3.1.1. Sample OM10

Calcite is the dominant mineral component of the sample. Dolomite is present in minor amounts. The fabric is strongly heteroblastic, ("mortar-type", Figure 11a). Tectonic deformation is

expressed by the presence of mm-sized bands, which are macroscopically observed as grey-colored stripes. They are composed of fine-grained calcite, along with parallel-oriented, mica-group minerals (phlogopite/muscovite). MGS values reach up to 2.0 mm for the coarse grain parts and are significantly lower, up to 0.4 mm, in the fine-grained bands. Xenomorphic crystals of calcite in the groundmass often exhibit polysynthetic twinning, as a result of deformation. Grain boundary shapes are typically sutured, in some cases embayments were also identified (Figure 11b). Accessory minerals are commonly phlogopite, rarely apatite and pyrite (Figure 11c,d).
