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Conditions for emerald formation at Davdar, China: fluid inclusion, trace element and stable isotope studies

Published online by Cambridge University Press:  05 July 2018

D. Marshall ,
V. Pardieu ,
L. Loughrey ,
P. Jones  and
G. Xue
D. Marshall*
Affiliation:
Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
V. Pardieu
Affiliation:
GIA Laboratory, 10th Floor, 968 Rama IV Rd., Silom Bangrak, Bangkok 10500, Thailand
L. Loughrey
Affiliation:
Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
P. Jones
Affiliation:
Earth Sciences, Carleton University, Ottawa, Ontario K1S 5B6, Canada
G. Xue
Affiliation:
Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
*
*E-mail: marshall@sfu.ca
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Abstract

Preliminary geological work on samples from Davdar in China indicate that emerald occurs in quartz veins hosted within upper greenschist grade Permian metasedimentary rocks including quartzite, marble, phyllite and schist. Fluid inclusion studies indicate highly saline fluids ranging from approximately 34 to 41 wt.% NaCl equivalent, with minimal amounts of CO2 estimated at a mole fraction of 0.003. Fluid inclusion, stable isotope and petrographic studies indicate the Davdar emeralds crystallized from highly saline brines in greenschist facies conditions at a temperature of ∼350°C and a pressure of up to 160 MPa. The highly saline fluid inclusions in the emeralds, the trace-element chemistry and stable isotope signatures indicate that the Davdar emeralds have some similarities to the Khaltaro and Swat Valley emerald deposits in Pakistan, but they show the greatest similarity to neighbouring deposits at Panjshir in Afghanistan.

Keywords

berylChinaDavdaremeraldfluid inclusion studiesgreenschist faciesstable isotope geochemistry
Type
Research Article
Information
Mineralogical Magazine , Volume 76 , Issue 1 , February 2012 , pp. 213 - 226
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2012

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References

An, Y.X. (2009) Geological features of Tashqorghan emerald deposit, Xinjiang, China. Journal of Xinjiang nonferrous metals, 29, 9–10. [in Chinese].Google Scholar
Arif, M., Fallick, A.E. and Moon, C.J. (1996) The genesis of emeralds and their host rocks from Swat, northwestern Pakistan: a stable isotope investigation. Mineralium Deposita, 31, 255–268.CrossRefGoogle Scholar
Bakker, R.J. (2003) Package FLUIDS 1. Computer programs for analysis of fluid inclusion data and for modelling bulk fluid properties. Chemical Geology, 194, 3–23.CrossRefGoogle Scholar
Blauwet, D., Quinn, E. and Muhlmeister, S. (2005) New emerald deposit in Xinjiang, China. Gems & Gemology, 41, 56–57.Google Scholar
Bodnar, R.J. (2003a) Introduction to fluid inclusions. Pp. 1–8. in: Fluid Inclusions: Analysis and Interpretation (Samson, I., Anderson, A. and Marshall, D., editors). Mineralogical Association of Canada Short Course Series, 32. Mineralogical Association of Canada, Quebec, Canada.Google Scholar
Bodnar, R.J. (2003b) Introduction to aqueous-electrolyte fluid inclusions. Pp. 81–100. in: Fluid Inclusions: Analysis and Interpretation (Samson, I, Anderson, A. and Marshall, D., editors). Mineralogical Association of Canada Short Course Series, 32. Mineralogical Association of Canada, Quebec, Canada.Google Scholar
Brown, P.E. (1989) FLINCOR-A microcomputer program for the reduction and investigation of fluidinclusion data. American Mineralogist, 74, 1390–1393.Google Scholar
Cheilletz, A., Féraud, G., Giuliani, G. and Rodriguez, C.T. (1994) Time-pressure and temperature constraints on the formation of Colombian emeralds; an 40Ar/39Ar laser microprobe and fluid inclusion study. Economic Geology, 89, 361–380.CrossRefGoogle Scholar
Diamond, L.W. (2001) Review of the systematics of CiO2-H2O fluid inclusions. Lithos, 55, 69–99.CrossRefGoogle Scholar
Diamond, L.W. (2003) Introduction to gas-bearing, aqueous fluid inclusions. Pp. 101–158. in: Fluid Inclusions: Analysis and Interpretation (Samson, I., Anderson, A. and Marshall, D., editors). Mineralogical Association of Canada Short Course Series, 32. Mineralogical Association of Canada, Quebec, Canada.Google Scholar
Giuliani, G., France-Lanord, C., Zimmerman, J.L., Cheilletz, A., Arboleda, C., Charoy, B., Coget, P. Fontan, F. and Giard, D. (1997) Fluid composition, dD of channel H2O and d18O of lattice oxygen in beryls: genetic implications for Brazilian, Colombian, and Afghanistani emerald deposits. International Geology Review, 39, 400–424.CrossRefGoogle Scholar
Goldstein, R.H. and Reynolds, T.J. (1994) Systematics of fluid inclusions in diagenetic minerals. SEPM Short Course 31. Society for Sedimentary Geology, Tulsa, Oklahoma, USA, 199 pp.CrossRefGoogle Scholar
Groat, L.A., Giuliani, G., Marshall, D.D. and Turner, D. (2008) Emerald deposits and occurrences: a review. Ore Geology Reviews, 34, 87–112.CrossRefGoogle Scholar
Grundmann, G. and Morteani, G. (1989) Emerald mineralization during regional metamorphism-the Habachtal (Austria) and Leydsdorp (Transvaal, South-Africa) deposits. Economic Geology, 84, 1835–1849.CrossRefGoogle Scholar
Knight, C.L. and Bodnar, R.J. (1989) Synthetic fluid inclusions: I Critical X. PVTX properties of NaCl-H2O solutions. Geo chimicaet Cosmochimica Acta, 53, 3–8.CrossRefGoogle Scholar
Laurs, B.M, Dilles, J.H. and Snee, L.W. (1996) Emerald mineralization and metasomatism of amphibolite, Khaltaro granitic pegmatite-hydrothermal vein system, Haramosh Mountains, Northern Pakistan. The Canadian Mineralogist, 34, 1253–1286.Google Scholar
Marshall, D.D., Diamond, L.W. and Skippen, G.B. (1993) Silver transport and deposition at Cobalt, Ontario, Canada: fluid inclusion evidence. Economic Geology, 88, 837–854.CrossRefGoogle Scholar
Roedder, E. (1984) Fluid Inclusions. Reviews in Mineralogy, 12. Mineralogical Society of America, Washington DC, 644 pp.CrossRefGoogle Scholar
Sheppard, S.M.F. (1986) Characterisation and isotopic variations in natural waters. Pp. 165–183. in: Stable Isotopes in High Temperature Geological Processes (Valley, J.W., Taylor, H.P. Jr and O J.R.’Neil, editors). Reviews in Mineralogy, 16. Mineralogical Society of America, Washington DC, 570 pp.Google Scholar
Schwarz, D. and Giuliani, G. (2001) Emerald deposits-a review. The Australian Gemmologist, 21, 17–23.Google Scholar
Taylor, R.P., Fallick, A.E. and Breaks, F.W. (1992) Volatile evolution in Archean rare-element granitic pegmatites: evidence from the hydrogen-isotopic composition of channel H2O in beryl. The Canadian Mineralogist, 30, 877–893.Google Scholar
Vapnik, Ye. and Moroz, I. (2001) Fluid inclusions in Panjshir emerald (Afghanistan). Proceedings of the XVI European current research on fluid inclusions (ECROFI), 451–454.Google Scholar
Vapnik, Ye. and Moroz, I. (2002) Fluid inclusions from the Jos complex (Central Nigeria). Schweizer Mineralogische und Petrographische Mitteilungen, 80, 117–129.Google Scholar
Xue, G. Marshall, D., Zhang, S., Ullrich, T., Bishop, T. Groat, L., Thorkelson, D., Giuliani, G. and Fallick, A. (2010) Conditions for Early Cretaceous emerald formation at Dyakou, China: fluid inclusion, Ar-Ar, and stable isotope studies. Economic Geology, 105, 375–394.CrossRefGoogle Scholar