| Along with the development of remote sensing technologies, the comprehensivemethods by combining geophysical, geochemical,remote sensing and shallow drillingtechniques have become the comman modern mineral exploration method, under theguidance of modern geological diagenetic and metallogenic theory. It is a hot but difficulttopic to conduct large scaling remote sensing survey in forested regions. Helong area in JilinProvince is a typical forested region, where outcropping is weak and vegetation is flourished.This degrades the performance of traditional methods in the mineral exploration in Helongarea. However, Helong area is located between the eastern part of the northern margin ofNorth China Plateform and Jilin-Heilongjiang fold belt, which is a part of the importantmetallogenic-zone of eastern Jilin and Heilongjiang Province. EW and NE directionalfaults are distributed in the area. The Helong area is characterized by the intensive activity ofmagma and abundant mineral resources. The intrusive rocks include ultrabasic rock, basicrock, neutral rock and acid rock. The main mineral resources species include gold, lead, zinc,molybdenum and nickel deposits. The ore deposits are closely related to the magmatism. Sothe mineral prediction by combining geological methods with remote-sensing methods bybuilding the indicators of delineation and evaluation of anomalies in this tectonic intersectedareas, has an important guiding significance in the mineral exploration in similar areas.For this reason, the author chooses Helong area in Jilin Province as the study area. The remote sensing data of ETM, ALOS and ASTER, which are characterized by multi temporal,multiband and multi-spatial resolution, are processed and interpreted. The remote sensingimage features of all kinds of geologic bodies are determined, geological tectonic patternsare discovered, and the alteration information is extracted from the multispectral remotesensing data in the areas covered by vegetation. Finally, mineral potential prospective areasare predicted based on the comprehensive analysis of ore occurrences information, alterationinformation and geological tectonic patterns.Main achievements in the paper are listed as follows:1. Recognized the remote sensing characteristics of different geological bodies and setup remote sensing image interpretation symbols of all kinds of geological bodies.2. According to the specificity of remote sensing images of faults and brittle andductile deformation-structure, the regional geological structural patterns are recovered andthe relationship between regional structures and mineralization are investigated.3. The circular structures and their formation mechanism are recognized and therelationship between circular structure and mineralization is analyzed.4. The remote sensing alteration information is extracted from the multispectral remotesensing image data in the study area and the distribution characteristics of remote sensingalteration information are discovered. Propylitization, chloritization, serpentinization, orskarnization is mainly distributed in the porphyritic biotite granites, diorites and quartzdiorites in Permian period. Some chloritization is distributed in the metamorphic rocks inJinan group which is distributed near the south of Qingluo, western Yongchengtun, Fenchanand the west and east of Luchang in Helong County. All the alterations are mainly distributednear the faults, inner circle structures and external contact zones of intrusive bodies. Thesealterations are closely related to the mineralization. Some alterations, such as chloritization,are related to the circle structures or brittle and ductile deformation structures, anddistributed in the granites and granodiorites in Jurassic. The carbonatites are distributedsimilarly with the chloritization and both of them are distributed in the same place, somineralization anomalies may exist in the study area.5. Based on the above four results, four prospective areas are delineated. |
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