Ancient Processes in Modern Data: Quantitative Seismic Geomorphology for Evaluating the Sedimentary Processes That Characterize the Ancient Earth

Abstract

Sequence stratigraphy is a methodology that is based in the concepts that systems tracts represent distinct “process periods” when the nature of depositional systems, architectural elements and facies distributions are predictable. The surfaces which bound systems tracts and sequences provided the perfect guiding surfaces for rapidly evolving seismic attribute technologies to image these periods in basin history and produce seismic-based images of the geomorphology, essentially a paleo-digital elevation and geomorphologic model of these phases in basin development. The community in the 1980's began to scientifically scrutinize the details of proposed processes and drivers for systems tract development. This interest has continued and led to new ideas in process stratigraphy and sedimentology as well as in advances in physical and numerical modeling. This talk focuses on earth's paleo-geomorphology and approaches to combining conventional geomorphic knowledge in subaerial and submarine systems with seismic geomorphologic images to assess the processes occurring in the geologic past, and create a historical record of process change. In this talk we examine pre-modern fluvial channels as indicators of paleo-topography and river discharge character, ancient seismically-imaged submarine channel, levee and lobe character as indicators of off-the-shelf sediment flow character and behavior as well as seafloor topography, shelf sand morphology and what it indicates about shelf processes and currents, deep ocean sediment waves and what they can tell us about initiation and flow properties of deep ocean currents, and paleo-mass failures. The publication of dual volumes; AAPG Memoir 26 focused on seismic based observations, and SEPM Special Publication 42 focused on observations as well as processes responsible for predicting sedimentology, was a very powerful combination of science that stimulated new conversations and new ideas on the drivers and processes of strata formation and conveyed methodologies for people to make their own observations in their own basins. The power of sequence stratigraphy lies not in its absolute truth, but in its power to peak the imagination of scientists and drive investigation of the paradigms upon which it is founded, resulting in new improved approaches to building and using stratigraphic frameworks. These publications empowered new ideas – one of which became seismic geomorphology.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017