RELATIONSHIP BETWEEN DĜCOLLEMENT-EXTRUSION TECTONICS AND GOLD DEPOSITS IN ADJOINING AREA OF SICHUAN, GANSU AND SHAANXI PROVINCES
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摘要: 分析了陕甘川邻接区滑脱挤出构造与金矿床的空间关系、时间关系及其对地球化学元素活化迁移作用.认为陕甘川邻接区的大型、特大型金矿主要受第二和第一次级滑脱带控制, 为该区金矿远景区的预测提供了构造依据.Abstract: The authors analyzed the space and time relationship between the décollement-extrusion tectonics and the gold mineralization in the adjoining area of Sichuan, Gansu and Shaanxi provinces and its effect on the activity and migration of geochemical elements in the décollement shear zone. The large and super-large gold deposits are all controlled mainly by the secondary- and primary-order décollement zones in the area. This reseach result provides us with the structural basis for the forecasting of gold-mine prospective location in this area.
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Key words:
- extrusion tectonics /
- gold deposit /
- Sichuan, Gansu and Shaanxi provinces
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图 2 四川松潘东北寨金矿地质略图(a) 及矿体剖面图(b) (据李小壮[10])
1.第四系残坡积层; 2.上三叠统板岩; 3.中三叠统砂板岩; 4.下三叠统砂板岩夹灰岩; 5.下二叠统灰岩; 6.中上石炭统灰岩; 7.下石炭统泥灰岩; 8.矿体及编号; 9.构造蚀变带范围; 10.垮石崖逆冲断层; 11.斜向平移断层
Fig. 2. Geological sketch (a) and the profile of ore-body (b) of the Dongbeizhai gold deposit, Songpan County, Sichuan Province
图 4 甘肃大水金矿田地质图②
1.第四系; 2.白垩系田家坝组; 3.侏罗系龙家沟组; 4.三叠系隆务河组; 5.迭山组五段; 6.迭山组四段; 7.迭山组三段; 8.迭山组二段; 9.迭山组一段; 10.花岗闪长斑岩; 11.花岗闪长岩脉; 12.斑状黑云母闪长玢岩; 13.闪长玢岩脉; 14.泥质灰岩; 15.方解石脉; 16.金矿体; 17.不整合地质界线; 18.岩相界线地质界线; 19.构造角砾岩带; 20.实测推测平移断层; 21.实测断层; 22.大理岩化; 23.挤压劈理; 24.Rb-Sr法年龄
Fig. 4. Geological map of Dashui gold field, Gansu Province
图 5 陕西略阳铧厂沟金矿床地质平面图(据党明福[11]改编)
1.第四系; 2.中下泥盆统三河口群二岩段; 3.中下泥盆统三河口群—岩段; 4.中上元古界碧口岩群; 5.细碧岩; 6.金矿体; 7.细晶灰岩; 8.石英砂岩; 9.压扭性断裂
Fig. 5. Geological map of the Huachanggou gold deposit, Lueyang County, Shaanxi Province
表 1 徐古构造地球化学剖面元素质量分数与大陆地壳丰度的对比
Table 1. Comparison between the element mass fractions in the tectono-geochemical section in Xugu, Heishui County, Sichuan Province and the abundance in continent crust
表 2 徐古构造地球化学剖面元素均值与标准离差
Table 2. Mean value and the standard deviation of elements in the tectono-geochemical section
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[1] 曾佐勋, 曹树钊. 赣西北港口-马坳地区的滑脱构造基本特征[J]. 江西地质, 1994, 8(4): 309-319. https://www.cnki.com.cn/Article/CJFDTOTAL-JXDZ404.006.htm [2] 曾佐勋, 杨巍然, Franz Neubauer, 等. 造山带挤出构造[J]. 地质科技情报, 2001, 20(1): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201004022.htm [3] Tapponnier P, Molnar P. Slip-line fields theory and large-scale continental tectonics[J]. Nature, 1976, 264: 319-324. doi: 10.1038/264319a0 [4] Ratschbacher L, Merle O, Davy P H, et al. Lateral extrusion in the Eastern Alps, Part 1: boundary conditions and experiments scaled forgravity[J]. Tectonics, 1991, 10: 245-256. doi: 10.1029/90TC02622 [5] Ratschbacher L, Frisch W, Linzer H G, et al. Lateral extrusion in the Eastern Alps, Part 2: structural analysis[J]. Tectonics, 1991, 10: 257-271. doi: 10.1029/90TC02623 [6] Burchfiel B C, Royden L H. North south extension within the convergent Himalayan region[J]. Geology, 1985, 13: 679-682. [7] Hodges K V, Burchfiel B C, Royden L H, et al. The metamorphic signature of contemporaneous extension and shortening in the central Himalayan orogen: data from Nyalam transect, southern Tibet[J]. Journal of Metamorphic Geology, 1993, 11: 721-737. doi: 10.1111/j.1525-1314.1993.tb00183.x [8] Grujic D, Casey M, Davidson C, et al. Ductile extrusion of the Higher Himalayan Crystalline in Bhutan: evidence from the quartz microfabrics[J]. Tectonophysics, 1996, 260: 21-43. doi: 10.1016/0040-1951(96)00074-1 [9] 许志琴, 杨经绥, 姜枚, 等. 大陆俯冲作用及青藏高原周缘造山带的崛起[J]. 地学前缘, 1996, 6(3): 139-151. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY199903018.htm [10] 李小壮. 四川东北寨金矿的主要地质特征及控矿条件[A]. 见: 地质矿产部秦巴科研项目办公室和陕西省地质矿产局秦巴金矿科研办公室, 编. 秦巴金矿论文集[C]. 北京: 地质出版社, 1993, 178-189. [11] 党明福. 陕西省略阳县铧厂沟金矿地质特征[J]. 陕西地质, 1991, 9(1): 18-29. https://www.cnki.com.cn/Article/CJFDTOTAL-SXDY199101002.htm [12] 曾佐勋. 陕甘川邻接区滑脱挤出构造[D]. 武汉: 中国地质大学, 2000. [13] Taylor S R, McLennan S. The continental crust: composition and evolution[J]. Blackwell scientific publication, 1985, 54: 209-230. [14] 曾佐勋, 周继彬, 刘立林, 等. 陕甘川邻接区基于MAPGIS的金成矿远景区预测[J]. 地学前缘, 2001, 8(2): 415-420. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY200102034.htm