Análisis estratigráfico, procedencia y caracterización de facies correspondientes a los depósitos sedimentarios de la formación san mateo de la cuenca de Manabí: análisis petrográfico, caracterización de facies y geodinámica de la fm. San Mateo.

Abstract

This paper analyzes the petrography and characterization of facies of the different formations of the Manabí basin, which includes the coastal area between Valdivia and Pedernales where the San Mateo Formation emerges and the underlying and overlying formations within this basin. For which, three stages of study are presented: in the first is the analysis of the different lithologies belonging to the Piñón, Cayo, Calentura and San Mateo formations, which were complemented with the description of 12 thin sheets through the elaboration of petrographic sheets for a greater understanding; The second stage consists of the interpretation of sedimentological facies based on what was sampled and collected in the field; finally, an evolutionary model of the formations present within the Manabí basin is exposed. The results allow us to indicate that the basement of the Ecuadorian coast (Fm. Piñón) can be found as rock fragments next to other formations within the Fm. San Mateo, according to our study, this is due to the presence of several tectonic events (double subduction and faulting by the Chongón Colonche Mountain Range, Jubones, among others). In addition, it is proposed that the sedimentary environment of the Fm. San Mateo is an underwater fan due to the lithological deposits (conglomerates and sandstones) and sedimentological and turbiditic facies found in the field.