Variation in clastic input in the Berriasian of the Lower Sub-Tatric (Krížna) succession in the Tatra Mountains (Central Western Carpathians, Poland): data from magnetic susceptibility and inorganic geochemistry

Abstract

Ab stract: The pa per deals with the age and palaeoenvironment in ter pre ta tion of the Late Berriasian sed i men tary tran si tion from micritic calpionellid lime stones to marls, cor re spond ing to the pas sage from the Osnica For ma tion to the Koœcieliska Marl For ma tion, Lower Sub-Tatric suc ces sion, Tatra Mts., Cen tral West ern Carpathians. Since only re li ably dated sec tions are an ap pro pri ate ba sis for palaeoenvironmental study, the fol low ing pe lagic and hemipelagic sec tions were cho sen ow ing to en rich ment in fine, clastic ma te rial and the ex ist ing biostratigraphic and magnetostratigraphic frame works: Poœrednie III, Rowienka, G³adkie Up³azianskie and Gesia Szyja. The au thors in te grated and in ter preted new, de tailed data on mag netic sus cep ti bil ity (MS), rock mag ne tism and el e ment geo chem is try from all of the sec tions. Well de fined biostratigraphy per mit ted the test ing of the po ten tial of MS as a strati graphic method. Ow ing to its close con nec tion to se lected terrigenous el e ments (e.g., Al, Th, Zr), MS could be used here as a proxy for de tri tal in put into the ba sin. Its value as a cor re la tion tool in a pe lagic and hemipelagic set ting was con firmed. MS per mit ted not only de tailed cor re la tion of the out crops stud ied, but also the com par i son of them with the Barlya sec tion (West ern Bal kans) of the same age. This study proves that in creased de tri tal in put be gan in the Calpionellopsis sim plex Subzone and con tin ued into the lower part of the Calpionellopsis oblonga Subzone. It might be re garded as syn chro nous event within the Zliechov Ba sin and it is not ev ery where cor re lated with the for ma tion bound aries. The change in sed i men ta tion was not only a lo cal phe nom e non. The on set of de po si tion of the terrigenous frac tion can be iden ti fied in many sec tions of the West ern Tethys. Two in de pend ent fac tors, re gional re gres sion and an in crease in hu mid ity might have con trib uted si mul ta neously to the in creased de tri tal in put in Late Berriasian time. How ever, this pic ture is fur ther com pli cated by tec tonic ac tiv ity on lo cal and re gional scales.