Preservación y significado paleoambiental de macrofauna de un afloramiento tipo del sector Macondamine

Abstract

Abstract: The study of marine sediments provides a solid basis for reconstructing past environmental processes and long-term variability, because these materials preserve stratigraphic and paleontological signals that allow the depositional history and margin dynamics to be interpreted with continuity. Standard geological procedures were applied to describe rock outcrops and build stratigraphic columns, establishing a chronological sequence in which the oldest beds occur at the base and the youngest beds at the top, and the collected samples were analyzed at the Geology laboratory of the Universidad Técnica Particular de Loja, producing information on lithofacies, sedimentary processes, preservation features, and the fossil record that supports a deep marine depositional interpretation for the Casanga Formation. This work was carried out in the Macondamine neighborhood, Casanga parish, Paltas canton, Loja Province, where the Casanga Formation crops out with an estimated thickness of 200 400 m and a stratigraphic relationship that shows a discordant contact with younger units toward the northeast, including the Río Playas Formation. A detailed paleontological assessment focused on the macrofauna of this outcrop had not been conducted in the area prior to this research, so the study aimed to analyze the local fossil record, evaluate its fossil potential, and connect it with the sedimentological and regional basin framework, providing a clearer synthesis of the formation through the integration of field observations, laboratory analyses, and discussion of the scientific sources used in the project.