Evolución de los sistemas lacustres asociados al estadio temprano de rift en el Semigraben de Rupelo (NO de la Cuenca de Cameros, España)subsidencia e influencia marina.

Zusammenfassung

In the Rupelo Halfgraben the three depositional sequences (DS1, DS2, DS3) which correspond to the beginning of the Mesozoic Iberian Rift in the NW area of Cameros Basin have been distinguished, each of them consisting of a carbonate lacustrine system which retrogrades over an alluvial system. The three lacustrine systems show differences related to changes during the halfgraben evolution at the beginning of the rift. The lacustrine system from DS1 (Boleras Fm) consists of lacustrine desiccation sequences deeply pedogenetically modified and paleosoils in the palustrine edge, which indicates that subsidence during its deposition was intermittent. Tha lacustrine system from DS2 (Campolara Fm) consists of thicker lacustrine desiccation sequences, with less pedogenic modifications, laminar paleosoils in the lacustrine edge and aggrading geometry at its top, which indicates that subsidence was still intermittent but with more stable intervals. The lacustrine system from DS3 (Río de San Marcos Fm) was a mixed carbonate-siliciclastic system and shows evidence of marine influence. The presence of an open lacustrine environment without pedogenic modifications and the poor development of the coastal and the palustrine edge environments indicate that subsidence generation was continuous.