Space, Things, Time, and Events: Horacio Harrington, Derek Ager, and the Dichotomous Future of Sequence Stratigraphy

Abstract

The conceptual framework and practical application of sequence stratigraphic principles followed two distinct yet overlapping paths nearly from the onset of sequence stratigraphic studies. The varied applications of sequence concepts to seismic stratigraphic data and to chronostratigraphic data fostered the development of multiple working methods and uses of terminology that all fall under the umbrella of sequence stratigraphy. The most obvious example of multiple working methodologies being separated by a common language is the use and stratigraphic placement of the ‘sequence boundary’. Throughout the decades, ‘sequence stratigraphers’ have chosen nearly every position within the systems tracts framework to define the sequence boundary (e.g. top of the HST, top of the FSST, base of the TST, etc.). A variety of causes can be attributed to the disparate use of sequence stratigraphic terminology over the years, but 21st Century sequence stratigraphers fall largely into one of two camps. Seismic stratigraphers, who utilize increasingly high-resolution 3-D seismic stratigraphic data, or chronostratigraphers, who utilize increasingly high-resolution chronostratigraphic data. The two groups, who both practice sequence stratigraphy, not only rely on fundamentally different sets of data, they also have fundamentally different objectives. Seismic stratigraphy endeavors to determine the spatial distribution of strata (and their attendant oil and gas); chronostratigraphy aims to determine the sequence of events in Earth history and ultimately the causes and consequences of those events. These separate, but related, aims and primary sets of data are largely responsible for the varied use of sequence stratigraphic terms and principles. The revolution of high-resolution 3-D seismic stratigraphy is well documented and is the driving force behind 21st Century seismic sequence stratigraphy. This presentation aims to demonstrate that a similar revolution in high-resolution global chronostratigraphy is also taking place and has similarly revolutionized outcrop- and core-based sequence stratigraphy over the past two decades as well. The future of both sequence stratigraphic enterprises (high-resolution seismic stratigraphy and high-resolution chronostratigraphy) rests in our ability as a community of sequence stratigraphers to overcome the barriers presented by our common language and effectively integrate both stratigraphic revolutions.

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