Lei Au Cu Fe Ba Mn Pb 24' 18 ' Lei Au Cu Fe Ba Mn Pb 24' 17 12' (a) 17 12' (b) 18 ' Lei Au Cu Fe Ba Mn Pb 24' 18 ' Lei Au Cu Fe Ba Mn Pb 24' 17 12' (c) 17 12' (d) Fig 7. (a) Map shwing Figure verall 7 eawsuparp interpreted K lineaments and imprtant mineral ccurrences, (b) Map shwing E trending lineaments and imprtant mineral ccurrences, (c) A density -lineament map with imprtant mineral ccurrences, (d) A ttal length -lineament map with imprtant mineral ccurrences. the exceptin f the western part, that ur lineament patterns crrespnd quite well with the structural feature mapped by DMR. 16 Hwever, fr the western part, ur result n lineament analyses is useful in areas where accessibility is quite difficult and structural features are nt shwn at all in the DMR map. With a cmbinatin f the Landsat and gelgical data we can cnstruct the new structural features f this area as shwn in Fig. 6(d). The structural map by DMR, 16 revealed that majr structures in nrth-suth directin (see Fig. 6b), frm field survey prvide gd supprting evidence fr ur wrk, and that the nrth-suth lineaments deduced frm the Landsat image data cnstitutes the fault zne especially in the eastern part f the study area. Several lineaments in the study area prvide an adequate evidence f lateral displacement, and they can be cnsidered as the strike-slip (r wrench) fault. In the nrthwestern part, the majr nrth-and nrthwest-trending fault structures display significant displacement by the crss cutting nrtheast-trending strike-slip fault, suggesting that the frmer develped prir t the latter. In the nrthern part f the study area, sme large nrtheast-trending lineaments, cnsidered herein as faults, interrupt the nrth-and nrthwest trending nes withut significant ffset, and are affected subsequently by the nrth-trending nrmal faults. On the ther hand, the fault patterns in the nrtheastern part reveal that the structures with minr mvement perhaps indicate the difference in stress regimes thrugh times. Their kinematics relatinships can be described n the basis f assuming simple shear mechanisms, and using the strain ellipsid (see Fig. 6 d). Orientatin f the thrust fault and fld axes in this study area, indicate the cmpressin frce (σ1) in the east-west directin and the extensin frce (σ3) in the nrth-suth directin. The strike-slip faults in nrthwest-sutheast and nrtheast-suthwest directins are the R and R, respectively. Based n 4 Ar/ 39 Ar and Rb-Sr whle-rck ischrnal gechrnlgical data f granites in the western Thailand and eastern Myanmar, 3 nrthward drifting f western Burma blck, 19 and perhaps frm the suthern hemisphere, 2 may have caused subductin f ceanic slab beneath the amalgamated mainland sutheast Asia terrain during Middle t Late Cretaceus. Such the cmpressive tectnics may have prvided enrmus stress rughly in the nrth-suth directin t the study area. The en echeln E-trending strike-slip faults with sinistral displacement may have frmed due t this tectnic stress. The W- trending lineaments in the western part f the study area are bserved t cut acrss the Palezic strata. But these lineaments seem nt t extend int the Lei basin, at least frm surface indicatin. This may indicate that the defrmatin alng lineaments was ceased in early Cenzic. The nrthtrending thrust and the nrthwest-trending fault, which develped earlier, may have frmed due t the amalgamated terrain within mainland sutheast Asia, i.e., plate interactin f Shan-Thai 14 r Sibumasu 2 t the west, Indchina 19 and intervened plates 21 t the east. Such plate interactin, particularly eastward subductin f an ceanic slab beneath Indchina where the study area is lcated, may have given rise t the

9 ScienceAsia 3 (24) 277 emplacement f felsic t intermediate magmas. The intrusive bdies are clearly detected by previusly described circular features in the study area. The nrthtrending nrmal fault in the central part f the study area cannt be explained using circular strain ellipsid due t its much later develpment. We, therefre, cnsider that a majr change in tectnic regime may have ccurred after Cretaceus and this may crrespnd t the India-Asia cllisin 22, which may have caused the develpment f the pssibly nrmal fault-bund basin f the nrth-trending Lei river valley. Lineaments Related t Mineral Depsits Fig. 7 shws the relatinship between mineral ccurrences f nrthern Lei area and lineaments. Mst mineral ccurrences (Au, Cu, Fe, Ba, Mn and Pb) are lcated in the central part f the study area. It is clear that mineral depsits, particularly Cu, Fe and Au are significantly related t circular features nrthwest f the Lei area as shwn in Fig. 7 (a). Circular features in Thailand were earlier interpreted t represent granite intrusins prducing abundant cracks. 23 Such fractures were able t serve as channel ways fr hydrthermal and mineralizing fluids, as discussed by Sawkins, 24 Mitchell Garsn, 19 and Hutchisn. 25 Fig. 7 (b) displays the minerals ccurrences related t the nrtheastsuthwest shrt lineaments, which generally are branches f lng nrthwest-trending lineaments, especially at the lineament intersectin. We als cunt numbers f lineaments and measure their ttal length within each square-grid area f 1*1 km using the MapInf and GEOSOFT prgrams and present them as density and ttal-length lineament maps as shwn in Figs. 7(c) and 7(d), respectively. It can be assumed that, mst f mineral ccurrences are cncentrated in areas where lineaments dente bth high density and cntinuus ttal length. On the bases f these relatinships, it appears that the nrtheast-trending lineaments may serve t cntrl re mineralizatin. Fr further explratin we shuld select targets alng this directin starting at prminent intersectin, and attentin shuld be fcused in areas with high density and ttal length f lineaments, such as an area t the nrthwest crner f the map (e.g., further t Las and nearby area). COCLUSIOS Digital image enhancement prcessing is a useful tl t help analyzing space-brne image data. Interpretatin f images is a qualitative technique and shuld be tested against ther data such as the airbrne gephysical data, air-pht data and grund-truth field checks. Cmbinatin f majr lineaments frm enhanced Landsat data and structures frm this and previus gelgical maps can delineate new structural features f the area. Based upn ur lineament analysis, the suitable area fr further mineral explratin can be selected. ACKOWLEDGEMETS We thank V. Darerk, head f Department f Gelgy Chulalngkrn University and J. Tulatid, a senir gephysicist, Ecnmic Gelgy Divisin, Department f Mineral Resurces (DMR), fr their fruitful discussin n previus field and remte-sensing infrmatin, respectively. K. eawsuparp thanks S. Pthisat, the Directr General f DMR, fr his encuragement and permissin t publish this result. Thailand Remte Sensing Center, atinal Research Cuncil f Thailand (RC Bangkk) prvide all the Landsat data. Parts f this prject are spnsred by RCT, Thailand Research Fund (TRF grant n. PHD/ 17/2545), and DMR research fund. REFERECES 1. Bunpas S (1981) Palegegraphic histry f western Thailand and adjacent part f Sutheast Asia-a plate tectnic interpretatin. Ph.D. thesis, Victria University f Wellingtn, ew Zealand, 81 p. 2. Bunpas S (1988) Summary f Gelgy f Lei Area and Accmpanying 1:1, Gelgical map. Mineral Resurces Develpment Prject, Department f Mineral Resurces, Thailand, 61 p. 3. Charusiri P (1989) Lithphile Metallgenetic Epchs f Thailand: A Gelgical and Gechnlgical Investigatin. Ph. D Thesis, Queen s University, Canada, 819 p. 4. Chairangsee C, Hinze C, Macharensap S, akrnsri, Silpalit and Sinpl- Anunt S (199) Gelgical Map f Thailand 1:5,: Explanatin fr the sheets Amphe Pak Chm 5345 II, Ban a Kha 5344 I, Ban Huai Khp 5445 II, King Amphe am Sm 5444 IV. Hanver: Gelgisuhes Jahrbuch, Reihe B, 55 p. 5. Jacbsn H.S, Piersn C.T, Danusawad T, Japakaset T, Inthuputi B, Siriratanammgkl C, Prapassrnkul S and Phlphan (1969) Mineral Investigatins in rthern Thailand. Gelgical Survey Prfessinal Paper 618, Washingtn, D.C, 96 p. 6. Jantaranipa W, Vngprmek R, Sukk T. and Preammanee J (1981) Applicatin f Enhanced Landsat t Mineral Resurces f Lei Prvince, rtheastern Thailand. Ecnmic Gelgy Bulletin.3, Ecnmic Gelgy Divisin, Department f Mineral Resurces, Bangkk, Thailand, 4 p. 7. Abrams MJ, Rthery DA and Pntual A (1988) Mapping in the Oman philite using enhanced Landsat Thematic Mapper images. Tectnphysics, 151: Crsta AP and Mre JMcM (1989) Gelgical mapping using Landsat Thematic Mapper imagery in Almeria Prvince, suth-east Spain. Internatinal Jurnal f Remte Sensing, 1(3): Drury SA (1993) Image interpretatin in gelgy. 2 nd editin, Chapman Hall, Lndn, 283p.

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