Exposing the inside of the fine-grained siliciclastic tidal shelf deposits of the Alicia Formation, Tandilia Basin, during the Ediacaran anoxia in the Clymene Ocean

MARÍA JULIA ARROUY; LUCÍA GÓMEZ PERAL

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2021 vol. 106 p. 1 - 21

0895-9811

In this contribution we outline the outstanding attributes and inferred depositional controls for dark mudstones of the Alicia Formation (~ 570 Ma) in order to reveal the intrinsic characteristics of unknown Ediacaran marine depositional conditions of the basin. The Alicia Formation represents a continuous and undeformed ~150m thick sequence in which nine siliciclastic lithofacies were accumulated controlled by the Clymene sea conditions. Sedimentary facies analysis of their fine-grained rocks reveals a deposition across two depositional sequences. The basal portion is described as formed in an upper offshore while the upper portion represents a lower shoreface environment. This study combines the stratigraphic characterization with detailed facies descriptions, petrographic, XRD, SEM and geochemistry analyses.