Chapter from: M 65:  Salt Tectonics: A Global Perspective
Edited By 
M.P.A. Jackson, D.G. Roberts, and S. Snelson

Structure, Tectonics, Paleostructure

Published 1995 as part of Memoir 65
Copyright © 1995 The American Association of Petroleum Geologists.   All Rights Reserved.
 

We thank all the far-flung attendees, who converged on Bath for the Hedberg International Research Conference, for contributing so much to the success of the meeting. We also express our appreciation to all the institutions and companies that supported the attendees, provided time for research, and released vital data--especially the major new regional syntheses in this book. We thank British Petroleum for generously donating funds that subsidized the costs of some speakers from academia who otherwise could not have attended the meeting. We are grateful to Debbi Boonstra, who handled the registration and logistics for the conference, and Bob Millspaugh, who represented AAPG at Bath. The conference was opened and closed by D. G. Roberts and sessions were chaired by M. P. Coward, F. A. Diegel, A. D. Gibbs, S. G. Henry, R. G. Hickman, J. R. Hossack, M. P. A. Jackson, J. Letouzey, K. R. McClay, D. G. Roberts, S. Snelson, P. Szatmari, C. J. Talbot, and S. Wu.

To all the authors that contributed to this book, thank you for the countless hours spent toiling on manuscripts while stretched by other demands and for your efforts to comply with the editing and reviewing schedule. Each chapter was reviewed by another author and by "outside" experts in certain aspects of salt tectonics. Accordingly, we would like to thank the following reviewers for invaluable assistance in the onerous task of reviewing the manuscripts.

Finally, it has been a rewarding and pleasurable experience to collaborate with AAPG's highly professional production staff, especially Anne Thomas and Kathy Walker.

Martin Jackson

David Roberts

Sig Snelson

Thirty years ago, a symposium on "Diapiric and Related Structures" formed part of the 1965 AAPG Annual Meeting in New Orleans. The resulting collection of papers was published as the classic Memoir 8, Diapirism and Diapirs, edited by J. Braunstein and G. D. O'Brien. Until now, this was the last AAPG book that focused on salt diapirs, although many papers continued to be published in the Bulletin. Since 1965, the data base of salt tectonics has evolved at an accelerating rate based on field observation, seismic interpretation, and advanced structural modeling. These findings and the recognition of the exploration importance of salt tectonics in more than 80 basins worldwide indicated that another global attempt to unravel the complexities of salt tectonics was long overdue.

In August 1990, AAPG's Science Director, Gary Howell, first suggested to one of us the idea of holding a Hedberg International Research Conference on "Salt Tectonics" with worldwide scope. After a formal meeting with him in May 1991, the three compiling editors accepted the task of convening the symposium, which was held in Bath, U.K., on September 13-17, 1993.

The timing of this conference was propitious. The preceding four years had seen an explosive expansion in papers dealing with salt tectonics. In particular, this field of study had just passed through a major conceptual breakthrough based on three-dimensional seismic data and innovative kinematic and dynamic modeling of salt tectonics. The objective of the conference was to highlight and share these advances in understanding the structural geology and tectonics of salt structures at seismic scales in the context of hydrocarbon exploration and development, including classic areas having abundant data as well as lesser known basins characterized by newly discovered structural styles. Of special interest were newer aspects of salt tectonics that were unknown at the symposium 30 years ago. These included controls on the shape and structural evolution of salt structures, especially the style and rate of sedimentation; the influence of faulting in extensional, contractional, transtensional, transpressional, and inversion regimes; emplacement of allochthonous salt sheets and canopies and their subsequent segmentation and redistribution; the creation of salt welds and fault welds; and the vernerable but previously neglected field of contractional salt tectonics.

The program of the Bath conference was the largest and most comprehensive ever dealing with salt tectonics. Some 46 papers were presented orally and another 34 displayed as posters interspersed with discussion sessions that continued well beyond the day's proceedings. Invitations to the 75 attendees were deliberately skewed to attract a majority of contributions from industry to ensure release of abundant new geological and geophysical data of high quality. As a result, the papers spanned a broad range, covering state-of-the-art seismic imaging, restoration techniques, and mechanical modeling followed by examination of salt tectonics (and some shale tectonics) in the following regions: Gulf of Mexico, Arctic Canada, Barents Sea, North Sea, Spain, Mediterranean Sea, Algeria, Tunisia, Red Sea, Iran, Pakistan, Kazakhstan, Caribbean, Angola, Gabon, and Brazil. The conference was notable for the wealth of new data and novel ideas offered through formal presentations and informal discussions among attendees. During the conference, many attendees expressed a wish to see a fuller collection of papers published rather than the volume of extended abstracts available only to attendees. Accordingly, they were asked to respond to a subsequent questionnaire in which they strongly reconfirmed their earlier wish to see publication of a collection of full-length papers as an AAPG Memoir.

This volume is the result. To ensure prompt publication of an affordable book, the length was restricted to 21 chapters (coincidentally the same number of papers as in Memoir 8) out of the 80 papers presented at the conference. Not all the presenters were able to contribute full-length papers, but nevertheless we were able to be highly 
selective in choosing papers that highlighted key advances in salt tectonics. Our choice 

preserves the wide geographic coverage of the conference and includes both detailed regional syntheses of classic areas, such as the Gulf of Mexico and the North Sea, as well as preliminary investigations of equally fascinating but less-explored regions of salt tectonics, such as the deep-water Santos Basin (Brazil), offshore Yemen (Red Sea), Parry Islands (Arctic Canada), and the Nordkapp Basin (Barents Sea). We hope that the investigations of salt tectonics presented in this volume will serve as classic examples of a wide range of structural styles involving evaporites. We also offer these examples as case studies that can be applied as guides to petroleum and mineral exploration in other salt basins around the world. With this broad scope, this book is entitled Salt Tectonics: A Global Perspective. 

The organization of the book has a structure similar to that of the Bath conference. A historical review chapter is followed by four chapters on section balancing and modeling (later chapters also incorporate modeling research, but their focus is more geographic). The next 16 chapters are organized along geographic lines in loose order of their current hydrocarbon production, from the Gulf of Mexico, where mature exploration has been invigorated by the subsalt play, to remote reaches of the Arctic Ocean, where exploration is in its infancy.
 

Martin Jackson, David Roberts and Sig Snelson