Geochemical study of garnet-vesuvianite-wollastonite-pyroxene mineral assemblage in Hosh Skarns, west of Taft (Yazd)

Abstract

The injection of I-type granitoid bodies (Hosh intrusion) with calc-alkaline affinity into Lower Cretaceous limestones (Taft Formation) has produced the various types of related skarns and marbles. Thereby, those skarns formed can be undoubtedly divided into four groups, clinopyroxene-plagioclase skarns, clinopyroxene skarns, clinopyroxene- vesuvianite skarns and moreover garnet skarns. Additionally, calc-silicate bearing marbles also show an especial mineral assemblage consisting of olivine, clinopyrocxene, garnet and vesuvianite. Based upon geochemical studies, two types of garnet can be distinguished in these skarns. The first, Type is the garnets with grossular composition in which they are found with calc-silicate assemblages in skarns and the second, Type is the garnets with andradite composition present in garnet skarns. Clinopyroxenes in those skarns feature a composition varying between Ca-rich diopsides, salite and fassaite. Based on the chemical composition of the intrusive body and the related skarns, one can conclude the close relationship of these skarns with Cu and Zn skarns.

Keywords


[1] Karimzadeh Somarin A., "Marano volcanic rocks, East Azarbaijan Province, Iran and associated Fe mineralization", J. Asian Earth Sci. 24 (2004a) 11-23.

[2] Karimzadeh Somarin A., "Garnet composition as an indicator of Cu mineralization: evidence from skarn deposits of NW Iran", J. Geochemical exploration 81 (2004b) 47-57.

[3] Karimzadeh Somarin A., Moayyed M., "Granite and gabbro-diorite associated skarn deposits of NW of Iran", Ore Geol. Rev., 20 (2002) 127-138.

[4] حاج ملاعلی، ع، "نقشه زمین‌شناسی خضرآباد"، مقیاس 1/100000، سازمان زمین‌شناسی ایران، (1371) شماره 6753.

[5] Irvine I.C., Baragar W.R.A., "A guide to chemical classification of the common volcanic rocks", Can. J. Earth Sci. 8 (1971) 523-548.

[6] Maniar P.D., Peccoli P.M., "Tectonic discrimination of granitoid", Geo. Soc. Am. Bull.101 (1989) 113-125.

[7] Pearce J.A., Harris N.B.W., Tindle A.G., "Trace element discrimination diagrams for the tectonic interpretation of granitic rocks", J.Petrol. 24,4 (1984) 956-983.

[8] Shimazaki H., "Characteristics of skarn deposits and related acid magmatism in Japan", Econ. Geol. 75 (1980) 173-183.

[9] Einaudi M.T., Meinert L.D., Newberry R.J., "Skarn deposits", Econ. Geol. 75th Anniversary Volume, (1981) 317-391.

[10] Meinert L.D., "Variability of skarn deposits, guides to exploration", In: Boardman, S.J. (Ed.), Revolution in the Earth Sciences. Kendall-Hunt Publishing, Dubuque, Iowa, pp. (1983) 301-316.

[11] Meinert L.D., "Skarn deposits in Nevada, Geology, mineralogy and petrology of Au, Cu, W and Zn skarns", In: Meinerts, L.D., Myers, G.L., Brooks, J.W., (Eds.), Geol. Assoc. Can. Spec. Pap. 40, Toronto, (1990) pp. 569-583.

[12] Meinert L.D., "Igneous petrogenesis and skarn deposits", Geol. Assoc. Canada Spec. Pap. 40 (1993) 569-583.

[13] Meinert L.D., "Compositional variation of igneous rocks associated with skarn deposits", In: Kirkham, R.V., Sinclair, W.D., Thorpe, R.I., Duke, J.M., (Eds.), Geol. Assoc. Can. Short Course Series, 23, Nepean, Ontario, (1995) pp. 401-418.

[14] Meinert L.D., "Application of skarn deposit zonation models to mineral exploration", Explor. Min. Geol. 6 (1997) 185-208.

[15] Meinert L.D., "Mineralogy and petrology of iron skarns in Western British Colombia", Canada. Econ. Geol. 79 (1984) 869-882.

[16] Droop G.T.R., "A general equation for estimating Fe+3 concentrations in ferromagnesian silicates and oxides from microprobe analyses using stoichiometric criteria", Mineralogical Magazine 51 (1987) 431-435.

[17] Meinert L.D., "Skarns and skarn deposits", Geosciences Canada 19 (1992) 145-162.

[18] Deer W.A., Howie R.A., Zussman J., "Rock-forming minerals, single chain silicates", 2ed., 2A (1978) Longmans, London.

[19] Kwak T.A.P., "W-Sn skarn deposits and related metamorphic skarns and granitoids", Elsevier, Amsterdam (1987).