Selon moi le contact entre la detrical Unit et le substratum n'est pas facile a identifier, car double. Il y a une faille dans le jurassique qui a du jouer avant et pendant le depot du Miocene. Donc comme deja ecrit, je pense que la depot arenacé rougeatre est en contact discordant (peu accentué) et represente la partie distale d'un cône de dejection sur cette faille qui a été reprise en surface d'erosion.
Pomar et al (2002) cité ci dessous nous explique que la "Detrical Unit" ne se voit que sur deux affleurement discret (clui de Cala Morell, dont Kayou nous a pris une belle photos) et à Mao (as tu des photos Kayou?).
Suivant les auteurs, les cartographes le contact est mis en faille ou en discoradnace voir les deux, donc tous le monde à raison a mon avis, puisque faille il y a et discordance egalement.
"Upper Miocene rocks (Lower Tortonian to Lower Messinian) of the Migjorn region are subhorizontal and unconformably overlie Palaeozoic, Mesozoic and Palaeogene strata (Obrador, 1972–73). Locally, the Upper Miocene succession overlies two unconformity-bound shallow-marine depositional units: the Basal Unit and the Detrital Unit, which have been tentatively attributed to the Lower and the Middle Miocene respectively (Obrador et al., 1983a, 1992). The Basal Unit consists of limestone and dolostone conglomerate composed of pebbles with bivalve and sponge borings and corals, and calcarenites with smallscale cross-beds. The Basal Unit sediments are interpreted as nearshore and cliff-toe deposits. The Detrital Unit is only known from two discrete outcrops at the boundary between the Tramuntana and Migjorn regions (Cala Morell and Mao´ ; Fig. 2). It is mainly composed of red sandstones and conglomerates that pass upsection and basinward into mixed siliciclastic–carbonate grainstones with marine faunal remains, and is interpreted as a fan-delta deposit (Rosell et al., 1976; Obrador et al., 1983a,b; Obrador & Pomar, 1983)."
Pomar, L., Obrador, A.,Westphal, H., 2002. Sub-wave base cross-bedded grainstones on a distally steepened carbonate ramp, Upper Miocene, Menorca, Spain. Sedimentology 49, 139–169.