Sequence stratigraphy and facies analysis of the Arro-Broto Turbidite System in the Castisent-Broto depositional sequence of the Hecho Group (Eocene, South-central Pyrenees)

Abstract

El presente artículo se basa en un detallado análisis de las facies del Sistema Turbidítico de Arro-Broto. Los autores distinguen cinco unidades en la Sequencia Deposicional de Castisent-Broto. La unidad superior (E) equivale al lowstand wedge representado por facies limosas de offshore. Las cuatro unidades inferiores (A, B, C y D) tipifican el intervalo temprano del lowstand system tract. La unidad A se corresponde con los fan lobes, mientras que las unidades B y C son comparables con los fan channels. La parte inferiorr de la unidad D representa el slope fan, y la superior, los intervalos iniciales del lowstand wedge. Finalmente la parte inferior de la unidad E correlaciona bien con el lowstand wedge, y la superior con el intervalo basal del transgressive system tract.This article is based on a detailed facies analysis of the Arro-Broto Turbidite System. The authors distinguished five depositional sequence units in the Castisent-Broto. The upper unit (E) is equal to the lowstand wedge, represented by offshore muddy facies. The five lower units (A, B, C and D) classify the early gap of the lowstand system tract. Unit A is related to the fan lobes, whereas Units B and C are comparable to the fan channels. The lower part of Unit D represents the slope fan, and the upper part represents the initial gaps of the lowstand wedge. Finally, the lower part of unit E correlates with the lowstand wedge, and the upper part correlates with the basal gap of the transgressive system tract.