Depositional environments and associated facies of the Late Jurassic Bossier Formation, Freestone County, East Texas Basin.

摘要

Interpretations of the depositional environment of the Late Jurassic Bossier Formation range from deep sea fan to deltaic to fluvial. The purpose of this study is to use the integration of the tectonic history of the basin, recent palynology and kerogen data, core descriptions, and the stacking patterns from well logs within Freestone County, East Texas Basin to evaluate the proposed models. The key observations are: (1) depositional rates kept up with subsidence, (2) a high terrigenous index is from the palynology, (3) Ophiomorpha burrows are in the cores, (4) well logs show a coarsening upward parasequence stacking pattern, (5) and the Bossier Formation is bound by shallow water carbonates at the base, and a fluvial formation at the top. All of the evidence based on the results of this study suggests that the Bossier Formation has characteristics of a shallow marine setting. Specifically, this work interprets the Bossier Formation as a fluvial dominated deltaic system subdivided into four stratigraphic layers. (Abstract shortened by UMI.)