Fig. 2

Dolostones of the Roisan zone. 1 The Roisan zone (R), with dolostones, marbles and calcschists, is interposed between the Mont Mary-Cervino nappe (MM) and the Dent Blanche nappe (DB) as is clearly visible in the Col de Saleron area. 2 Thick-bedded dolostones nearby the road to Tsa de Chavalary (below Cunéy Sanctuary). This succession shows repeated cycles with thick massive banks separated by thin laminated levels that are very similar to the well-known lagoon-tidal flat cycles. 3 Detail of a laminated level situated between thick massive banks nearby the road to Tsa de Chavalary. 4 Massive bank with green algae (Dasicladales) on the eastern side of Grand Pays, above Alpe Léché. 5 Laminas very similar to planar stromatolites on the eastern side of the Grand Pays above Alpe Léché. 6 Dolostone with planar stromatolites on the top of the Grand Pays