Figure 7: A) Dissolution zoning of calcite cement on a polished, then slightly etched surface, SEM (Brazilian material). B-F) Pinda Group. B) Slightly dolomitic oolitic grainstone. Here a large dolomite crystal in red color (at the top) is located in an intergranular cement position. The large calcite crystal (in the center) is zoned with a first thick zone dark brown in color, then light brown and orange luminescent zones. This single crystal probably grew on an echinoderm bioclast. This calcite cementation preceded dolomite cementation. C-D) Slightly dolomitized oolitic grainstone with an echinoid spine (e) and its calcite rim cement (c). It is not clear whether all dolomite is replacement only, or replacement and cement (d): C) TL transmitted light; D) CL cathodoluminescence. E-F) cathodoluminescent views of slightly dolomitic oolitic grainstones: E) one zoned calcite crystal is corroded by red dolomite (arrow); F) the large zoned calcite crystal that probably grew on an echinoderm bioclast is partly replaced by dolomite as evidenced here by two rhombic shapes (arrows). For confidentiality purposes the sample depths and the name of wells are not provided.