Sedimentary succesion of the Lower Cretaceous deposits from the north-western part of Pădurea Craiului (Apuseni Mountains, Romania)

Authors

Daniel F. Lazar, Department of Geology, Babes-Bolyai University, Cluj-Napoca, RomaniaFollow
Ioan I. Bucur, Department of Geology, Babes-Bolyai University, Cluj-Napoca, RomaniaFollow
Ioan Cociuba, Geological Institute of Romania, Cluj branch, RomaniaFollow
Emanoil Sasaran, Department of Geology, Babes-Bolyai University, Cluj-Napoca, RomaniaFollow

Abstract

Within the general succession of the Lower Cretaceous deposits from the Vârciorog-Dobreşti area (Pădurea Craiului Mountains), carbonate and terrigenous deposits were identified. The limestones were assigned to two distinctive lithostratigraphic units: the Valea Măgurii and Vârciorog formations. Based on the orbitolinids Palorbitolina lenticularis and Mesorbitolina texana their ages are assigned to the early Aptian, and respectively late Aptian–Albian. The terrigenous facies mainly include fine grained deposits (clays, siltites, marls) and, to a lesser extent, coarser ones (glauconitic sandstones and conglomerates), and they are attributed to the Ecleja and Vârciorog formations. The marls of the Ecleja Formation have been observed in a single section. The lack of fossils prevents assigning an age to this marl succession. Based on their relative location, i.e., at the base of the late Bedoulian Valea Măgurii Limestones, they may be assigned to the early Aptian (early Bedoulian). The siliciclastic deposits of Vârciorog Formation cover the largest areas in the region. Their late Aptian–Albian age is established based on the presence of Mesorbitolina texana. Additional arguments are represented by an ammonite fauna assigned to the terminal Bedoulian–early Gargasian. This fauna is located at the base of the Vârciorog Formation. The Lower Cretaceous deposits cropping out in this area have been investigated in seven geological sections. The data interpretation allowed a synthetic reconstruction of the succession and of the depositional environments.

Recommended Citation

Lazar, Daniel F.; Bucur, Ioan I.; Cociuba, Ioan; and Sasaran, Emanoil (2012) Sedimentary succesion of the Lower Cretaceous deposits from the north-western part of Pădurea Craiului (Apuseni Mountains, Romania), Studia UBB Geologia 57 (1): 33-51
DOI: http://dx.doi.org/10.5038/1937-8602.57.1.4
Available at: https://digitalcommons.usf.edu/geologia/vol57/iss1/art4