| This research, which is based on the project of "The Potential Mineral Resource Evaluation In The Autonomous Region of Tibet ", mainly focusing on processing, anglicizing and interpreting the gravity and magnetic data from this project. Firstly a detailed discussion was carried out in this paper based on the previous theoretical system and associated with the latest results of regional geology and mineral resources survey in Tibet, including regional stratigraphy, geology structure, regional magnetic activities, metamorphism and tectonic evolution. By taking three comparatively typical lead-zinc deposit of the epithermal-type, the skarn-type, the carbonate-type lead-zinc deposit as examples, the writer used the raw, processed data of aeromagnetic to study the magnetic anomaly characteristics and inversion data, and predict the typical ore deposits. In this paper the author analysis the characteristics of geological structure and the features, make a distribution of lead-zinc deposit and aeromagnetic characteristics in the Autonomous Region of Tibet.In this research, the author takes the regional aeromagnetic data in the scale of1:100000as the raw material to process, converse and analysis, main methods including the Horizontal First-Derivative and the Directional Derivative of Aeromagnetic, the Upward Continuation etc. At the same time, the writer makes a detailed analysis that the characteristics of magnetic anomaly in three typical lead-zinc forecast deposits, using the regional aeromagnetic data in the scale of1:250000as the raw data to process and converse, and then conducts conclusions of geological structure by magnetic method. The regions with rich lead-zinc deposit in Tibet are:The Sanjiang area of eastern Tibet is a merging composite orogenic belt of some stable block and three island arc of the collusion orogenic belt with violent magmatic activities, almost constructed with intermediate-acidic intrusive rocks. In this area, the deep faults, the structures of the drape controlled the deposition and magmatic activities all are closely related to mineralization, which is an important ore-controlling structure system.Gangdese belt in Tibet is jointing with "Sanjiang" tectonic belt and Pamils Karakoram tectonic belt in the southwest, the Yarlungzangbo suture and Bangong-nujiang suture form the north to the south. Special tectonic structures, frequent tectono-magmatic activities and times-stack of metallogenic, produced a number of different metallogenic system, provide the formed inner conditions of the metallogenic deposits in Gangdese belt.The research shows that there are numerous lead-zinc minerals in Tibet. The types of ore deposits are variety and the causes of formation are different. The epithermal-type lead-zinc mine is a typical deposit which is formed by the epithermal-type ore in favorable structural and rocks. The deposit control s by structural obviously, the gradient of the aeromagnetic data changed quickly and the trend of aeromagnetic zones is roughly consistent with distribution of the fracture and epithermal-type rock. The limestone formation in Skarn-type is one of the first signs to prospect the lead-zinc deposit, the ore body is formed in the limestone bedding which is more brown in color. The skarn that containing mining ore is relevant to the broken layers, often located on the edge of the magnetic anomaly traps, obviously indicated in aeromagnetic anomalies. The specialties of Carbonate-type lead-zinc deposits are deposition and stratabound metallogenic. The geological deposit occurred in a certain layer, the reflections on magnetic anomaly are not obvious, so for a clear conclusion it’s better to make further investigation on related geological information. |
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