Climate, Fluvial Sytle Evolution, and Their Relationship with Reservior Quality and Continuity of the Late Triassic Chinle Formation, Petrified Forest National Park, Arizona
Russell Hunter Harlow
Geology, Baylor University, China Spring, TX, USA
The Late Triassic Chinle Formation in Petrified Forest National Park, Arizona, provides an excellent opportunity for investigating terrestrial paleoclimate, fluvial stratigraphy, and their associated reservoir properties. This study will examine intervals within Sonsela Member of the Chinle Formation that accumulated under distinctive climatic regimes (humid versus dry) and reconstruct their variable fluvial style and its' relationship to reservoir properties (quality and continuity). Additionally, the findings will be compared with previously documented regional trends to constrain casual influences of deposition. To investigate these relationships, the following approach be taken. First, sedimentology and stratigraphy, including detailed paleosol documentation, will be characterized in a series of 1-D measured sections at regular intervals. These will be overlain onto outcrop photopanoramas onto which the lateral variation in facies, architecture elements, and paleosol pedotypes will be laterally traced. Concomitantly, samples from paleosols will be collected and analyzed for bulk geochemistry, stable isotopic, clay mineralogical, and micromorphologic variability. In addition, samples collected from channel sands will be characterized by textural and compositional maturity, porosity and gross intergranular volume. Collectively, these analyses will allow for reconstruction of climatic conditions and the associated sedimentologic and stratigraphic attributes that influence reservoir quality. This production scale investigation will provide insight into the relationship between climate and fluvial style, and as such, serve as an outcrop analog to similar subsurface reservoirs. Furthermore, results from the study will be compared to previously documented reconstructions of equivalent Chinle strata to evaluate the casual mechanisms (tectonics, climate, eustacy) that may have accounted for regional variability.
AAPG Search and Discovery Article #90199 © 2014 AAPG Foundation 2014 Grants-in-Aid Projects