Facies analysis of the Late Cretaceous deposits from Corni Quarry (north-eastern border of Gilău Mountains)

The Late Cretaceous deposits outcropping along the northeastern border of Gilău Mountains form a NW-SE-oriented crest. The crest is delimited westwards by the crystalline formations of Baia de Arieş Nappe. Within these deposits, two distinctive sedimentary complexes could be separated: a) The Gosau-type facies formation, that can be correlated to the “Lower Gosau Subgroup” (Wagreich & Faupl, 1994), represented by alluvial/fluvial fans and shallow marine deposits; b) The flysch-type formation, that is similar with the “Upper Gosau Subgroup” (Wagreich & Faupl, 1994) and includes deep sea deposits (hemipelagites/turbidites).The syndepositional and postdepositional tectonics controlled the sedimentation and facies distribution; the shallow carbonate deposits are embedded in distal shelf marine ones. Isolated blocks of various sizes represent the rudist-bearing limestones (from m2 up to hundreds of m2). The present study focuses on the identification of facies and depositional environments of the limestones outcropping along Pleşcuţa valley, in Corni Quarry (SW from Finişel village). Based on sedimentological features and faunal associations, the following facies associations have been identified: 1) Marls and limestone with terrigenous clasts; 2) Build-ups with tubular/massive corals and rudists; 3) pillarstone-type bioaccumulations with branching/platy corals; 4) bioclastic rudstone/grainstone; 5) bioclastic floatstone/ packstone. All these facies associations indicate a coastal environment developed along a shelf margin influenced by both the terrigenous supply, and the relative sea level variations