| 铜陵狮子山金属矿地震反射结果及对区域找矿的意义 |
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| 引用本文：.2004.Tentative Seismic Reflection Study of Shizishan Orefield in Tongling and Its Significance in Regional Exploration [J].Mineral Deposits,23(3):390~398 |
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| 基金项目:国土资源部专项研究计划(编号：20010103)，国家自然科学基金重点基金(编号：402 34051)和国土资源部“百人计划” |
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| 中文摘要:“层控”矽卡岩型矿床在长江中下游成矿带占有重要的地位，绝大多 数受控于泥盆系五通组与石炭系黄龙组的接触面。因此，长期以来“五通组砂岩+岩体”已 成为寻找此类矿床的主要找矿模型。为了探测黄龙组灰岩与五通组砂岩的接触面在铜陵矿集 区的深度和展布，为隐伏矿预测提供依据，完善金属矿区地震反射技术，笔者在铜陵矿集区 测试了3条地震反射剖面。结果显示：地震反射可以精确确定五通组顶面的分布，该控矿层 深度在1～2 km之间变化，大致呈复背斜形状，与地表的青山背斜相吻合，该层之下还存在2 个明显的岩性界面，推测分别为奥陶系灰岩顶面和基底面，其形态表现为更紧密的背斜，而 且与五通组顶板反射面形态不耦合，反映了非耦合变形过程。这种变形有利于产生层间滑脱 ，为成矿流体迁移创造了有利条件。本次试验结果表明，在地表到2 km范围内，按照“岩体 ＋赋矿层位”的找矿模型在铜陵矿集区进行深部找矿仍有巨大潜力。 |
| 中文关键词:地球物理 地震反射 分辨率 成矿系统 五通组砂岩 控矿构造 |
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| Tentative Seismic Reflection Study of Shizishan Orefield in Tongling and Its Significance in Regional Exploration |
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| Abstract:With the growing difficulty in surface mineral exploration, the prospecting for deep_seated mineral deposits has become the major strategy for exploration in th e new century, and the development of deep probe techniques is crucial for deep exploration. The seismic reflection method is of great superiority in both explo ration depth and exploration precision. However, due to the complexity of the or efield structure and the orebody shape as well as the small effective reflection area compared with the seismic wavelength, the development of mineral seismic e xploration has been limited to some extent. In recent decades, the seismic refle ction technique has made great progress, the strategy for exploration has also c hanged greatly, and the exploration of ore_related or ore_bearing structures has gradually become the major object. This strategy makes full use of the features of seismic reflection, and has acquired wide application. The results obtained have proved its effectiveness. “Stratabound" skarn type mineral deposits constitute the major type of deposits in the middle and lower Yangtze metallogenic belt. They are mainly controlled b y the contact zone between Devonian Wutong Formation and Carboniferous Huanglong Formation. Therefore, “Wutong Formation sandstone + granite” has served as th e dominant exploration model in search for this kind of mineral deposits. In ord er to detect the spatial distribution and the depth of the Wutong_Huanglong cont act zone in the Tongling ore district, provide the theoretical basis for minera l prediction, and perfect the seismic reflection technique, the authors made tes ts along 3 seismic reflection profiles in the Tongling ore district. The results show that the seismic reflection could accurately determine the distribution of the contact zone between Wutong Formation and Huanglong Formation. The depth of this ore control layer varies in the range of 1～2 km, approximately showing an anticline shape which corresponds to the surface Qingshan anticline. Below this layer, there are two clear reflections, caused probably by Ordovician limestone and the basement. They have the shape of more closed anticlines, which are deco upled with the upper reflection of Wutong Formation, thus reflecting a decouplin g deformation process. This kind of deformations is favorable to the production of decollement between the strata, which makes up a favorable condition for migr ation of metallogenic fluids. This seismic reflection experiment in Tongling ore district further proves that there are still great potential in looking for min eral deposits within the depth range of 2 km according to the “ore_bearing stra ta + granite" model. |
| keywords:geophysics, seismic reflection, resolution, mineral system, Wutong Formation sandstone, ore_coutrol structure. |
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