铜陵矿集区浅层隐伏岩体预测及其形态分析

Prognosis and Morphological Analysis of Subsurface Concealed Magmatic Bodies in Tongling Ore Concentration Area

作者通过分析不同地形_地质界面间的差值域分布特征 ,对浅层隐伏岩体进行了数值模拟和产状预测。模拟结果显示铜陵矿集区有可能存在着一个顶点朝下的圆锥状岩浆构造 ,从整体上看 ,该隐伏岩体在深处收缩为一个点源 ,从该点源往上分布范围逐渐扩大 ,岩体也开始发生分叉现象 ,使靠近或出露于地表的分支岩体在产状上更接近于小型岩枝。推断它有可能是连接深_浅部之间的岩浆“汇” ,该岩浆“汇”将来自更深部岩浆源的含矿物质和热能转送到更浅部的各分叉岩枝内 ,并因此成为铜陵矿集区成矿物质的重要来源和能量来源。

The gravity aeromagnetic anomaly and the specific structural assemblage shown in TM images indicate the existence of a shallow concealed magma chamber in the center of Tongling area. Nevertheless, the 3D shape of the concealed magma chamber and its spatial relation with the outcropped apophyses are still not clear. Based on field and drill hole data obtained from Tongling area, the authors carried out a numerical simulation to probe into the difference domain between two strata or between the strata and the topographic surface. Moreover, the difference domain that represents the space filled with the magmatic body was applied to predict the subsurface concealed magmatic bodies and analyze their spatial structures. The results of the numerical simulation show the existence and the 3D shape of a hidden conical magmatic structure beneath the middle of this area. Its top bifurcates southwards into several branches, while its lower part stretches northeastwards and contracts rapidly to one point. This point is considered to be the 'sink' of the concealed magmatic system, which transfers ore materials and heat energy from the deeper magma chamber to the subsurface apophyses.