¹⁸O/¹⁶O and V/Cr ratios in gem tsavorites from the Neoproterozoic Mozambique metamorphic belt: a clue towards their origins?

Giuliani, G., Fallick, A.E., Feneyrol, J., Ohnenstetter, D., Pardieu, V. and Saul, M. (2011) ¹⁸O/¹⁶O and V/Cr ratios in gem tsavorites from the Neoproterozoic Mozambique metamorphic belt: a clue towards their origins? Mineralium Deposita, 46(7), pp. 671-676. (doi: 10.1007/s00126-011-0355-6)

Abstract

The combination of oxygen isotope composition with V–Cr–Mn trace element concentrations of V-bearing garnets (tsavorites) originating from the main deposits of the Neoproterozoic Mozambique Metamorphic Belt is reported for the first time. The database enables the identification of the geological and geographical sources of the main productive areas from northern and southern Tanzania, Kenya, and Madagascar. Three consistent sets of δ¹⁸O values between 9.5‰ and 11.0‰, 11.6‰ and 14.5‰, and 15.5‰ and 21.1‰ have been recognized for primary deposits hosted in graphitic gneisses related to the Neoproterozic metasedimentary series. The δ¹⁸O value of tsavorite is a good tracer of the environment of its formation; the δ¹⁸O of the fluid in equilibrium with tsavorite was buffered by the host rock during metamorphism and fluid-rock interaction. This study is a first step in characterizing the geochemistry of gem tsavorite from most of the deposits and occurrences worldwide.

• Item Type: Articles (Letter)
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fallick, Professor Anthony
• Authors: Giuliani, G., Fallick, A.E., Feneyrol, J., Ohnenstetter, D., Pardieu, V., and Saul, M.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Mineralium Deposita
• Publisher: Springer
• ISSN: 0026-4598
• ISSN (Online): 1432-1866
• Published Online: 15 May 2011