University of Texas at Austin

Applied Geodynamics Laboratory

April 6, 2018

The Applied Geodynamics Laboratory (AGL) is dedicated to producing innovative new concepts in salt tectonics. AGL attempts to understand salt tectonics using three complementary approaches. These three wings of the AGL project work together to build our understanding of salt deformation.

The first approach used by AGL involves kinematic and stratigraphic analysis of salt structures in some of the world’s most spectacular salt basins. The goals of these studies are (a) to understand the geometries of salt structures, the settings in which they form, and through structural restoration their histories, and (b) to investigate the ways in which larger plate-tectonic processes affect the evolution of salt basins. A recent study utilizing 3D seismic data from the Precaspian Basin studied the effects of mild orogenic shortening on minibasin subsidence and displacement. Another study in the northeastern Gulf of Mexico analyzes the effects of basin opening on salt styles.

GOM studies

Evolution of salt structures during Jurassic opening of the Gulf of Mexico basin. From Hudec et al., 2013.

AGL’s second approach utilizes physical models to study the processes by which salt structures form, and how these structures are affected by changing conditions. Physical models allow us to vary salt thickness, strain rates, basement configuration, and a host of other parameters systematically, in order to assess their impact on the evolution of salt structures. In many cases, structural styles observed on seismic data in our regional studies are simulated in physical models.

Physical model

Physical model of a bucket minibasin sinking into a salt feeder. Courtesy of Tim Dooley.

The third approach used by AGL to investigate salt-tectonic processes uses finite-element models. In these models, we can study the influence that salt movement has on stresses and fluid pressures in surrounding sediments. Furthermore, we can analyze the feedback effect that perturbed stresses and fluid pressures have on the subsequent evolution of the salt structures. Our research to date has focused on the growth of salt walls and salt stocks, and on the emplacement of salt sheets. On long-term goal is to be able to simulate the growth of salt structures from the time of salt deposition through to the end of structural growth, in all tectonic settings.

Finite-element model

Finite-element model showing overpressure ratio next to rising salt structure. Courtesy of Mahdi Heidari.

The research is supported by a consortium of 36 oil companies and seismic-data vendors. These companies are interested in the research because they need to interpret salt structures correctly in hydrocarbon-rich salt basins, and because they need to be able to predict stresses and fluid pressures to drill wells. AGL research thus helps companies find and produce oil and gas around salt more efficiently and safely. It also gives us the opportunity to study fascinating natural systems.

AGL annual meeting

AGL Attendees at the 2015 AGL annual meeting.

Name of Research Consortium: Applied Geodynamics Laboratory (AGL)

Date of project start: 1988

Term of project:  ongoing

Project PI:  Mike Hudec

Other key personnel: Tim Dooley, Maria Nikolinakou, Oliver Duffy, Mahdi Heidari, Nancy Cottington, Naiara Fernandez, Maggie Curry

Principal information contact:

Funding sources: Industry

Other key partners and collaborators: Chris Jackson (Imperial College, London), Frank Peel (National Oceanography Centre, Southampton), John Snedden (UT Austin), David Mohrig (UT Austin), Wonsuck Kim (UT Austin), Ian Norton (UT Austin), Jaume Vergés (Institute of Earth Sciences Jaume Almera, Barcelona), Gill Apps (BP, retired)

Geographic areas of study: Gulf of Mexico, South Atlantic Salt Basins, North Sea, Precaspian Basin

General discipline of study: salt tectonics

Keywords: salt tectonics, structural geology, physical modeling, numerical modeling, regional geology