ISSN 1006-3021 CN11-3474/P
Published bimonthly started in 1979
紫金山地区中生代岩浆系统的时空结构及其地质意义
  
关键词:magmatism  temporal and spatial framework  Zijinshan area
基金项目:国家重点基础研究项目“大规模成矿作用与大型矿集区预测”(项目编号 :G1999043209)
作者单位
张德全 中国地质科学院矿产资源研究所北京100037 
李大新 中国地质科学院矿产资源研究所北京100037 
丰成友 中国地质科学院矿产资源研究所北京100037 
董英君 中国地质科学院矿产资源研究所北京100037 
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摘要:
The Temporal and Spatial Framework of the Mesozoic Magmatic System in Zijinshan Area and Its Geological Significance
      The Mesozoic magmatic system in Zijinshan area can be divided in to two subsystems, namely the Late Jurassic and the Early Cretaceous magmatic subsystems. The Late Jurassic magmatic subsystem was emplaced in upward succession at the center du- ring 157~≤141 Ma under intracontinental compression-orogeny, forming composite granite of the Zijinshan Superunit composed of medium-coarse-grained syenogranite of Jingmei Unit, medium-fine-grained monzogranite of Wulongshi Unit and fine-grained syenogranite of Jinlongqiao Unit. The fine-grained syenogranite of Jinlongqiao Unit is the differentiated lithofacies of this magmatic system, and can serve as the criteria for tin ore-prospecting in this area. The Early Cretaceous magmatic subsystem was formed during 128~94 Ma under regional extension, and exhibits a two-layer structure composed of the upper volcanic rocks and the lower intrusive rocks. During the period when volcanism was inactive (105 Ma), granodiorite porphyry invaded and was extensively buried in the depth of this area, resulting in large-scale Cu-Au mineralization. Volcanic domes and attitude of the superface of the buried granodio- rite porphyry in the Late Cretaceous magmatic subsystem can serve as the criteria for Cu-Au ore prospecting in the region. As detailed petrological study and temporal-spatial relationship show that the Chaixi monzogranite was the transitional magmatic product from the Late Jurassic magmatic subsystem to the Early Cretaceous magmatic subsystem, the age of 133 Ma of the Chaixi monzogranite should be the time record of transformation from compression to extension in this area.
ZHANG De-quan,LI Da-xin,FENG Cheng-you,DONG Ying-jun.2001.The Temporal and Spatial Framework of the Mesozoic Magmatic System in Zijinshan Area and Its Geological Significance[J].Acta Geoscientica Sinica,22(5):403-408.
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