Stratigraphy and tectonics of the uppermost Bucegi Conglomerate Formation (Albian, Eastern Carpathians, Romania)

Abstract

This paper presents a detailed lithostratigraphic investigation carried out in the Bucegi Massif, a mountainous zone from the southern part of the Eastern Carpathians. The study focused on the 50 - 70 m thick succession of four conglomerate units associated with olistoliths, intercalated in the upper part of the Babele Sandstone Member (the uppermost lithostratigraphic unit of the Albian Bucegi Conglomerate Formation). The conglomerate beds succession stands for the uppermost strata of the thick Bucegi conglomeratic accumulation. All the four conglomerate bodies are stratiform and continuous for almost two kilometers, and show mainly constant lithofacies features on wide areas. The study emphasizes two large-scale trends of high implication on depositional interpretation. The reduced areal extension of the basal conglomerate unit, compared with the larger extension area of the overlying units 2, 3 and 4, is one of the features with genetic significance. Another remarkable characteristic is the lateral passage from the single thick conglomerate units 2, 3 and 4, to conglomerate units alternating with sandstones beds. Another remarkable characteristic is the northwards amalgamation of the conglomerate units 1, 2, 3 and 4 into a single body, named in this paper the Conglomerates with Olistoliths.