Cyclostratigraphy of an upper Valanginian - lower Hauterivian mixed siliciclastic-carbonate ramp succession (Pilmatué Member of the Agrio Formation), Loma La Torre Section, Northern Neuquén Basin, Argentina

KIETZMANN, D.A.; PAULIN, S.

CRETACEOUS RESEARCH (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2019 vol. 98 p. 26 - 46

0195-6671

Detailed sedimentological and stratigraphical studies were performed in the Pilmatué Member of the Agrio Formation at Loma La Torre area, in order to recognize orbital signals in the Valanginian-Hauterivian of the Neuquén Basin. Facies analysis allowed us to recognize 14 lithofacies grouped into 5 facies associations, interpreted as a mixed siliciclastic-carbonate ramp setting. A sequence stratigraphic analysis was performed in order to subtract eustatic trends in time series constructed by lithological rhythms (limestone/marlstone couplets). Considering the three members of the Agrio Formation, two low-frequency depositional sequences are defined. Each one contains a lowstand system tract characterized by shallow marine or continental clastic facies, a transgressive system tract comprising rhythmic alternations of limestones and marlstones, and a highstand system tract composed by clastic marine facies. Cyclostratigraphic analysis shows that the rhythmic Valanginian- early Barremian succession presents a cyclical stratigraphic pattern composed by elementary cycles (limestone/marlstone couplets), bundles (4-5 elementary cycles) and superbundles (4-5 bundles) suggesting a climatic Milankovitch control.