Lateral Continuity and Thinning Ratios, an Analysis of Thin Beds Within a Storm Dominated Prodelta: Cretaceous Ferron Sandstone, Utah

Heterolithic strata are deposited in a variety of delta front to offshore marine environments. There are many physical bedding processes that cause the deposition of various sedimentary successions within these environments, including hypopycnites, hyperpycnites, ignitive turbidites, and tempestites. The purpose of this study is to analyze a three-dimensional outcrop exposure to investigate lateral continuity and thickness of thin beds as they relate to physical bedding processes. Data for this study was obtained from five measured sections taken at centimeter scale resolution, as well as a three dimensional photorealistic drone model of parasequence 5b of the Ferron Sandstone member. Parasequence 5b is an aggrading, storm dominated fluvially influenced parasequence, which transitions from prodelta to delta front facies. The correlation and measurements of bed thickness spanned 155 meters of outcrop surface. Thickness measurements were made for five laterally continuous sandy beds every 0.5 meters. The continuous beds were used as constraints for the correlation of all other beds that lie in between. At least 10% of beds are laterally discontinuous over the 155 meters of analyzed outcrop. Thickness measurements allowed for lateral continuity estimates of hummocky cross stratified beds, and estimate lateral continuity for up to 1600 meters. Lateral discontinuity is shown to actively be caused by amalgamation of hummocky cross stratified tempestite deposits. This is pertinent to oil and gas research as a fundamental understanding of lateral continuity as it relates to physical bedding process can aid in reservoir predictions and risk assessment.