Microfacies analysis and endogenic decay causes of carbonate building stones at the Asklepieion Epidaurus monuments of Peloponnessos,Greece

The carbonate building stones from the Asklepeion, Epidaurus, used to construct the monuments of Gymnasium, Tholos and Avaton can be grouped into 12 microfacies types, according to their microfacies characteristics such as the type of groundmass, the different kinds of particles, the facies-diagnostic fossils, the depositional and solution textures. Two of them, oocalcarenite (MF type I) and biocalcarenite (MF type II) belong to the marine Plio-Pleistocene carbonate sediments from Korinthos (ancient quarries in Kechries) and the northern part of the island of Aegina, respectively. Most of them, calcrete (MF type III), red biomicrites (MF type IV and V), oolitic grainstone (MF type VI), bio-grainstone (MF type VII), boundstone (MF type VIII), intrabreccia limestone (MF type IX), cherty biomicrite (MF type X) belong to the sedimentary carbonate formations of Mesozoic age of the adjacent areas in Argolis peninsula. The black lime-biomicrite (MF type XI) comes from a more distant sedimentary lithological formation, most probably from Dervenakia area (Tripolis zone). Finally, one belongs to the metamorphic carbonates (marbles of Naxos?). The endogenic decay causes are controlled by both sedimentary and diagenetic processes reflected in the microfacies type. So, the main endogenic factors of the oocalcarenite and biocalcarenite facies, which were used for the upper architectural members, are high porosity and the quantitative–qualitative mineralogical composition of the insoluble residue, which is mainly composed of swelling clay minerals (smectites). The calcrete facies, which was used in the foundations of all monuments, shows the heaviest decay problems which are related to the high structural irregularities, the high porosity and the quantitative–qualitative mineralogical composition of the non-carbonate minerals. The other facies appear with a weaker degree of decay whose endogenic causes are also investigated.