δ44Ca of stratabound fluorite deposits in Burgundy (France): tracing fluid origin and/or fractionation processes

Combined Sr and Ca isotopic tracers have been applied to stratabound fluorite deposits in the central part of Burgundy (France). These deposits are spatially related to an unconformity between a Palaeozoic granitic and metamorphic basement and Late Triassic sediments. The aim of this work is to trace the origin of fluid(s) from which stratabound fluorite deposits formed. We suggest that the variations of the delta Ca-44(SW) in fluorite (-0.1 to +0.2 parts per thousand relative to seawater sw) could be explained by 1) precipitation from a fluid dominated by a Ca isotopic signature similar to that of seawater (calcite or dolomite dissolution from the host-rock) and a Sr isotopic ratio higher than seawater (granitic basement) and involves no fractionation, the preferred scenario or 2) cristallization from a fluid with a low delta Ca-44(SW) (carbonate and silicate sources) involving fractionation processes. (C) 2015 The Authors. Published by Elsevier B.V.