Litoestratigrafía del sondeo de Calzada de Don Diego (Fosa de Ciudad Rodrigo)

Resumen

This work highlights the new geological data from subsurface in the Ciudad Rodrigo basin which reveals important stratigraphic constrains. The Borehole of Calzada de Don Rodrigo is 122 m deep and reaches the basement of the basin constituted by schists and slates from the Precambrian-Cambrian Monterrubio Formation. On this basement there is non-conformity surface succeeded by the first terrigenous succession 62 m thick, mainly composed by polimictic pebbles and cobbles at the base (firts 12 m) and 50 of mudstones and fine-grained sandstones at the top. The upper 57 m previous fine succession. This disconformity is marked by a thick (3m) calcrete bed followed by a red siliciclastic breccia. The lowest succession is interpreted as distal alluvial and lacustrine deposits and is correlated with the Entrala Formation (Rhenanian-Headonian; Eoceno). The Upper succession is interpreted as a braided fluvial system with paleocurrents towards the northeast and belongs to the El Cubito Foramtion (Aragonian; Mioceno).