毕业论文毕业设计地质外文文献翻译中英文对照_精品.doc

中国地质大学长城学院 地质英语论文 系 别 地球科学与资源系 专 业 资源勘查工程 学生姓名 学 号 指导教师 2012年12月16日 Title:Orthomagmatic ore deposits One.Orthomagmatic ore deposits The magma contains a certain number of metal and volatile components of the silicate melt. All kinds of magma after crystallization and differentiation, make the forming materials dispersed in the magma gathered and formed deposits.And this deposits is called magmatic deposits. Magmatic deposits formed in the magmatic stage, the source of the material of the deposit is the main ore-bearing magma. Magmatic deposits is the product of the magma by crystallization and differentiation, and generally have the following properties: Deposits have the mainly relationship with the mafic and ultramafic rocks.And a small number of magmatic deposits with alkaline rocks or magmatic carbonatite-related. Mineralization and diagenesis often begin at the same time.And this is typical of syngenetic ore deposits. Few mineralization of the magmatic deposits may be continued to a later time, but generally does not exceed a total period of magmatic activity. The magmatic deposits ore body majority present stratiform,stratiform, lenticular and podiform and so on.And they produced in the magma body,and the wall rock of containing ore is the mother rock.Few cases,orebody presenting vein and stockwork enter the wall rock which outside of the mother rock.Between the ore body and the wall rock generally is gradual change or rapid gradual change relationship,.Only penetration magmatic deposits have the clear boundaries with the wall rock. Except the rare and rare earth elements deposits of the magmatic carbonatite due to special causes have some alteration about the wall rock,the vast majority of magmatic deposits surrounding