Discovery of fault-grinding siliceous breccia rock in the Jiurui ore district, Jiangxi Province, and its formation mechanism and mineralization significance
-
摘要:
在九瑞矿集区研究叠合断裂和叠加成矿作用的基础上, 我们进一步详细研究了出露在洋鸡山-丁家山-望夫山一线的硅质角砾岩, 指出它们不是原先认为的石炭系沉积硅质岩, 而应属于一种断裂磨砾岩, 并深入探究其形成过程及与成矿之关系。断裂磨砾岩是断裂分带结构成熟的标志之一, 多在剪切作用和热液作用下, 断裂岩石经硅化-破裂-碎裂-粉碎-研磨, 形成具有一定圆度和球度, 大小差异较大的磨砾或磨粒, 且又会反复的集结-破碎, 不断拓宽断裂构造形成磨砾-角砾岩带。本文研究的断裂磨砾岩, 呈北东向展布, 延长达十几千米。成分上以硅化角砾岩为主, SiO2含量一般大于90%, 石英颗粒由隐晶到显晶。一些角砾岩中含Fe2O3较高, 有可能是原先的硫化物经氧化形成的褐铁矿。本区洋鸡山-丁家山-望夫山一线产出的断裂磨砾-角砾岩带, 很可能是燕山期构造-岩浆-成矿事件的产物。在城门山和武山铜矿, 我们之前的工作己发现存在产于泥盆系五通组和石炭系黄龙组层滑构造体系中的黄铁矿角砾岩, 则有可能属于海西期同生断裂活动的产物。因此, 这些不同的角砾岩具有多阶段活动和叠加成矿的特征。本文还进一步指出, 九瑞地区其他层位(如泥盆系与志留系之间、志留系与奥陶系之间)发育的层滑构造体系和断裂角砾岩及热液蚀变岩, 也很可能是成矿有利部位, 值得今后找矿工作的关注。
-
关键词:
- 磨砾 /
- 层滑系统 /
- 断层结构分带 /
- 燕山期构造-岩浆-成矿事件 /
- 九瑞矿集区
Abstract:Following our previous study on reiterative fault systems and superimposed mineralization in the Jiurui ore district (Jiang et al., 2010), in this study we conducted a thoroughly investigation on a tectonic-hydrothermal siliceous breccia rock which occurs along the NE trending Yangjishan gold mine-Dingjiashan gold mine-Wangfushan belt. Our study indicates that these siliceous breccia rocks are not sedimentary siliceous rocks in Carboniferous strata as previously thought, but belong to a fault-grinding breccia rock. The rock-forming mechanism of the breccia rocks and their relation to mineralization are also discussed in detail in this paper. Generally speaking, the fault-grinding gravel (grain) include all kinds of boudinage, grinding gravel and cataclastic flow grinding gravel, and it is an indication for maturity of fault zoning texture. Under shearing, the faulted rock may have passed stages of rupturing-fracturing-comminution-grinding and to form a great variety of grinding gravels or grains in different size with appropriate roundness and sphericity. These breccia rocks could have been repeatedly aggregated and fractured, and continuously developed to form a grinding gravel and breccia zone. In the Jiurui ore district, we found that these fault-grinding breccia rocks developed along the main NE-trending structure line of the district and extended tens kilometers long. The breccias are highly silicified with SiO2 contents > 90%. The quartz includes both cryptocrystalline and crystalline grains. Some of the breccias contain high Fe2O3 contents, which may indicate presence of primary sulfide ore breccias which have been oxidized to goethite later on. It is likely that these fault rocks were products of Yanshanian tectonic-magmatic-hydrothermal events. In the Chengmenshan and Wushan deposits, we also found various types of pyrite breccias occurring within the Devonian/Carboniferous strata and layer slip fault zone, which may have formed during the Hercynian syn-sedimentary faulting stage. All these different types of breccias composed the ore complex in the district, which show a multiple stage developing feature and superimposed mineralization characteristics. It is also suggested in this paper that the layer slip fault gravel-breccia zones in other sedimentary strata such as the Devonian/Silurian and Silurian/Ordovician at depths are potential mineralization targets that need to pay more attention in future exploration.
-
-
图 1
江西九瑞矿集区武山-洋鸡山-丁家山地区地层构造简图
Figure 1.
a sketch map of sedimentary strata and structures in the Wushan-Yangjishan-Dingjiashan area of Jiurui ore district
图 2
九瑞地区武山铜矿至洋鸡山金矿地球物理资料综合解释地质剖面图(据翟裕生等, 1999)
Figure 2.
Synthetical interpreting section by geophysical data from Wushan copper mine to Yangjishan gold mine, Jiurui district (after Zhai et al., 1999)
图 3
九瑞地区武山至城门山第Ⅲ和第Ⅳ套区域层滑系统构造剖面示意图
Figure 3.
Structural section showing the third and fourth regional layer slip systems from Wushan copper mine to Chengmenshan copper mine, Jiurui ore district
图 4
九瑞矿区洋鸡山-丁家山-望夫山断裂带巨型透镜状磨砾(岩)
Figure 4.
Giant lens grinding gravel (rock) from the Yangjishan-Dingjiashan-Wangfushan, Jiurui ore district
图 5
洋鸡山巨磨砾标本偏光显微镜下观察照片
Figure 5.
Photos of giant grinding gravel samples from the Yangjishan under polarization microscope observation
图 6
丁家山(a, b)和望夫山(c, d)巨磨砾标本正交偏光显微镜下观察照片
Figure 6.
Photos of giant grinding gravel samples from the Dingjiashan (a, b) and Wangfushan under crossed polarization microscope observation
图 7
不同研究者的剪切断层带横向分带模式
Figure 7.
Crossed zoning model of shear fault zones suggested by different researchers
图 8
洋鸡山金矿10线地质构造剖面和角砾-磨砾岩分布(据江西地质矿产勘查开发局赣西北大队, 1986 ①简化)
Figure 8.
& geological structure cross section and occurrence of breccias-grinding conglomerates in the Yangjishan gold mine along the tenth geological line
图 9
瑞昌工业园区建设工地揭露的冲断层分带结构图
Figure 9.
Thrust zoning texture exposed at a construction site of the industrialized country in the Ruichang City
图 10
城门山-武山铜矿成矿断裂带中的磨砾和磨粒
Figure 10.
Grinding gravels and grinding grains in ore-forming fault zones in Chengmenshan and Wushan copper mines
-
Ceriani S, Mancktelow NS and Pennacchioni G. 2003. Analogue modelling of the influence of shape and particle/matrix interface lubrication on the rotational behaviour of rigid particles in simple shear. Journal of Structural Geology, 25(12): 2005-2021
Chang YF, Liu XP and Wu YC. 1991. The Copper-Iron Belt of the Lower and Middle Yangtze River. Beijing: Geological Publishing House, 1-379 (in Chinese)
Chester JS, Chester FM and Kronenberg AK. 2005. Fracture surface energy of the Punchbowl fault, San Andreas system. Nature, 437(7055): 133-136
Froitzheim N, Pleuger J and Nagel TJ. 2006. Extraction faults. Journal of Structural Geology, 28(8): 1388-1395
Fusseis F, Handy MR and Schrank C. 2006. Networking of shear zones at the brittle-to-viscous transition (Cap de Creus, NE Spain). Journal of Structural Geology, 28(7): 1228-1243
Ge HP, Sun Y, Lu XC, Zhu WB, Guo JC, Liu DL and Wang CY. 2004. Discovery and analysis of ultra-micro grinding grain texture in slipping lamellae of ductile-brittle zone. Science in China (Series D), 47(3): 265-271
Gu LX and Xu KQ. 1984. The Middle Carboniferous marine volcanics and the origin of the bedded ore in Wushan, Jiangxi Province. Journal of Guilin University of Technology, 7(4): 243-251 (in Chinese with English abstract)
Gu LX and Xu KQ. 1986. On the carboniferous submarine massive sulphide deposits in the Lower Reaches of the Changjiang (Yangtze) River. Acta Geologica Sinica, 60(2): 176-188 (in Chinese with English abstract)
Hecht CA, Bönsch C and Bauch E. 2005. Relations of rock structure and composition to petrophysical and geomechanical rock properties: Examples from Permo-Carboniferous red-beds. Rock Mechanics and Rock Engineering, 38(3): 197-216
Hippertt J, Lana C and Takeshita T. 2001. Deformation partitioning during folding of banded iron formation. Journal of Structural Geology, 23(5): 819-834
Holdsworth RE. 2004. Weak faults-Rotten cores. Science, 303(5655): 181-182
Ismat Z and Mitra G. 2001. Folding by cataclastic flow at shallow crustal levels in the Canyon Range, Sevier orogenic belt, west-central Utah. Journal of Structural Geology, 23(2-3): 355-378
Jiang SY, Li L, Zhu B, Ding X, Jiang YH, Gu LX and Ni P. 2008. Geochemical and Sr-Nd-Hf isotopic compositions of granodiorite from the Wushan copper deposit, Jiangxi Province and their implications for petrogenesis. Acta Petrologica Sinica, 24(8): 1679-1690 (in Chinese with English abstract)
Jiang SY, Sun Y, Sun MZ, Bian LZ, Xiong YG, Yang SY, Luo L, Cao ZQ and Wu YM. 2010. Reiterative fault systems and superimposed mineralization in the Jiurui metallogenic cluster district, Middle and Lower Yangtze River mineralization belt, China. Acta Petrologica Sinica, 26(9): 2751-2767 (in Chinese with English abstract)
Keulen N, Heilbronner R, Stuenitz H, Boullier AM and Ito H. 2007. Grain size distributions of fault rocks: A comparison between experimentally and naturally deformed granitoids. Journal of Structural Geology, 29(8): 1282-1300
Leonov YG and Suvorov AI. 2000. Tectonic layering and tectonic motions in the continental lithosphere. Geotectonics, 34(6): 442-451
Lin AM, Miyata T and Wan TF. 1998. Tectonic characteristics of the central segment of the Tancheng-Lujiang fault zone, Shandong Peninsula, eastern China. Tectonophysics, 293(1-2): 85-104
Mao JW, Shao YJ, Xie GQ, Zhang JD and Chen YC. 2009. Mineral deposit model for porphyry-skarn polymetallic copper deposits in Tongling ore dense district of Middle-Lower Yangtze Valley metallogenic belt. Mineral Deposits, 28(2): 109-119 (in Chinese with English abstract)
Marques FO and Coelho S. 2001. Rotation of rigid elliptical cylinders in viscous simple shear flow: Analogue experiments. Journal of Structural Geology, 23(4): 609-617
Micarelli L, Benedicto A and Wibberley CAJ. 2006. Structural evolution and permeability of normal fault zones in highly porous carbonate rocks. Journal of Structural Geology, 28(7): 1214-1227
Pan YM and Dong P. 1999. The Lower Changjiang (Yangzi/Yangtze River) metallogenic belt, east central China: Intrusion-and wall rock-hosted Cu-Fe-Au, Mo, Zn, Pb, Ag deposits. Ore Geology Reviews, 15(4): 177-242
Rice JR and Guo G. 2001. New perspectives on crack and fault dynamics. Advances in Mechanics, 3: 447-460
Sibson RH. 2003. Thickness of the seismic slip zone. Bulletin of the Seismological Society of America, 93(3): 1169-1178
Stump BB and Flemings PB. 2000. Overpressure and fluid flow in dipping structures of the offshore Gulf of Mexico (EI 330 field). Journal of Geochemical Exploration, 69: 23-28
Sun Y and Shen XZ. 1983. The textural classification of fault tectonite. Chinese Science Bulletin, 28(6): 787-791
Sun Y, Shen XZ, Huang ZJ, Deng XY and Liu SH. 1984. Layer slip fractures and stratabound ore deposits: Evidence from Lower Paleozoic strata in southern Jiangsu and Anhui. Geological Reviews, 30(5): 430-436 (in Chinese with English abstract)
Sun Y and Shen XZ. 1986. A study on the zoning types of faulted rocks in China. Scientia Sinica Series B-Chemical Biological Agricultural Medical & Earth Sciences, 29(6): 663-672
Sun Y, Shi Z and Gou F. 1993. Study on mechanical parameters of rocks and regional layerslip systems in Hunan-Jiangxi areas. Science in China (Series B), 36(8): 962-975
Sun Y, Shu LS and Liu DL. 1997. On the tectonolayering, rheologicolayering and chemicolayering-yaking dipslip fault systems of the Middle-Lower Yangtze area as an example. Journal of Nanjing University (Natural Sciences), 33(1): 82-91 (in Chinese with English abstract)
Sun Y, Lu XC, Shu LS and Gu LX. 2005. Observation of ultra-microtexture of fault rocks in shearing-sliding zones. Progress in Natural Science, 15(1): 430-434
Sun Y, Shu LS, Lu XC, Liu H, Zhang XH, Lin AM and Kosaka K. 2008. Recent progress in studies on the nano-sized particle layer in rock shear planes. Progress in Natural Science-Materials International, 18(4): 367-373
Wilson B, Dewers T, Reches Z and Brune J. 2005. Particle size and energetics of gouge from earthquake rupture zones. Nature, 434(7034): 749-752
Xu KQ and Zhu JC. 2009. Origin of the Sedimentary-(or Volcanosedimentary-) Iron-Copper Deposits in some Fault Depression Belts in South China. Collection of Xu KQ Papers. Beijing: Science Press, 426-499 (in Chinese)
Yamashita T. 2003. Regularity and complexity of aftershock occurrence due to mechanical interactions between fault slip and fluid flow. Geophysical Journal International, 152(1): 20-33
Zhai YS, Yao SZ and Lin XD. 1992. The Metallogenic Features of Fe and Cu (Au) in the Middle and Lower Reaches of the Changjiang River. Beijing: Geological Publishing House, 1-235 (in Chinese)
Zhai YS, Yao SZ and Zhou ZG. 1999. Research on Orefield Tectonics of Copper and Gold Deposits in the Middle-Lower Reaches of the Yangtze River. Wuhan: China University of Geosciences Press, 1-195 (in Chinese)
Zhai YS, Wang JP, Peng RM and Liu JJ. 2009. Research on superimposed metallogenic systems and polygenetic mineral deposits. Earth Science Frontiers, 16(6): 282-290 (in Chinese with English abstract)
-
下载:
图(11)
计量
- 文章访问数: 8515
- PDF下载数: 6252
- 施引文献: 0