(a) Detailed photograph of sample A1 and its related thin-section in natural light. The sample A1 is dominated by breccia and mineralized veins in a micritic to microsparitic matrix rich in shell fragments. (b) The thin-section natural light and polarized illuminations coupled to Raman analyzes display five different calcites: C1, in red, is a micro-sparitic calcite replacing shell fragments; C2, in blue, is a light-brown drusy calcite which is microsparitic when in contact with the micritic matrix and becomes more drusy towards the centre of the vein; C3, in green, is an equant calcite, always in contact with the calcite C2 but never in contact with the micritic matrix; C4, in purple, is a white equant or blocky calcite filling all remaining space in the veins; C5, in black, is a white microsparitic calcite present in veins crosscutting all previous generations. They were isotopically analyzed for C, O and Sr on 12 samples (see text for details and Tab. 1 for values).