Upper Jurassic-Lower Cretaceous limestones from the Hăghimaș Massif (Eastern Carpathians, Romania): Microfacies, microfossils and depositional environments
Les calcaires du Jurassique supérieur-Crétacé inférieur du Massif de Hăghimaș (Carpathes orientales, Roumanie) : Microfaciès, microfossiles et environnements de dépôt

Olimpiu Neamţu
2019 Carnets de Géologie  
U Up pp pe er r J Ju ur ra as ss si ic c--L Lo ow we er r C Cr re et ta ac ce eo ou us s l li im me es st to on ne es s f fr ro om m t th he e H Hă ăg gh hi im ma aș ș M Ma as ss si if f ( (E Ea as st te er rn n C Ca ar rp pa at th hi ia an ns s, , R Ro om ma an ni ia a) ): : M Mi ic cr ro of fa ac ci ie es s, , m mi ic cr ro of fo os ss si il ls s a an nd d d de ep po os si it ti io on na al l e en nv vi ir ro on nm me en nt ts s Abstract: The Hăgimaş Massif provides important data for
more » ... nt data for reconstructing the geological evolution of the Transylvanian Carbonate Platform. This unit is present nowadays in the basement of the Transylvanian Depression and as large-scale olistoliths, which crop out in various locations in the Eastern Carpathians and Apuseni Mountains. They contain a large variety of microfacies as well as microfossil assemblages partly encompassing the Jurassic/Cretaceous boundary. This study presents a detailed account of uppermost Jurassic-lowermost Cretaceous limestones from the Lapoş Valley (Hăghimaş Mountains) containing two distinct successions separated by a fault. The first succession contains platform margin and inner platform deposits (subtidal, intertidal) whereas the second one consists of inner platform deposits (shallow-subtidal to peritidal carbonates). The Upper Jurassic Stramberk-type facies is overlain by lower Berriasian regressive peritidal limestones. The upper Berriasian-? lower Valanginian consists mainly of inner platform deposits. They contain alternating, high and low-energy carbonates with rare calpionellids and calcispheres. The age assignment is based on a rich and diverse micropaleontological assemblage containing similar biota reported from other regions of the Tethysian Realm.
doi:10.4267/2042/70499 fatcat:nd2pwhxhcbfdfeprn3trw7xcya