Beds created by (mostly) sediment gravity flows

Abstract

Every few decades, it helps to summarize the achievements of deep-water studies and integrate new observations into the scientific community, in an effort to more fully understand the state of the science – and the science and classification of deep-water sedimentation units is no exception. The Bouma (1962) Sequence created an era of worship for the classic deposit derived from a low-density turbidity current. Twenty years later, high-density turbidity currents were interpreted to deposit a bed dominated by gravels and coarse sand (Lowe, 1982). Next, scientists recognized slurry, hybrid and transitional flows could deposit mixed muddy sand beds. About that same time, the wave-modified turbidite model was introduced by Myrow et al. (2002). Since then, the proliferation of sedimentation unit models representing deposition via sediment gravity flow has caused researchers to question: which models offer the most utility to understanding sedimentary environments? And importantly: are there sedimentation unit models yet to be found in natural settings? This presentation characterizes sedimentation unit models derived from turbidity currents, transitional flows and debris flows from ∼1950 to Present, with special attention to sediment gravity flow deposits that are modified, reworked or initiate d by wave, tide, fluvial and bottom current (i.e., contour current) processes. While no one model is considered the global hegemon in 2022, there are a variety of models that best fit certain environmental conditions in deep oceans and lakes. Each model carries its own merits, limitations and pitfalls for oil and gas exploration and development. Note: This paper was accepted into the Technical Program but was not presented at IMAGE 2022 in Houston, Texas.