Prospecting for coal in China with remote sensing

JOURNAL OF CHINA UNIVERSITY OFScience DirectMININGTECHNOLOGYJ China Univ Mining Technol 18(2008)0537-0545www.elsevier.com/locate/jcumtProspecting for coal in China with remote sensingTAN Ke-long,WAN Yu-qing, SUN Sun-xin, BAO Gui-bao, KUANG Jing-shuiAerophotogrammetry and Remote Sensing Center of China Coal, Xi'an, Shaanxi710054, ChinaRemote Sensing Research Center, Shanghai University, Shanghai 200072, ChinaAbstract: With the rapid development of China's economy, coal resources are increasingly in great demand. As a result, the re-maining coal reserves diminish gradually with large-scale exploitation of coal resources. Easily-found mines which used to be identified from outcrops or were buried under shallow overburden are decreasing, especially in the prosperous eastern regions of China,which experience coal shortages. Currently the main targets of coal prospecting are concealed and unidentified underground coalbodies, making it more and more difficult for coal prospecting. It is therefore important to explore coal prospecting by taking advantage of modern remote sensing and geographic information system technologies. Given a theoretical basis for coal prospectingby remote sensing, we demonstrate the methodologies and existing problems systematically by summarizing past practices of coalprospecting with remote sensing. We propose a new theory of coal prospecting with remote sensing. In uncovered areas, coal re-urces can be prospected for by direct interpretation. In coal bearing strata of developed areas covered by thin Quaternary strata orvegetation, prospecting for coal can be carried out by indirect interpretation of geomorphology and vegetation. For deeply buriedunderground deposits, coal prospecting can rely on tectonic structures, interpretation and analysis of new tectonic clues and regularity of coal formation and preservation controlled by tectonic structures. By applying newly hyper-spectral, multi-polarization, mul-ti-angle, multi-temporal and multi-resolution remote sensing data and carrying out integrated analysis of geographic attributes,ground attributes, geophysical exploration results, geochemical exploration results, geological drilling results and remote sensingdata by GIS tools, coal geology resources and mineralogical regularities can be explored and coal resource information can bequired with some confidence.Key words: remote sensing; coal prospecting: coal field prediction; coal prospecting for deeply buried coal seams1 ntroductionremote sensing anomalies and the lack of direct interpretation for concealed coal deposits are currentlyCoal is the main energy source in China and ac- the major problemscounts for over 75% of our entire energy consump- Based on theoretical research andtion. Because of its safety and economy, coal re- cations of prospecting for coal in northwestem areassources have played a leading position in energyat often difficult accessible deserts and plateausconsumption for a long time With the economy shallow areas in the southwest and heavily covereddeveloping rapidly in China, the demand of coal re- areas in central and eastern China, we pose the quessources increases as well. But the remaining reserves tions that need to be raised for the development of theare gradually diminishing because of their large-scale next steps in coal prospecting with the aid of remotesensing in China.outcrops and those just below the surface in the developed areas of China. However, in order to pro- 2 Theoretical basis of coal prospecting bytect the fragile ecology in western China, it is neces-sary to find and explore coal with low ash and lowsulfur contents as a substitute for firewood ThereforeRemote sensing is a technology that acquires theit is an urgent problem to be resolved for resources physical parameters of the objectives through spatialinvestigation to prospect accurately, rapidly and effi- sensors by receiving electromagnetic waves reflectedciently for coal resources by using the latest technol- and dispersed from objects or electromagnetic wavesogies. Remote sensing is one of the most efficient emitted by targets. Instead of the traditional groundways for coal prospecting, but there are many factors surveys of geosciences, remote sensing technologywhich interfere with this technology. The absence of obtains ground information by pixels which evenany correlation in abnormal information existing in tall中国煤化工 nges in methods ofReceived 08 April 2008: accepted 22 June 2008Projects 1212010733809 and 1212010534601 supported by the National Geological PCNMHGCorrespondingauthorTel:+86-29-87856034:E-mailaddress:tan-kI@163.comJoumal of China University of Mining TechnologyVol 18 No 4information acquisition greatly expand the process of mudstone, shale and sandstone, whose mechanicalgeological prospecting. Remote sensing for coal strength is generally low. They are easily extruded,prospecting is the process that extracts information on demolished, weathered and exposed in crust move-the incidents of coal deposits by studying indications ments and therefore vegetation is more abundant inof prospective, coal deposits, factors which control areas of coal-bearing strata. In covered areas, vegetacoal seams and distribution rules of coalfields on the tion and geomorphological shapes may be indirectbasis of remote sensing theory and coal formation indicators of coal prospects. When mechanicaltheorystrength varies in coal bearing strata, sandstone strataCoal bearing strata are darker in hue, usually 5% to will become mountain ridges and mudstone, shale30% lower in reflectance than that of adjacent strata and coal seams will be concentrated in the foot hillsalong a standard strata profile and have a unique and form valleys. Vegetation will preferentially growspectrum. The thermal emission properties of coal are along soft rock layers. Under these circumstances, wedistinct. The thermal inertia of coal beds, compared would predict and investigate coal deposits by ana-with other rocks, is lower. Since coal absorbs more lyzing regional topography, vegetation growth andenergy. its surface temperature, emission rate and geological characteristics.radiant temperature are higher during the daytime. In 3 Remote sensing applications: researchgeneral the highest thermal anomaly appears between13: 00 and 15: 00. Lower thermal conductivity andinto coal prospectingdiffusion of coal controls its thermal radiant characteristics during the night. It releases almost all its solar takes large areas as research targets. The objective ofafter which it emanates thermal radiation mainly from tonics associated with or controlling coal seams dis-the interior of the earth crust, so that it shows lower tribution, often with a low requirement of investiga-thermal anomalies after midnight because of its lower tion accuracy.Therefore, TM, ETM, ASTER, SPOTthermal conductivityand IRS-1C images can be used in the investigationsExposed coal seams and coal-bearing strata take on at scales of 1: 200000, 1:100000 or 1:50000. Imageparticular characteristics of dark hue and layered tex- interpretation combined with field investigationsture in the visible bands of the images, which show should be carried out at first to extract anomalies as-stronger anomalies during the daytime and lower sociated with prospective coal areas and then to verithermal anomalies during the nighttime in thermalfy the anomalies with geophysical and chemical exinfrared images. Therefore, a combination of visible plorations and drilling. As is demonstrated in practice,bands and thermal infrared bands will be an effective the procedure shown in Fig. I is an economical andmethod for detecting coal prospects over exposed highly efficient way for coal prospecting with remotesensing in areas where coal bearing strata are exposedCoal bearing strata are often interbedded with to the surface or with a shallow coverta collectionGeological data[ Topographic dataData analysesFiled surveysL Preliminary interpretatiDesigning paper drafting「00000 remoteIntegrated analCompilation of 1: $000 geological mapsImage inosculation and making[ Profile measurement[ Remote sensing interpretations at scale of 1: 0000Samplingand□1:s000pngTrench exploration、mmY中国煤化工analyseCNMHGg. 1 Flow chart of prospecting for coal with remote sensingtAN Ke-lProspecting for coal in China with remote sensi3.1 Coal prospecting with remote sensing in un- geological profile measurement. Coal prospectingcovered areaswith remote sensing in these areas depends mainly onDue to the harsh geographic conditions and incon-direct interpretation, as well as analysis of regionalvenient transportation, little geological explorationstructural background and evolutionary history of thegeological basins. Interpretation of remote sensinghas been carried out in the past in the desolate, high images should be a major undertaking with assistanceand cold areas of Xinjiang, Tibet, Qinghai and gansuespecially for coal. In most of these regions this hasfrom field verification and surveys. Coal prospectingnever been done. In the desolate wastelands and pla- by remote sensing can be combined with coal geolo-teaus, where coal-bearing strata form outcrops and gy mapping at scales of 1: 50000 and 1: 25000From 1998 to 2005, ARSC, the Xinjiang Coal Ge-the structural deformation is not very severe, remote ology and Qinghai Coal Geology Bureaus discoveredensing images are very distinct and highly interpret- 26 prospective coalfields in Xinjiang, Qinghai andable. When carrying out coal prospecting with remote Tibet by remote sensing technology combined withsensing in these regions, we can analyze and studygeophysical exploration and drilling. The volumes ofthe correlations of the geological entities and remote the new found coal resources amount to about 404.41sensing images and establish directly interpretativeindicators for coal-bearing strata and geological tec. million tons in total(see Table 1)tonics through sketchy interpretation, exploration andTable 1 Exploration for coal with remote sensing in northwestem Chinad coalRegionAreaImagesDelineation of prospective coaland scalesSuccessive verificationsresources(in millionsSix areaswith a total aIn Duwa and Buya prospectiveHetian- Mingfeng8000km. One in Duwacoal bearing areas. 1: 500001: 100000 Buya, two in Nuer and one in logical mapping and drilling333+3341:14860been carried outuqia Region,ree areas, with a tou1:1000013km2driling had been carried out333+3341:14.55Southern Qinghaiof 818 km. Three in Dawu, nine dhad been carried out in 333+334: 31.76100000 in Zaduo Jiezhaand Nanqian, Dawu and Zaduo prospective coaland fourn Wulikaixinlingbearing areasSix areas, with a total area of Four areas: :50000 geologicalQinghacarried outChangdu Region,15080Seven areas, with a total area Three areas: 1: 50000 geological 333+3344: 84.921:250000of20000km2mapping and drilling had been333:860Tumen Region,5000ETM, SPOT. Four areas, with a total area Three areas: 1: 50000 geological1:100000of600kmmapping and drilling had been334143.853.2 Coal prospecting with remote sensing in tonics, physiognomy and plant cover inshallow covered areasidentify the framework for remote sensingIn southwestern China, such as in Sichuan, Guizical tectonics of the coal fields and dividhou and Yunnan provinces, coal-bearing strata aretural units. As a third step, we should anaburied in a shallow fashion and are totally overlaid bycontrol mechanisms through geological structures,Tertiary and Quaternary strata or vegetation. In spite especially the property and scale of geological struc-of these rich coal resources, the geological and phy-turees which control the basins and coal seams, thedistribution areas and causes for the formation of coalsiognomic conditions of the region are complex andthe coal usually covered by lush vegetation. The accumulation basins, investigate ancient geographyprinciple of from the known to the unknown ansynchronized depositional environment and geologifrom simple to complex "should be followed for coalcal synchronized depositional tectonics and coal ac-prospecting within these regions. First, we should cumulation regularities. Finally possible prospectiverealize the characteristics of the strata, structure, coal coal areas and coal-bearing sections should be delibearing strata, coal seams and other mineral resourcesneated. In general, prospecting for coal with remotethrough field investigations and geological profile中国煤化工 ut mainly by indimeasurement. As well. we should establish direct orgy and vegetationindirect remote sensing interpretative indicators foand tCNMHGures.From 1yy6 to 2wo, Aero-pnotogrammetry andcoal-bearing strata, coal-bearing basins and tectonics. Remote Sensing of China Coal (ARSC), the YunnanNext we should, interpret the strata; geological tec.Joumal of China Urty of Mining TechnologyVol 18 No4and Sichuan Coal Geology Bureaus had completed in southwestern China(see Table 2).successful coal prospecting work with remote sensingTable 2 Exploration for coal with remote sensing in southwestem ChinaImages andDelineation of prospective coalew gained coalR(km)bearing areasSuccessive verificationSanjiang Region,60001: 100000 Zhongdian and Four in Yong- drilling had been carried out in two 333+3341: 75.59prospective coal bearing areasRegion, Yunnan 4000 TM, RADARSAT Seven areas, with a total area of 1:5000illing had been carried out in three 333+334: 125.00Zhaotong ReETM, SPOT-2 Twelve areas, with a total area of drilling hawang. Miaoba and Xinglong pros 333+334:358.00pective coal bearing areasHuidong Region, 4000Five areas, with a total area of 1: 50000 geological mapping and145km333+3341:4639Sichuandrilling had been carried out3 Coal prospecting in deeply buried areasnew technologies for coal prospecting, starting withRelatively, more previous geological surveys have, coal-controlling structures( Fig. 2)been carried out in the central and eastern regions ofChina, where coal deposits are commonly covered bythick overlying Mesozoic and Cenozoic strata, with ageneral thickness between 200 m and 600 m, or evenover 2000 m in some parts of these regions. Pros-pecting for coal can hardly be effective with tradi-tional methods and theories. The upsurge in intermational studies of thrust and nappe tectonics occurredin the mid-1970s and research of extensional tectonics(slipping nappe structure)in the 1980s are re-garded as symbols of successful applications of platetectonic theory in continental geology-5. In practicalaspects, research on detachment structures hasopened up new areas and present new ideas in thesearch for such energy resources as coal, oil and gasas well as for other minerals. In China, the detach-ment structure theory is widely applied in studies ofcoalfield tectonics and coal exploration work, be-cause of the important status of coal in our energystructure and the structural complexity of coalfieldsGiven the impetus of new theories of coalfield gelogy, prospecting for coal in central and eastern re-gions of China should be a combination of integratedmethods that include the use of remote sensing ingeology for interpreting and analyzing target regionsand discovering profitable coal-bearing areas andblocks. These methods should also include geophys[Seismic exploration Drilling explorationcal exploration of potentially profitable coalfields andoal-bearing sections by arranging survey liFig. 2 Flow chart of coal prospecting with remoteprofitable coal-bearing areas and blocks and carry outensing in deeplyseismic exploration, core drilling for verification andother means of exploration. Of these means, re- 3.3.1search is of great importance to strengthen our under- pretat中国煤化工standing of coalfield structures and coal-controllingBystructures. We should identify the incidence of coal gy anCNMHGudy of the geolo-oncealed structureresources by applying new theories, new methods and of the base of the working area by applying remoteTAN Ke-long et alProspecting for coal in China with remote sensingsensing techniques and studying the geological and the discovery of new coal- bearing sections. The in-geophysical data, we can reveal the distribution of the terpretation of remote sensing methods in coalfieldsstructures that control the coal-bearing basin, which improves with interpreting and analyzing series ofmakes prospecting for coal more effective in con- remote sensing images at different scales and mul-cealed and half-concealed areastiple platforms. Interpretation of remote sensing ofUsing remote sensing in geological interpretation coalfields gradually developed in the direction of en-of known coal-bearing sections, combined with the larging the scale and narrowing the target area.Theintegrated analysis of geological and geophysical data, interpretation requirement of geological surveys forwe can more objectively reveal rules about coal ac- coal resources, with remote sensing at different scales,cumulation in the study area, which will assist us in is shown in Table 3.Table 3 Main application of remote sensing interpretation in coal field geology1:500000MSS Regional linear structures and Extraction of tectonics information Regional linear structure interpretation is to findfrom single band and pseudo color large-scale concealed structures and coal-t1:200000 TM Geotectonic regions, tectonic Color composition emhancement, Focused on boundary structures of coal-bearingblocks coal-bearing basinstransformationocks, and mainly based on image informaticextraction of planar objectives1:50000SPoTomponent transformation, Interpretation of thrust tectonics and analysis ofing regions and inner structures band mathccurrence conditions of coal-bearing strataWhen evaluating and applying remote sensingd) Fitting and comparing newly discovered lineartechnology in the central and eastem part of China's structures with regional geological maps and geo-concealed and half-concealed areas, we strongly urge physical exploration maps in order to determine theirthat the following interpretative work should be car- geological significance.ried out when conducting coal prospecting and coale)An analysis of the distribution characteristics,prospecting predictionchanges in direction, trends in distribution, extending1)Interpretation of main linear structureslength and continuity of the main linear structure andThe structural deformations of the earth crust dis- conduct associative characteristic studies by dividinplayed in space-borne remote sensing images are of- different planar imaging systems.ten in the form of abundant structural landscapes and Interpretation of the main linear structures revealslinear structural information. Deep structural infor- the overall process from the known to the unknownmation may also be reflected on the surface through and from image characteristics to real geological entidynamic deformation of the crust and deep geochem- ties. The interpretation maps of the major linearical reactions. In recent years, deep structural in- structures compiled with these methods can cleformation revealed by the large linear structures from reveal the general framework of regional tectonicsremote sensing images has become the subject of This can also provide a certain structural geologicalgreat interest both in China and abroad. Intes ffectretation basis for the division of secondary structural units ofand analysis of linear structures is one of the efive the region and provide basic information for improvways on studying regional geological structures. ing the compilation and survey of the coalfield geo-Linear information is a concrete manifestation of the logical map and analyzing coal controlling structures.traces left behind by surface geological structures, in2) Interpretation of thrust nappe structurewhich associated characteristics and a regional struc- In the past, the interpretation and analysis for coaltural framework have some linkages with coal con- prospecting with remote sensing largely focused ontrolling structures. Linear structural interpretation interpreting prospective areas of coal prospectingincludes:within coal-bearing basins. The study of thrust nappea)A redefinition of known fault structures, identi- structure in recent years shows that strata of differentfied by former geological work.eras are often involved in thrust faults, some of whichb)a reinterpretation and investigation of the cha. even become rootless strata. Coal-bearing strata areracteristics of known faults in remote sensing images, sometimes covered by series of foreign rock sheets.particularly those of intermittent, small linear struc- Therefore, the interpretation of thrust nappe structuretures, in order to ensure that they belong to a is also an important part of interpretation by remotelarge-scale fault, a single fault or a group of parallel sensing in those areas where thrust structures devel6) A summary of the image regulations of faultY中国煤化工nm. he struc-structures, interpreting and tracing their development turein the direction of the strike of known fault structures stratCNMH Gng strata and basalM‘Moot depth to formgiven the identity of the features of the images.shallow crust, or even crop up at the surface, which isJournal of China University of Mining TechnoloVol 18 No, 4easily identified in remote sensing images. In the rallel narrow banded imaging belt features. Thisnortheastern part of China, sporadically exposed in arc-shaped structure, as well as the linear structuresArchaeozoic rocks, Lower Paleozoic rocks and Per- among the parallel image belts, can be viewed as inmian and Carboniferous coal-bearing strata, often dications of a high angle thrust fault.parts of thrust faults or nappes are found. The Carbo- The huainan coalfield is one of the most importantniferous and Permian coal bearing strata are possibly bases of coal resources in eastern China. Originallyconcealed under the thrust faultsthe generally accepted southen boundary of theIn interpretation, thrust faults are indicated by main Huainan coalfield was always considered to be the Fulinear structures located in high positions. The linear Feng normal fault, of which the southern wall goesstructures, in the background of positive relief, gen- up while the northern wall goes down. The interpreta-erally coincide with or are parallel to ridgelines and tion of TM (Thematic Mapper) remote sensing imthere are distinct differences in planar image features ages and a survey of the Huainan region show that theon both sides of the linear structuresseries of hills at the southen margin of the Huainana)Image features of hanging walls of thrust faults: coalfield are formed by the Fu Feng-fault and thethe hanging walls of thrust faults are largely made up Shanjinjia high-angle thrust fault. It is still possibleof Archean metamorphic rocks and coal bearing for- that considerable Permian coal-bearing strata existmations or the basal strata of coal bearing formations under the nappe. As was verified later by the geolog-such as the sedimentary rocks which originated from ical team NO 147 of the Anhui Coal Geological Bu-the medium and upper Proterozoic and Paleozoic eras. reau by drilling, there are real coal seams under theThese rocks have strong weathering resistance, which overthrust nappe structure and a total of 1. 1 billionusually form positive landscapes of watersheds or tons of newly discovered prospective reserves of coalresources was gained( Fig 3)b) Image features of the bottom walls of thrust 3.3.2 Geophysical exploration, verification andfaults: the bottom walls of thrust faults are commonly ysismade up of volcanic rocks and sedimentary rocks ofI)Gravity and aeromagnetic datathe Jurassic and Cretaceous eras and are mainly dis- On the basis of appropriate computer processing ofplayed as image features of a structural basin. In gen- gravity and aeromagnetic data and through the pro.eral, image features of typical volcanic rocks are cedure of reinterpretation and re-understanding, reclearly visible at the rims of the basins. The image gional tectonic settings, especially the abundancefeatures of the banded volcanic rocks of the medium information that reflects deep structures, will be ob-Jurassic Lanqi formation are the most obviousc)Linear image features of thrust faults: coGenerally, the magnetic data can provide us withnuous linear structures are distinct boundary lines of three-dimensional, overlaying and detailed informadifferent planar zones of images, which usually show tion about the integrated magnetic bodies to a depthsome undulation and coincide with watersheds or of 20-30 km from the surface, which can directlyridgelines; they are genetically related to structural, reflect the distribution characteristics of deep maggeomorphologic feature lines such as the front of low netic bodies and clearly reveal the geotectonic traceshill tops. Non-continuous linear structure: the hang- that were eventually retained after repeated crustaling wall is usually a chain -like image belt, composed movements. Magnetic axial images can reflect theof independent hills, the bottom line of an intermit- real characteristics of crystalline basementstent scarp, an, insignificant linear structure or even anHigh values of gravitational anomalies often reflectarc-like stretch of lineuplift zones, anticline belts, raised fault blocks, horstd) Dip-angle interpretation of the thrust faultstructures or salient of crystal basements of the oldgently inclined nappe and volcanic rocks along the strata below the Paleozoic strata. Low values of gra-basin edges show parallel banded image textures, vitational anomalies reflect sedimentary basins, de-although nappes generally show images of obvious pressions, fault depressions or graben structure zonesuplifts. Indented textures of fault lines are clearly 2)Verifications by seismic exploration and drillingvisible, where steep scarps usually develop as wellThe results of remote sensing interpretation andMedium inclined thrust bodies of rocks show the im- geophysical analyses offer us coal-bearing blocks orage features of platy sheets or perfectly round rocks, sections of interest for seismic exploration and drill-showing simple linear contacts with the nappes, with ing. By making use of seismic data, we can trace thewhich they form low mountains or high hills. main coal seams and delineate their distribution andGreatly inclined thrust faults occur in groups and range, obtain the exact locations of concealed coalcontrol a complex belt of thrust faults together. The searimages of the fan-shaped uplift made up of several ures中国煤化工 cs of coal meas-arc-shaped structures are typical images of an imbri-andC N MH Gnges in thicknescate fan, controlled by the thrust faults that inclineof the major minable coal seams and interpreting thethe same direction, also accompanied by several padistribution characteristics of coal seams provideProspecting for coal in China with remote sensing543conditions for the calculation of coal resources with the most direct and reliable data and geological basis)Jiaogang lakeou countya)Remote sensing geological mapHuaihe river八e的300023(km)Prospective coalfield(b)B-B'sectionFig. 3 Remote sensing geological maps in eastern section of south wing of the Huainan coalfield3.3.3 Complex processing of multiple source geos- posing(fitting) and superimposing(overlay) and cancience informationestablish strong relations among a large number ofMultiple source information in the geosciences maps, images and data through human intervention,covers a wide range, including data obtained by sur- learn from people's strong points to offset wetveys, geological explorations, geography, geophysics, nesses elsewhere and complement each other, en-remote sensing both from the earth surface and from hancing the effectiveness of comprehensive analysithe air. Because of a lack of adequate geological data of informationand geological knowledge, impersonal knowledge ofAero-photogrammetry and the Remote Sensingthe geology of coalfields of the study area relies Bureau of China Coal carried out coal prospecting inmainly on complex analyses of geophysical informa- concealed areas of the southwestem Shandong plaintion and remote sensing information, when prospect- in 1990. We had found several groups of linear struc-ing for coal in concealed regions.ures in the directions of northeast, northwest, nearComplex processing of multiple source informa- NS(North-South)and near EW(East-West), as welltion in geosciences is a new technology in informa- astion processing that integrates computer, processing ring中国煤化工 western Shandongof digital signals, multivariate statistical analyses, provCAMH Achievements hadremote sensing and mathematics. This integrated beeprocess includes such treatment measures as com- ti-Spectral Scanner) images and 1/200000 TM(TheJournal of China University of Mining TechnologyVol 18 No 4matic Mapper)images. Under the guidelines of from interpreted by remote sensing image, the overallthe whole to the details, from the known uplift tec. structural framework and the three levels of faultstonics areas of central Shandong to the unknown tecinterpreted by aeromagnetic data basically agreetonics of concealed areas of southwestern Shandong, with the interpretation by remote sensing imagesfrom easiness to hardness, the task had been fulfilled Regional aeromagnetic anomalies can clearly reflecton the basis of the analysis of the known geological fluctuations of the depth of crystal basements, largedata, through the interpretation of concealed struc- uplifts and depressions and deep faults, which cantures with such indicators as vegetation, water system also somewhat reflect the linear structures in the diand soil moisture content anomalies of the earth's rections of the northeast and northwest that are inter-surface, as well as the computer processing of gravity,. preted by remote sensing images. With tectonic unitaeromagnetic data and complex processing of mul- division of structural levels 1, 2 and 3 and their ana-ti-source geoscience's information. Linear structures lyses of coal controlling structural types and coal bedinterpreted from gravitational anomalies and remote occurrence status, 13 predicted reliable coal-bearingsensing images can confirm each others results, Ex- zones, 9 possible coal-bearing zones and 15 inferrecept for unclear interpretations of several places, or a coal-bearing zones were identified(Fig. 4)small positional deviation from the linear structures0510kmX Buried structrue□ urst order tectonicL Snc d ordeT Third order tectonicl“叫Canalo dong沁 Cao cityFengpei fractur兴坚Fig 4 Interpretation map of tectonic units from remote sensing images in southwestern Shandong Province4 Conclusions and discussionbasins and their characteristics are mainly predictedaccording to feature images of landscapes and vegeAs investigators, we believe that remote sensing is tation cover in the areas with well develope of the most important means of coal prospectingbearing strata, thin overburden or vegetation cover.in large areas. In uncovered regions, prospective中国煤化工 ated by the imagescoal-bearing areas can be delineated by the directsolution images canof low-medium resolution satellite images, followed beCN MH Delineate concealedby large-scale coalfield geological mapping with coal bearing basins and coal bearing synclines underhigh-resolution images and drilling. Coal-bearing the overburden of concealed areas andTAN Ke-long et alal in China with resemi-concealed areas. Coal prospecting in thickly more useful information.covered areas such as the peripheries of old coal dig. Finally, methods of remote sensing in prospectinggings in central and eastern China is mainly achieved for coal should be carried out by comparative analysby tectonic interpretation, discovery of new geologi- es and interpretation analyses with a series of differ-cal tectonics and new knowledge of the rules of coal ent scales, with the applications of multi-platformcontrolling structuresremote sensing information.With the development of remote sensing technolo-2)Organic integration of RS and GISgy and its tight combination with new theories or As the spatial analysis platform of various geo-methods such as geology, geography, coal petrology, graphical attributes, surface attributes, geophysicaldigital geology, geophysics, structural geology, geo- exploration data, geochemical exploration data, geo-mechanics and modem sedimentology, remote sens- logical exploration resuits and remote sensing imageing methods for coal prospecting possess obvious data, Gis has helped to eliminate inefficient tradi-advantages with good prospects of further develop- tional analytical methods, and greatly enhanced thement,compared with traditional methods. Currently, accuracy and efficiency of comprehensive analysiChinas remote sensing method for coal prospecting and made the expression way of achievements moreshows the following aspects of a developing fieldcolorful. Most of the regions of China have abundant1)Applications of new types of remote sensing data of geological surveys, geophysical explorationtechnoloand geochemical exploration. New types of data suchSince the beginning of the 2lst century, remote as 3-D seismic and other geological exploration aresensing has entered an era of revealing much infor- also increasingly being collected in some areas. Onlyation of the surface of the earth. Both spatial reso- with comprehensive studies of various geologicallution and spectral resolution of images have im- advances, can we improve inferences and identify theproved markedly. As a surface information acquisiexistencetion tool, remote sensing consists presently of the coal-deposits and enhance prospecting for coal.following six techniques: a)multi-band remote sens- Therefore, a comprehensive analysis of all kinds ofg, b) multi-polarization remote sensing, c) information with the combination of remote sensingphase-difference remote sensing, d)multi-angle re- and GIS technology is a key process in extractingmote sensing, e) multi-temporal remote sensing, f) deep-level information of coalfields. The interdiscipmulti-pixel information integrated remote sensinglinary research of branches of geoscience obtainedIn the beginning, remote sensing for coal pros- from making use of Gis technology will graduallycting in China was carried out in too much simpli- become a new fruitful endeavorfication with limited results which usually obtained3)Integrated coal prospecting with remote sensingfrom almost only vertically multi-band images such technologyas TM images, with as consequence that much usefAs one of the means of coal prospecting, remoteinformation was suppressed. Multi-temporal, mul- sensing technology can improve the probability ofti-polarization and multi-resolution synthetic aperture coal resource discovery by combination with otherradar images can be widely applied in structural methods such as geological methods, geochemicalanalysis, topographic analysis, division of lithology methods, geophysical methods, engineering and techand stratigraphy and exploration of concealed geo- nical methods, through careful and thorough anallogical phenomena, which are somewhat difficult to ysis, analogy, induction and scientific reasoning onbe distinguished if done only by intensity images of the basis of known regional coal-forming backgroundradar. Therefore, we should explore applications of and coal-forming lawsmulti-angle remote sensing, radar remote sensing andthe integrated remote sensing with radar and optical Acknowledgementsimages in coal prospecting.Secondly, multiple resolutions and high-spectral During our research, Professor Cao Daiyong andmages provide plenty of sources of information for Mr Lin Liang of the China University of Mining andthe study of regional tectonic settings and characteris- Technology have provided us with much help andtics of surface strata at different scales, while MODis assistance in the area of prospecting deeply buriedand ASTER possess several thermal infrared bands, coal. Thanks to their valuable guidance, we havewhich can reflect the differences of surface tempera- successfully completed the research. We would alsoure, which is helpful in the analysis of concealed like to express our sincere gratitude to all of ourstructures. 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