Geochemistry and Diagenetic Pattern of Ore-Bearing Rocks about Two Types of Gold Deposit in Fengxian-Taibai Basin, South Qinling

Abstract:

Baguamiao and Shuangwang gold deposit are two important gold types in Fengxian-Taibai basin. The gold deposits are all located at the bottom of the Upper-Devonian Xing-hongpu Formation. However the ore-bearing rocks are different between them. The ore-bearing rock of Baguamiao gold deposit is ankerite rocks, which is concordant with the strata by bedded or stratoid and assume rhythmic layering form. The ore-bearing rock of Shuangwang gold deposit is albite breccias, which are mostly lens-shaped. The data of petrochemistry show that both of them are poor in Fe2O3 and K2O, which are different from normal sedimentary rocks. The elements contents of Cu, Pb and Zn are close to Clarke value. But the content of dispersed element Ge is rich in rocks, which reflect hydrothermal sedimentary origin. The characteristic of REE are different between them. The REE contents of ankerite rocks are low and elements of Ce and Eu are positive anomaly. The REE contents of albite breccias are close to regional strata and elements of Ce and Eu are middle negative. The chondrite-normalized REE patterns are also alike. It’s shown that the diagenetic fluid are high-density which been mixed by sea water slightly. So the ankerite rocks hold the REE characteristic of thermal fluid. The diagenetic fluid of albite breccias are low-density thermal fluid which been mixed by sea water intensively. It has same REE characteristic to normal sedimentary rocks.

• Periodical: Advanced Materials Research (Volumes 616-618)
• Pages: 240-245
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.616-618.240
• Online since: December 2012
• Authors: Qiang Li
• Keywords: Albite Breccias, Ankerite, Diagenetic Mode, Geochemistry Characteristic, Gold Deposit

References

[1] Liu Jianming. Dynamics of sedimentary basins and basin-fluid related ore forming[J]. Bulletin of mineralogy, petrology and geochemisty, 2000,19(2): 76-84.

[2] Liu Jianming, Ye Jie, Liu Jiajun, et al. Oil accumulation and ore formation[J]. Bulletin of mineralogy, petrology and geochemisty, 2000,19(3): 164-171.

[3] Parnell J ed. Geofluid: Origin, migration and evolution of fluids in sedimentary basin[J]. Geological Society Special Publication. London.1994, 78

[4] Bethke C M and Marshak S．Brine migration across north America－the plate tectonics of groundwater[J]. Annual Review of Earth and Planetary Sciences. 1990,18:228-315

DOI: 10.1146/annurev.ea.18.050190.001443

[5] Garven G. Continental-scale groundwater flow and geological processes[J]. Annual Review of Earth and Planetary Sciences. 1995,23:89-117

DOI: 10.1146/annurev.ea.23.050195.000513

[6] Sanford R F．A quantitative model of groundwater flow during formation of tabular sandstone Uranium deposits[J]. Econ.Geol.1994,89:341-360

DOI: 10.2113/gsecongeo.89.2.341

[7] Harison W and Summa L L. Paleohydrology of the gulf of Mexico basin[J]．American Journal of Science.1991,211:109-176

[8] Anderson R N. Sedimentary basins as thermo-chemical reactors. 1990-1991 Report[J]. Lamont-doherty Geological Obseratory,(1991)

[9] Hunt J. Generation and migration of petroleum from abnormally pressured fluid compartments[J]. AAPG Bulletin.1990,74:l-12

DOI: 10.1306/0c9b21eb-1710-11d7-8645000102c1865d

[10] Wei Longming, Wu Lieshan, Zhu Guitian, et al. Restudying on the relationship between quartz vein and gold mineralization in Baguamiao gold deposit[J]. Contributions to Geology and Mineral Resources Research,1998, 13(3):9-14.

[11] Liang Huaying, Wang Xiuzhang, Chen Jingping. Characteristics of gold-hosted stratbound albitite and forming stages of Shuangwang gold deposit in Shaanxi province[J]. Geotectonica et Metallogenia. 2000,(24)4:350-356.

[12] Rona P A, Scott S D. A special issue of seafloor hydrothermal mineralization: new perspecitive[J]. Economic Geology,1993,88(8):1935-2078

DOI: 10.2113/gsecongeo.88.8.1935

[13] Vinogradov A.P. Sredne content of chemical elements in the principal types of rocks nzverzhenyh Earth's crust [J]. Geoimiya, 1962,7:18-35

[14] Qi Huawen, Hu Ruizhong, Su Wenchao, et al. Genesis of carboniferous siliceous limestone in the Lincang germanium deposit and its relation with germanium mineralization[J]. Geochimica, 2002,31(2):161-168.

[15] Fleet A J. Hydrothermal and hydrogeneous ferromanganese deposits[A]. In: Rona P A, ed. Hydrothermal processes at seafloor spreading centers[C]. New York:Plenum Press, 1983:537-570

DOI: 10.1007/978-1-4899-0402-7_22

[16] Murray R W, Buchholtz T, Brink M R, et al. 1991. Rare earth, major, and trace elements in chert from the Franciscan complex and Montery group, California: Assessing REE source to fine grained marine sediments[J]. Geochimica et Cosmochimica Acta, V.55, 1 875~1 895.

DOI: 10.1016/0016-7037(91)90030-9

[17] Shimhzu H , Masuda A. Cerium in cherts as indicator of marine environment of its formation[J].Nature, 1977,266(24):346-348.

[18] Murray R W, Brink M R B, Gerlach D C, et al. 1990. Rare earth elements as indicatiors of different marine depositional environments in chert and shale[J]. Geology, 18(3): 268~271.

DOI: 10.1130/0091-7613(1990)018<0268:reeaio>2.3.co;2

[19] Lu Huanzhang. Ore-forming fluids[M]. Beijing: Geological Publishing House,1997.120-131.

[20] Zhang Zuoheng, Mao Jingwen, Li Xiaofeng. Geology, geochemistry and metallogenic mechanism of Shuangwang breccia type gold deposit[J]. Mineral deposits, 2004,23(2):241-252.