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Characteristics and formation processes of (Ba, K, NH4)-feldspar and cymrite from a lower Cambrian black shale sequence in Anhui Province, South China

Published online by Cambridge University Press:  28 February 2018

Chao Chang
Affiliation:
State Key Laboratory for Mineral Deposits Research, Institute of Energy Sciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, China
Wen-Xuan Hu*
Affiliation:
State Key Laboratory for Mineral Deposits Research, Institute of Energy Sciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, China
Qi Fu
Affiliation:
Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77204, USA
Jian Cao
Affiliation:
State Key Laboratory for Mineral Deposits Research, Institute of Energy Sciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, China
Xiao-Lin Wang
Affiliation:
State Key Laboratory for Mineral Deposits Research, Institute of Energy Sciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, China
Ye Wan
Affiliation:
State Key Laboratory for Mineral Deposits Research, Institute of Energy Sciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, China
Su-Ping Yao
Affiliation:
State Key Laboratory for Mineral Deposits Research, Institute of Energy Sciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, China
*

Abstract

Barium-rich silicates were recently found in the lower Cambrian black shale sequence of Anhui Province, South China. The Ba silicates can be divided into Ba-poor K-feldspar, Ba-rich K-feldspar and cymrite, on the basis of occurrence and composition. The Ba-poor K-feldspar have low BaO contents (<1.00 wt.%) and occur as sporadic grains in mudstone. In contrast, the Ba-rich K-feldspar have higher BaO contents (1.36–20.51 wt.%) and occur mainly as rims around grains of Ba-poor K-feldspar in mudstone, as void fillings in dolostone, and as grains dispersed in chert. The cymrite is observed only in chert and occurs as dispersed euhedral tabular crystals. Analyses of the Ba-poor K-feldspar and Ba-rich K-feldspar provide compositions that total <100 wt.% and show non-stoichiometry characterized by (Na + K + Ba + Ca)apfu less than 1.00 and (Al + Si)apfu slightly higher than 4.00. Raman and infrared (IR) spectroscopy has revealed the presence of ${\rm NH}_{\rm 4}^{\rm +} $ and H2O in the Ba-rich K-feldspar, which accounts for the unusual composition of these feldspars. We suggest that the formation processes of the Ba-poor K-feldspar, Ba-rich K-feldspar and cymrite were closely associated with multi-stage hydrothermal fluids enriched in Ba and NH4, consistent with an extensional tectonic setting during the early Cambrian. The Ba-poor K-feldspars might have formed through interactions between pre-existing K-feldspars and hydrothermal fluids. The Ba-rich K-feldspars in mudstone and dolostone formed mainly by precipitation from hydrothermal fluids that infiltrated the sediments, and we suggest the Ba-rich K-feldspars and cymrite in the chert are of exhalative hydrothermal origin.

Type
Article
Copyright
Copyright © Mineralogical Society of Great Britain and Ireland 2018 

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Footnotes

Associate Editor: Martin Lee

References

Back, M.E., Mandarino, J.A. and Fleischer, M. (2008) Fleischer's Glossary of Mineral Species, Mineralogical Record Incorporated, USA.Google Scholar
Boyd, S.R. and Philippot, P. (1998) Precambrian ammonium biogeochemistry: a study of the Moine metasediments, Scotland. Chemical Geology, 144, 257268.Google Scholar
Bucher, K. and Grapes, R. (2011) Petrogenesis of Metamorphic Rocks, Springer Berlin Heidelberg.Google Scholar
Chabu, M. and Boulegue, J. (1992) Barian feldspar and muscovite from the Kipushi Zn–Pb–Cu deposit, Shaba, Zaire. Canadian Mineralogist, 30, 11431152.Google Scholar
Chang, C., Hu, W.X., Fu, Q., Cao, J., Wang, X.L. and Yao, S.P. (2016) Characterization of trace elements and carbon isotopes across the Ediacaran-Cambrian boundary in Anhui Province, South China: Implications for stratigraphy and paleoenvironment reconstruction. Journal of Asian Earth Sciences, 125, 5870.CrossRefGoogle Scholar
Chen, D.Z., Wang, J.G., Qing, H.R., Yan, D.T. and Li, R.W. (2009) Hydrothermal venting activities in the Early Cambrian, South China: Petrological, geochronological and stable isotopic constraints. Chemical Geology, 258, 168181.Google Scholar
Coats, J., Smith, C., Fortey, N., Gallagher, M., May, F. and McCourt, W. (1980) Strata-bound barium–zinc mineralization in Dalradian schist near Aberfeldy, Scotland. Transactions of the Institution of Mining and Metallurgy Section B-Applied Earth Science, 89, B110B122.Google Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (2001) Rock-Forming Minerals, Volume 4A: Framework Silicates. The Geological Society, London, England.Google Scholar
Essene, E.J., Claflin, C.L., Giorgetti, G., Mata, P.M., Peacor, D.R., Arkai, P. and Rathmell, M.A. (2005) Two-, three- and four-feldspar assemblages with hyalophane and celsian: implications for phase equilibria in BaAl2Si2O8–CaAl2Si2O8–NaAlSi3O8–KAIS3O8. European Journal of Mineralogy, 17, 515535.Google Scholar
Fortey, N.J. and Beddoestephens, B. (1982) Barium silicates in stratabound Ba–Zn mineralization in the Scottish Dalradian. Mineralogical Magazine, 46, 6372.CrossRefGoogle Scholar
Freeman, J.J., Wang, A., Kuebler, K.E., Jolliff, B.L. and Haskin, L.A. (2008) Characterization of natural feldspars by Raman spectroscopy for future planetary exploration. Canadian Mineralogist, 46, 14771500.Google Scholar
Gay, P. and Roy, N.N. (1968) The mineralogy of the potassium-barium feldspar series III: Subsolidus relationships. Mineralogical Magazine, 36, 914932.CrossRefGoogle Scholar
Graham, C.M., Tareen, J.A.K., Mcmillan, P.F. and Lowe, B.M. (1992) An experimental and thermyodynamic study of cymrite and celsian stability in the system BaO–Al2O3–SiO2–H2O. European Journal of Mineralogy, 4, 251269.CrossRefGoogle Scholar
Han, S., Hu, K. and Cao, J. (2013) First discovery of zoned hyalophane in the barite deposits hosted in Early Cambrian black shales of South China and its geological implications. Geological Review, 59, 11431149.Google Scholar
Henry, D.J., Will, C.N. and Mueller, P.A. (2015) Ba-rich K-feldspar from mafic xenoliths within Mesoarchean granitic rocks, Beartooth Mountains, Montana, USA: Indicators for barium metasomatism. Canadian Mineralogist, 53, 185198.Google Scholar
Honma, H. and Itihara, Y. (1981) Distribution of ammonium in minerals of metamorphic and granitic-rocks. Geochimica et Cosmochimica Acta, 45, 983988.Google Scholar
Hsu, L.C. (1994) Cymrite: new occurrence and stability. Contributions to Mineralogy and Petrology, 118, 314320.Google Scholar
Jakobsen, U.H. (1990) A hydrated barium silicate in unmetamorphosed sedimentary-rocks of Central North Greenland. Mineralogical Magazine, 54, 8189.CrossRefGoogle Scholar
Jiang, S.Y., Yang, J.H., Ling, H.F., Chen, Y.Q., Feng, H.Z., Zhao, K.D. and Ni, P. (2007) Extreme enrichment of polymetallic Ni–Mo–PGE–Au in lower Cambrian black shales of South China: An Os isotope and PGE geochernical investigation. Palaeogeography Palaeoclimatology Palaeoecology, 254, 217228.Google Scholar
Large, D. (1980) Geological parameters associated with sediment-hosted, submarine exhalative Pb–Zn deposits: an empirical model for mineral exploration. Geologisches Jahrbuch, D40, 59129.Google Scholar
Long, H., Long, J., Zhong, Y., Zhuang, S. and Liu, T. (1994) Discovery of hyalophane from the Vanadium deposit in the black rock series at Zhangcun–Zhengfang: Evidence for hydrothermal sedimentary origin. Chinese Science Bulletin, 39, 636638 [in Chinese].Google Scholar
Matsubara, S. and Kato, A. (1991) Edingtonite from the Shiromaru mine, Tokyo, Japan. Ganko, 86, 273277.Google Scholar
McSwiggen, P.L., Morey, G.B. and Cleland, J.M. (1994) Occurrence and genetic-implications of hyalophane in manganese-rich iron-formation, Cuyuna-Iron-Range, Minnesota, USA. Mineralogical Magazine, 58, 387399.Google Scholar
Moro, M.C., Cembranos, M.L. and Fernandez, A. (2001) Celsian, (Ba,K)-feldspar and cymrite from sedex barite deposits of Zamora, Spain. Canadian Mineralogist, 39, 10391051.CrossRefGoogle Scholar
Nyquist, R.A. and Kagel, R.O. (1971) Infrared Spectra of Inorganic Compounds. Academic Press, New York and London.Google Scholar
Orberger, B., Gallien, J.P., Pinti, D.L., Fialin, M., Daudin, L., Grocke, D.R. and Pasava, J. (2005) Nitrogen and carbon partitioning in diagenetic and hydrothermal minerals from Paleozoic Black Shales, (Selwyn Basin, Yukon Territories, Canada). Chemical Geology, 218, 249264.Google Scholar
Parker, J.H., Feldman, D.W. and Ashkin, M. (1967) Raman scattering by silicon and germanium. Physical Review, 155, 712714.Google Scholar
Raith, M., Devaraju, T. and Spiering, B. (2014) Paragenesis and chemical characteristics of the celsian−hyalophane−K-feldspar series and associated Ba–Cr micas in barite-bearing strata of the Mesoarchaean Ghattihosahalli Belt, Western Dharwar Craton, South India. Mineralogy and Petrology, 108, 153176.Google Scholar
Reinecke, T. (1982) Cymrite and celsian in manganese-rich metamorphic rocks from Andros Island-Greece. Contributions to Mineralogy and Petrology, 79, 333336.Google Scholar
Russell, M., Hall, A., Willan, R., Allison, I., Anderton, R. and Bowes, G. (1984) On the origin of the Aberfeldy celsian + baryte + base-metal deposits, Scotland. Pp. 159170 in: Prospecting in Areas of Glaciated Terrain 1984. Institution of Mining and Metallurgy, London.Google Scholar
Sakamoto, J., Hashimoto, S., Tsuda, T., Sugahara, T., Inoue, Y. and Ohgaki, K. (2008) Thermodynamic and Raman spectroscopic studies on hydrogen plus tetra-n-butyl ammonium fluoride semi-clathrate hydrates. Chemical Engineering Science, 63, 57895794.Google Scholar
Sorokhtina, N., Chukanov, N., Voloshin, A., Pakhomovsky, Y.A., Bogdanova, A. and Moiseev, M. (2008) Cymrite as an indicator of high barium activity in the formation of hydrothermal rocks related to carbonatites of the Kola Peninsula. Geology of Ore Deposits, 50, 620628.CrossRefGoogle Scholar
Smith, J.V. and Brown, W.L. (1988) Feldspar Minerals, Volume 1: Crystal Structures, Physical, Chemical, and Microtextural Properties. Springer, Berlin, Heidelberg.Google Scholar
Stefov, V., Soptrajanov, B., Kuzmanovski, I., Lutz, H.D. and Engelen, B. (2005) Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. III. Spectra of protiated and partially deuterated magnesium ammonium phosphate hexahydrate. Journal of Molecular Structure, 752, 6067.Google Scholar
Steiner, M., Wallis, E., Erdtmann, B.D., Zhao, Y.L. and Yang, R.D. (2001) Submarine-hydrothermal exhalative ore layers in black shales from South China and associated fossils – insights into a Lower Cambrian facies and bio-evolution. Palaeogeography Palaeoclimatology Palaeoecology, 169, 165191.Google Scholar
Viswanathan, K. and Kielhorn, H.M. (1983) Variations in the chemical-compositions and lattice dimensions of (Ba,K,Na)-feldspars from Otjosondu, Namibia and their significance. American Mineralogist, 68, 112121.Google Scholar
Wang, J. and Li, Z.X. (2003) History of Neoproterozoic rift basins in South China: implications for Rodinia break-up. Precambrian Research, 122, 141158.Google Scholar
Wang, J.G., Chen, D.Z., Wang, D., Yan, D.T., Zhou, X.Q. and Wang, Q.C. (2012) Petrology and geochemistry of chert on the marginal zone of Yangtze Platform, western Hunan, South China, during the Ediacaran–Cambrian transition. Sedimentology, 59, 809829.Google Scholar
Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185187.Google Scholar
Xia, F., Ma, D., Pan, J., Chen, S., Cao, S., Sun, Z., Liu, C. and Guo, G. (2005) EMP study of early Cambrian barite deposits in Eastern Guizhou, China. Acta Mineralogica Sinica, 25, 289294.Google Scholar
Yang, A., Zhu, M., Zhang, J., Zhao, F. and Lv, M. (2015) Sequence stratigraphic subdivision and correlation of the Ediacaran (Sinian) Doushantuo Formation of Yangtze Plate, South China. Journal of Palaeogeography, 17, 120.Google Scholar
Zhu, M. (2004) Biological and geological processes of the Cambrian explosion: evidence from the Yangtze Platform of South China introduction. Progress in Natural Science, 14, VX.Google Scholar