Font Size: a A A

Metallogenic Prediction Based On Synthesis Information For Copper Holymetallic Deposits Concentrated Regions In The Baiyinchang Mine And Outskirts, GanSu Province

Posted on:2008-11-04Degree:DoctorType:Dissertation
Country:ChinaCandidate:G X LiaoFull Text:PDF
GTID:1100360212497776Subject:Earth Exploration and Information Technology
Abstract/Summary:PDF Full Text Request
The mineral resources is inregenerative .With the increasing of the mine exploitation fixed number of year, the single mine resources exhausted inevitable. Appearing phenomenon of resources crisis is also certainly by analyzing the mineral resources potential of mining city from single mine.But the deposits can not be exhausted if we analysize from the deposit concentrated regions and the anomaly concentrated regions, just need a process of acquaintanceship. From the anomaly concentrated regions'distributing orderliness, we can know the deposit concentrated regions'distributing orderliness, then , researching the conversion rule between their information to applying to the conceal deposit concentrated regions'prediction.The deposit is concentrated agminately, it usually can not be singleton. The deposits are existed by"a Triton of the minows", the"crane"meaning the orebeds of large-scale and supersized , the"chicken"meaning the orebeds of middle and small size.The deposit concentrated region is unit , it forms anomaly concentrated region by conversing information ,then we can lodge the new target , and progress mineral resources potential prediction. The method can also work out various prospecting problem if the method applied to crisis mine or crisis mining city.The copper is the main deposit resources in Baiyin area, produced in the baiyingchang mine.From the 50's of twenty century to this day ,the copper deposits resources of Baiyinchang mine is less and less,finding fungible or new resources becomes the most important problem at present ,therefor, to solving the problem is also the central purpose in this paper.1, Metallogenci geologic condition analysisThrough utilizing the synthesis information data of areal geology, geophysics and geochemistry in Baiyin area and with the analysis of metallogenic geologic character and mineralizing geologic condition as well as the anatomy of typical deposit, we have set up a metallogenic mode for the copper and polymetallic ores in Baiyin area. The metallogenic conditions of copper and polymetallic deposits in Baiyin area mainly are that the background of tectonic structure is the east segment of the excellent geosyncline drape zoster in the north Qinlian mountain;the conditions of magmatic rock are in the Shiqingdong-Baiyinchang lava zoster of later Proterozoic Era to Ordovician period in the north Qilian mountain,mainly distributed by blind terrene; the NWW-NW direction of regional fracture structure are the major structure factor controlling the regional geologic bodies'distribution, it have long-period activity characteristic, Sujiawan-Shiqingdong dislocation and Shuiquan-Xingquanpu dislocation are the major dislocations in Baiyin area; the horizon contributing to mineral mainly are Cambrian system quartz keratophyre tuff, typical mineral deposit is the Baiyin Copper and polymetallic deposit.the secondly horizon contributing are Sinian system and Ordovician system; the regional geophysical field incarnate lower gravitational field and higher magnetic field; regional geochemical charactetistic mainly are Copper and lead and zinc having high background numerical value,having visible concentration core and folding the high value reciprocally .Analyzed by the metallogenic geological condition, we consider that Copper and its'polymetallic deposit correlating with deep-geophysical information which is reflected by gravitational and aeromagnetic materials, the geochemical abnormality information also open out that resource potentiality is optimistic.2,The research of metallogenic prediction with synthesis informationUsing geological metallogenic theory as a prior premise, basing on summarizing and analyzing the background and geologic condition of mineralization systematically, utilizing the metallogenic prediction theories and methods with the synthesis information, at same time utilizing the relationship of the distribution between the orebeds of large-scale and supersized and the orebeds of middle and small size, the mineral sites, salinity sites and anomaly dense-set areas to set up a mineralizing model and prediction model with syntheses information, using mathematical geology and computer method to put up the research of metallogenic prediction with synthesis information in Baiyin area. We have concluded the major works and the obtained results as following:(1) The research of metallogenic series Putting out the research of metallogenic series of different type deposit in Baiyin area, we have marked off three metallogenic series and four sub-metallogenic series: jet-metamorphosed type Fe-Cu-Zn-Pb metallogenic series, kurokotype VHMS metallogenic series, saipulusi type VMS metallogenic series, magmatic hydrotherm type Au-Cu metallogenic series and malleable-brittle shear zone Au-Pb metallogenic series.(2) Geologic interpretation with the gravity and aeromagnetic informationBasing on the characters of gravity and aeromagnetics and the structures of linear that have been interpreted, as well as correlating with the distribution of known deposits, the element of geochemical anomalous, we have obtained the results that Copper polymetallic deposits and the element anomalous are controlled strongerly by the structures of linear of gravity and aeromagnetics(3) geochemical remanent anomalousSufficiently utilizing the hydrographic sediment of geochemical data and using Krieger method, F-Krieger method, SPSS methods for data processing, we have drawed out the geochemical remanent anomalous maps of every element on the MapGis platform.(4)the obtaining weight of map zoneAccording to the known copper metallogenic model and the regional metallogenic condition and indicator, we have put out the distributing map of known copper, lead, zinc deposits and fifteen metallogenic advantage weights map zone on GIS platform, proceeding the metallogenic advantage analysizing for fifteen weight map zone by using the regular definite size mesh for statistic cell,then, we have carried through the assessment of mineral resources potentiality.(5)the application of weights of evidence modelThe algorithm for weights of evidence modeling in vector GIS is used for statistics of the synthesis of multi-genetic geo-information, the space distribution map of each identification of metallogenic advantage in the whole area are used as the metallogenic advantage evidence, all evidence are synthesized according to Bayes'formula ,the synthesis of multi-genetic geo-information based on metallogenic post probability is realized in vector GIS. (6)the application of confidence model and evidence theory modelThe two reasoning methods with uncertainty,belief theory and evidence theory are applied to synthesis of multi-genetic geo-information, the mark concerned with metallogeny are used as evidence which is to affirm or negate the hypothesis of mine existence in the whole area, the probability of mine existence of each spatial location are determined, all evidence are synthesized according to the decision results so that a comprehensive decision is formed whether or not exist deposits in each spatial location of the whole area.(7)Orientation predictionWe have applied the weights of evidence model, confidence model and the evidence theory model to the future areas of coppor and polymetallic deposit in Baiyin area then synthetically contrasted the predicting results. We finally select the optimal metallogenic province and fix fifteen targets minerogenetic prospect provinces.(8) reliability validationWe have made a further reliability validation in some fixed target provinces (the targets numbers are No.1, No.2, No.3, No.4, No.8, No.9 ) through practical field geological survey which comes the following results: gossan exist widely. The second target province have the most exposed gossan At uninhabited No.8,No.9 target province we have found primary copper ore which have being exploited privately .
Keywords/Search Tags:Baiyin area, copper deposit, synthetic information, metallogenic prediction, weights of evidence model, confidence model, evidence theory model
PDF Full Text Request
Related items