GSA Medals & Awards

Penrose Medal

Peter R. Vail
Peter R. Vail
Rice University

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Presented to Peter R. Vail

 Citation by Robert M. Mitchum

Mr. Chairman, I am greatly honored to introduce Peter R. Vail, the GSA Penrose Medalist for 2003. When Peter Vail introduced the concepts and applications of sequence stratigraphy, the effects on stratigraphic geology and seismic interpretation were comparable to those of plate tectonics on structural geology. Pete's ideas on the unifying paradigm of eustatic cycles are probably as close to an original concept as most of us are privileged to see. Pete's worldwide experience with Exxon's exploration groups honed the concept into an immensely practical tool for hydrocarbon exploration and stratigraphic studies in general.

Pete was born in New York City in 1930. He graduated from Dartmouth College in 1952. He attended Northwestern University from 1952 to 1956 for his M.S. and Ph.D. degrees. At Northwestern, where I first knew him, he was greatly influenced by Professors Larry Sloss and Bill Krumbein, with their ideas on quantified facies mapping and unconformity-bounded cratonic sequences.

Pete began his career with Exxon in 1956 as a research geologist with the Carter Oil Company, an Exxon affiliate in Tulsa, Oklahoma. He and his lovely wife Carolyn reared a family of three children, who at first grew faster than his reputation. He relocated to Houston in 1965, at Esso Production Research Company, now ExxonMobil Upstream Research Company, and advanced to senior research scientist, the highest technical position.

In 1986, Peter was appointed the W. Maurice Ewing Professor of Oceanography at Rice University in Houston, where he has been a great influence on the lives of many students. In 1992-1993, during a sabbatical leave to France, he led studies of the sequence stratigraphy of European basins and revised and documented the eustatic cycle chart. He became professor emeritus at Rice in 2001 and still actively consults in Houston.

Pete's ideas evolved naturally from his first pioneering work on the importance of stratal surfaces in rocks as geologic time lines. He soon recognized the cyclic occurrence of bundles of strata he called sequences in well logs, seismic reflections, and outcrops. Observing that sequence boundaries appear synchronous globally, he postulated that cyclic eustatic sea level changes are major controls on stratigraphy, along with basin tectonics and sediment supply. Eustatic cycle charts, seismic facies analysis, and the accommodation model of cyclic deposition were developed as applications.

In 1975, the first outside presentations of these concepts were made, appropriately, at a GSA convention. In 1977, these concepts were published in American Association of Petroleum Geologists Memoir 26 as the first of many articles and memoirs.

All the early stratigraphic ideas were generated in the fertile brain of Peter Vail as spinoff from mapping and stratigraphic projects. Early studies involved well logs and outcrops, one of which was a study of the famous Eocene-Miocene unconformity in the Maracaibo Basin of Venezuela. Here Pete recognized Miocene onlap and facies changes in well logs. Many of the concepts of beds and bedsets are due in great part to the ideas of C.V. (Chuck) Campbell, an early co-worker.

Pete soon recognized the potential of seismic reflection data in stratigraphic interpretation. Against the advice of his supervisors, he transferred to geophysics and began work on the significance of seismic reflection patterns. One of his major premises was that seismic reflections follow geologic time lines of detailed physical bedding surfaces, rather than massive time-transgressive formational boundaries where the strongest impedances occur. This concept challenged commonly accepted ideas, and was widely questioned in the company.

His early years in geophysics were very difficult times for Pete. The value of his work was not recognized, and he was ranked very low in geophysical technical appraisals. In addition, he was subject to ridicule and opposition from other geologists as well. One well-known Exxon geologist, in his ridicule, goaded the audience in a large technical meeting into howls of laughter on how the seismic reflections must bounce off the backs of fossils. In spite of this opposition, Pete persevered almost single-handedly in showing the relationship of seismic reflection patterns to chronostratigraphy. This was the "Eureka!" event for Pete, because it showed that seismic data could be used for putting stratigraphy into a geologic time framework for mapping.

About 1965, Pete's work was recognized enough to establish a very dedicated and enthusiastic seismic stratigraphy research group. This was a very fertile period of exponential growth. Worldwide cycle documentation and exploration applications were tied into Exxon's worldwide exploration of continental shelves and slopes. Seismic facies interpretation was systematized, cycle charts evolved rapidly, computer applications and mapping techniques were expanded, and biostratigraphy was improved. In 1978, the accommodation model and the concept of systems tracts allowed interpretation of sequences in well logs and outcrops as well as on seismic data. This broadening of interpretation beyond seismic data led to the name change to sequence stratigraphy.

In 1977, AAPG Memoir 26 was published, marking the first outside publication on seismic stratigraphy. Exxon's contribution to this publication was released only after all exploration managers agreed that seismic stratigraphy had gone about as far as it could go in Exxon. Almost immediately after Memoir 26 was published, these same managers closed the door on outside publication for a long time after they began getting phone calls from other companies complimenting Exxon's generosity in releasing these concepts.

Pete has held many important roles in a variety of industry, government, and academic steering committees. He has been awarded the AAPG Sidney Powers Memorial Award, the Virgil Kauffman Gold Medal of the Society of Exploration Geophysicists, the AAPG President's Award and Matson Award for best papers, the Individual Achievement Award from the Offshore Technology Conference, and the Twenhofel Medal by SEPM-Society for Sedimentary Geology. His extensive publications and scientific citations indicate the significance of his research.

Above all, Pete's greatest characteristics still remain his integrity, his dedication to his family, and his faithfulness to friends, colleagues, and students. I consider it a great honor to have been part of his life. Ladies and gentlemen, let me present Peter R. Vail.

 top 2003 Penrose Medal - Response by Peter R. Vail

First, I want to thank the GSA committees and members who made it possible for me to receive this prestigious award. I also want to acknowledge and thank my colleagues who worked with me developing the concept and applications of sequence stratigraphy.

The roots of sequence stratigraphy started with a well log project in which John Sangree, Chuck Campbell, and I correlated what we then called marker beds. We developed a series of stratal patterns including offlap, downlap, and onlap. I showed these patterns to a seismic interpreter, a friend of mine named Paul Tucker, who told me one could see all these patterns on seismic data. He invited me to his office to see for myself. I was impressed and decided I should join the Geophysical Research Department.

To everyone's surprise, in the early 1960s I did manage to transfer but I found I had joined a group of theoretical mathematicians and geophysicists. My group leader told me I had no future with the company. I just did not know enough mathematics. Fortunately, I had a good friend in the department named Frank Branisa, who labored long and diligently, teaching me frequency spectra, bandwidth, and deconvolution.

During this period in the Geophysical Research Department, I learned of an Exxon well that was drilled on a structure basinward of a well that drilled a thick sand. The seismic reflection that coincided with the sand top was traced basinward across the structure by the Exxon interpreter, where he predicted the sand to be present, but the well found only shale and silt, and no sand. Why did this happen? No one seemed to know. I thought this would be a great project for me. Fortunately, management agreed.

After receiving the logs and seismic data, I decided the only way to solve this problem was to do the paleontology to determine the ages for the reflection interval in both wells. I managed to find Lou Stover, an Exxon paleontologist, who was available to work on the project. He found that the sand in the landward well was the same age as the correlative silt and shale on the basinward well with the structure. To test the idea that the reflection was following the geologic time lines and not the top of the thick sand, I contacted Frank Branisa to see if we could build an impedance model and simulate a seismic section from it. Exxon Research had an analogue equalizer machine that would suit the project just fine. I built a geological impedance cross section between the two wells. Frank produced a synthetic seismic section using a pulse that matched the cycle breath on the seismic section. He found that the synthetic reflection and the time lines-not the facies-change from sand to shale.

After this, we made several more synthetic sections for different areas where we knew there were major facies changes from our early well log correlation work. Two examples are published in American Association of Petroleum Geologists Memoir 26, section 5 (Payton, 1977). All of the synthetic examples showed a high-amplitude reflection on top of the sand. This reflection carried to the equivalent shale in the other wells, but lost amplitude. The high amplitudes stepped down or up to other reflections that followed the facies change from sand to shale. These examples supported the concept that seismic reflections tend to follow the time synchronous stratal or bedding surfaces rather than facies.

Following this discovery, I gave many talks where I was commonly ridiculed. One senior geologist accused me of proposing that the reflections were bouncing off the backs of fossils. Another suggested that I was telling him that what he was teaching his students was wrong. Time and experience prevailed, and now it is a well-accepted concept.

In the early 1960s, Exxon Research established a seismic stratigraphy section in the Geophysical Department with Mandy Touring as group leader. Other members were Howard Yorston, an experienced seismic interpreter; John Sangree, from the reservoir geology group; Mike Widmier, a geologist from Exxon operations; Bob Wilbur, a research geologist; Janet Teagarton, a computer programmer who later became Janet Wilbur; and me. This diversified group worked well together until, regretfully, Mandy Touring became ill. I was then appointed section supervisor.

Our approach to research, originally proposed by John Sangree, was to hold periodic meetings where we would suggest worthwhile research ideas as if we had unlimited funds. We would then discuss these ideas among ourselves and decide who would work on what. I was especially interested in stratal patterns we had identified in our early well log correlation work, so I continued to work on this project on high-quality seismic data from basins around the world. What I observed first was that the widespread unconformity surfaces characterized by onlap were the most logical to subdivide the section into major genetic intervals. As I observed these onlap surfaces and dated them with paleontological information, I found that the surfaces had the same ages and similar patterns in most basins around the world. In order to convey this observation, I drew a series of onlap charts that we converted into eustatic sea-level charts. While working on a project in the North Sea, I also observed genetic sedimentary packages we came to call sequences.

Bob Mitchum returned in 1969 from a two-year assignment in Midland, Texas. Upon his return to Exxon Research, he joined our group and became involved in many of our major interpretation projects before becoming the major author of American Association of Petroleum Geologists Memoir 26. In the mid 1970s, Jerry Baum, working on a thesis studying the Tertiary of the Atlantic coastal plain, recognized similar age sequences in his thesis area. When he graduated, he applied for and received a position with our group. In 1980, Rick Sarg joined our group to work on carbonate seismic stratigraphy. We then moved into a new building and our seismic stratigraphy section became the seismic interpretation section with Bob Todd as supervisor. At this time, I became a technical advisor and worked on a variety of projects. In one of these projects, I worked with Jan Hardenbol, Bilal Haq, and others to build the global cycle charts.

In 1986, after 30 years with Exxon Research, Rice University offered me a position as the Maurice Ewing Professor. This started my second career, one that I enjoyed greatly. I had many talented graduate students who added greatly to our knowledge of the global distribution and ages of sequences. During a sabbatical leave, my colleagues and I tested our concepts in the classical European basins. This study resulted in the publication of Society of Economic Paleontologists and Mineralogists Memoir 60, which documented and updated the global cycle charts. After 15 years with Rice, I started my third career, retirement, with a wonderful kick-off party called the Vail Fest, sponsored by Rice and Exxon. I received many wonderful compliments. My kids responded by saying, "If you're so smart, why don't you find us some oil?" That sounded good to me, so besides consulting, I decided to invest in some oil and gas wells. So far, I've been on a learning curve. I've learned that just because you find some oil or gas, it is not a discovery until you make money. And now, finally, I am beginning to get some return on my investments from several of the wells.

Again, let me thank all of your for this great honor.