Geological Information Extraction From RS Images And Metallogenic Predication In Northeast Of Potosi District, Bolivia

Andean mineralization belt is an important part of the circum Pacificmetallogenic belt,it’s rock metallogenic epoch is in Cenozoic.The formation of thedeposit small influenced by the externa,In remote sensing image,it can clearly reflectmetallogenic geological environment of the deposit, especially in northeast region ofBolivia’s Potosi,it is obviously zonal distributed for various types of deposits,isproduced for the eastern Cordillera fold belt and Puna plateau contact belt and its bothsides.I choose to Bolivia’s Posey area of northeast as the study area,extracte remotesensing geological information and metallogenic prediction.This article summed up regional geological data of Bolivia Potosi,applicatesETM+/ASTER remote sensing data, interpretation of linear structure, ringstructure, rock and strata geological remote sensing information, and through theremote sensing image processing technology to extract the information ofmineralization and alteration. Through these geological remote sensing information,in-depth analysis of the regional porphyry deposit ore-controlling factors and remotesensing prospecting marks, focuses on the study of typical deposit geological remotesensing characteristics, induction of porphyry type deposit geological remote sensingprospecting model,prediction understanding:1.Regional remote sensing linear structure display as nearly north-south andnorth-north-west,In remote sensing image, the south-north fracture structure displaysthat it is arranged linearly for the volcano rock,is the contact zone of the volcano rockbelt and sedimentary strata,control distribution of the formation and rock,is the mainore conducting structure in the study area; NNW trending fracture displays as thelinear valley, cuts deep,move toward stability, is transpressional faults that undercompressive stress for formation as the main ore controlling structure; in the remotesensing image, north-east-east fault that it’s small size displays as dislocation of theformation.According to the fracture cutting of the fracture,it is the latly strike-slipfault.Volcano dome of the radially inner fracture of volcano dome showed"V"shape,itcut deeply valley,is the mainly ore-bearing structures.2.In study area,the circular structure is the volcano dome that formed bymagmatic activity.In remote sensing image,it show the protruding positivelandform,annular image is obviously. the pluton that it is located the center of volcano dome is acidic porphyry,it’s time for the Neogene, porphyry and the early rockstrongly alter,formed apparent mineralization and alteration zoning. radial linearstructure of peripheral rock shows,early intrusion are emplaced by advancedintrusive,causing it to rupture.These radial fissure become favorable sites ofaggregation substance.3.The study area the eastern and northwestern of the study area have lots of foldstructure,the nuclear of the syncline structure by the Neogene and Quaternary loosedeposit composition.two strata by the Silurian and early Cretaceous sandstone andsiltstone strata composition.The sedimentary deposits and stratabound deposit of thisregional is obviously controlled by fold tectonic, showed bedding distribution.4.Using the ASTER data.It extract such alteration information by the band ratioand principal component analysis:Iron oxide type alteration, mudding type alterationand propylitization alteration.the middle of the study area,it is output parts of intrusiveand volcano lava,iron oxide type alteration is very strongly, it nearly north-southdistribute like the zonal;Mud type of alteration in the Cretaceous strata of the volcanodome and the east of a study area is very strongly;Propylitization altered distributionsame as iron oxide altered, mainly distributed in the site of the volcano lava andintermediate acid intrusive rock.5.Based on linear structure,ring structure, rock and stratum analysis andalteration information extraction of In the study area,combined with distribution ofmineral resources of the regional,it analyzed the spatial distribution of various typesof ore deposits in the study area,and discoveryed that the porphyry type deposits isobviously restricted by tectonism and magmatism, in remote sensing image,themetallogenic geological conditions can clearly, accurately interpret.So I choosepulacayo porphyry silver polymetallic deposit as a typical deposit, analysis of thegeology and the characteristics of remote sensing image, summary of metallogenicregularity of porphyry type deposit,and on this basis, establishment of geological-remote sensing prospecting model of porphyry type deposit.6.It is metallogenic forecasting for superior region of metallogenetic geologicalconditions and remote sensing prospecting of the study area,delineating the volcanodome that is located in the North approximately2km from pulacayo mining area asmetallogenic prospective area.