Fig. 5

Potential microfauna observed in Série Rousse samples. CL: cathodoluminescence; PPL: plane-polarized light. a Thin section from a conglomerate of the very base of the Série Rousse; Pic d’Artsinol [2′599′170/1′108′585]; sampled a few meters from Fig. 8a. The thickness of the conglomeratic level does not exceed 2 m; the mm- to cm-sized clasts are mainly made of dolomites and limestones; a gradual transition is observed to the overlying typical calcschists of the Série Rousse. In comparison with the intense strain generally observed in other samples of the Série Rousse, strain is locally exceptionally low, which allows the preservation of some microfauna that is generally entirely destructed elsewhere. Rounded borders of the clasts could suggest an incomplete diagenesis of the clasts, before their reworking into the conglomerate. b Holothuroidea fragments from the matrix of the conglomerate in the same thin-section. c Holothuroidea fragment from arenitic calcschist of the Série Rousse, sampled few meters above. d Probable reworked echinoderm remains; shapes of the dark rims (CL) suggest stereomes of crinoid ossicles. e Probable planktic foraminifera observed as intraclast in a rounded, dark micritic limestone pebble. The form may correspond to Globotruncana neotricarinata, Petrizzo, Falzoni and Premoli Silva (2011) indicating an age range from Campanian to earliest Maastrichtian for the rounded clast. In order to preserve the observed form, the polishing protocol was not fully completed on this thin section. f, g Potential radiolarian from a dark micritic limestone clast from the base of the Série Rousse; fuzzy borders of the forms could indicate a partial infill of the sediment inside the pores of radiolarian tests; Evolène [2′606′105/1′109′340]