Analysis On Multi-source Information And Metallogenic Prognosis Of Volcanic Uranium Mineralization In The Middle Section Of Daxing'Anling Mountains

In the middle section of the Daxing 'anling volcanic belt,the tectono-magmatic activity is strong and the volcanic rock is widely distribute.Previous uranium exploration and prospect prediction have been carried out in this area,and some achievements have been made.However,uranium mining in the past was mainly concentrated on abnormal zones and mineralization points,mostly "where there is a mine there is a deposit ",and the data obtained were relatively scattered,lacking systematic studies on basic geo logy and ore-forming conditions.On the other hand,previous uranium mineralization prediction work in the research area mainly focused on the regional perspective evaluation and survey selection,and mostly concentrated on qualitative analysis,lacking the use of multi-source data,especially airborne radioactive data,to carry out refined quantitative metallogenic prediction.In this paper,based on previous research results and the volcanic-type uranium mineralization theory,with the latest airborne data concentrate processing and analysis as well as comprehensive utilization of geology,mineral,aeromagnetic,remote sensing data,the author set about systematic research from two aspects.On the one hand,multisource data was used to comprehensively analyze the volcanic rock-type uranium metallogenic conditions in the middle section of Daxing'anling to evaluate the uranium metallogenic conditions of the study area;on the other,based on GIS platform,the prediction and evaluation factors were optimized to establish volcanic uranium mineralization hierarchy analysis model,and conducted quantitative mineralizaiton prediction work to analyze and evaluate the prospecting potential of the predicted propective area.The main achievements of this study are as follows:(1)The cap rock of Mesozoic volcanic basin in the middle part of Daxing 'anling mountains is mainly composed of late Jurassic acidic volcanic rocks,which are characterized by multiple cycles,multiple rhythms and multiple lithologic combinations.Uranium mineralization occurs mainly in the uranium-rich medium-acidic volcanic rocks of the Manketouebo formation,followed by the Baiyingaoolao formation and the Manitu formation.(2)Based on the summary of uranium mineralization characteristics,analysis and comprehensive study of ore-controlling factors in the study area,the volcanic type uranium mineralization in the study area is mainly controlled by the combination of NE fault,volcanic mechanism,subvolcanic rock,middle-acid volcanic rock of upper Jurassic,hydrothermal alteration and other factors.(3)Using geological,aeromagnetic and remote sensing data,a comprehensive interpretation study was carried out,the tectonic framework of the study area was systematically sorted out,and five volcanic eruption zones and 36 volcanic basins were divided.(4)On the basis of analysis of the geological characteristics and ore-controlling factors of uranium mineralization combing with analysis and extraction data from mineralization favorable information such as airborne,aeromagnetic and remote sensing data,the author drew following conclutions: 277 airborne radiocactive anomalies,388high-altitude uranium fields,985 high value halos of uranium increment,897 low value halos of active uranium,1055 high value halos of uranium potassium/thorium ratio,and966 high value halos of uranium/potassium ratio,19 regional faults and 19 volcanic mechanisms as well as over 1014 general faults and over 824 arc ring faults(20 arc ring structure groups)by remote sensing data.(5)Through the analysis of multi-source information such as geology,airborne amplifiers,aeronautical magnetism,and remote sensing data in the study area,combined with a comprehensive study of ore-controlling factors of typical uranium ore point(uranium mineralization),17 volcanic-type uranium mineralization prediction factors in the study area were determined,including uranium points,mineralization anomalies and ore volcanic rocks,regional fracture structure,volcanic structure,acidic volcanic basin,latent volcanic and hydrothermal alteration,basal stratum,airborne radiocactive anomalies,high uranium field and uranium increment(? U)high value is dizzy,activity of uranium in low(HU)is dizzy,uranium and potassium/thorium high value dizzy,uranium is higher than potassium dizzy,low-100 ? 125 nt magnetic field range,remote sensing alteration anomalies,structures by remote sensing technology.(6)Based on the GIS platform,a analytic structure model of volcanic-type uranium mineralization in the study area was established,and mineralization prediction was carried out.13 metallogenic prospects were predicted,of which one was Grade I uranium mineralization prospect and 7 Grade II uranium mineralization prospective mining areas and 5 Grade ? prospective uranium metallogenic prospecting areas,which provide references for further prospecting work.