| The thesis is finished by the favor of the project "the resources survey of iron and copper mine in the periphery of Dahong Mountain, Xinping village, Yunan provience". This thesis traverses the petrologic features and petro chemistry characteristics of sub volcanic rock and cryptoexplosive breccia in Dongme mining area of Dahong Mountain trough a series of ways. Firstly, to build the theoretical basis through comprehensive analysis of regional geological background, geological and mineralized features of the mining area; then to collect ore samples through field survey and profile survey; to get the results through microscopic identification of samples at last. The main points of the thesis are as follows:1.Through the study of several typical profiles and relevant rock, ore and geological materials which are gotten from misering in Dongme and Diba mining area, the results show that the exploded breccias mainly appear in Dongme mining area and the reason can’t be explained for now; and it always co-occur with meta gabbroic-diabase, its’surrounding rock is marble but its’ occurrence with surrounding rock can’t be seen that conjecture to form mainly by the influences of regional structure after diagenesis.2.The components of cryptoexplosive breccia are not only from the dacite breccias which are brought by the magma itself and albite breccias which are strongly altered lately but also come from actinolite breccias which are relevant with surrounding rocks and basic igneous complex. The quartz phenocryst in rock present like broken porphytitic,feldspar crystals fractured, the biotite phenocrysts was distorted like flaming and its’cement composition and breccaited ingrsdients are similar. The rocks are strong hydrochloric salinization, albization magnetite crystals and the magnetite crystals and are in close paragenesis with the albitization’s rock.3.During the study, we selected two sections of rock samples and drill core samples at the Dong-mo mine. Combined with the chemical analysis and the microscopic identification results, it is confirmed that minerals is in the form of two type samples, one of minerals play the role of marble carrier, Fe enriched by breccia replacement of the original rock, minerals are brecciaous. Another ore carrier is the parent rock of the ore, the ore enriched themselves. Marble is the surrounding rock of the ore. After chemical analysis of major elements from the rocks, the author found minerals contain similar compounds of explosion breccia and sub-volcanic rock composition. We confirmed their ore-forming matters come from the same source.4.By analyzing REE, we knew LREE of Dong-mo mine is poor, it is similar to the Da-hong-shan area. LREE/HREE ratio is0.847to4.739. It contains high cerium group rare, poor yttrium group rare.5.Through the diagenetic mechanism study of explosion breccia, I believe that formation of explosion breccia is closely related to the Ai-lao Mountain. Ai-lao Mountain orogeny provides magma migration pathways and diagenetic space for explosion breccia.6. cryptoexplosive breccia is an important ore guide of blind ore bodies, as well as, explosion breccia can also be referred to the ore carrier. The explosion breccia could provide great significance in finding new deposits in Da-hong-shan. |
PDF Full Text Request