John M. Armentrout, 2009 Doris M. Curtis Medal
John M. Armentrout ‘arrived’ in the Gulf of Mexico in 1985 when Mobil Oil Corporation assigned him to Mobil’s Deep-Water Task Force, evaluating the acreage leased in the first area-wide sale. This began a career-long quest to understand the stratigraphic history of the Gulf of Mexico Basin utilizing biostratigraphic data as a pivotal tool. John’s Gulf of Mexico publications include the topics of biostratigraphy, sequence stratigraphy, computer simulation of stratigraphic geometry, source-rock geochemistry, and sedimentology of gravity-flow facies. Additionally, John has served the Gulf Coast community as program-chair and editor for the 1990, 1993, and 2002 GCSSEPM Annual Bob F. Perkins Research Conference proceedings and as GCSSEPM President in 1993. He was elected to GCSSEPM Honorary Membership in 1999.
A significant part of John’s career success can be attributed to optimizing the impact of biostratigraphic data provided by the co-workers and many colleagues with whom John worked during his 35-year petroleum industry career. At Mobil, John’s introduction to Gulf Coast stratigraphy was facilitated by several knowledgeable co-workers who had experience in using palynology, calcareous nannoplankton, and foraminifera in solving stratigraphic problems.
Initial Gulf of Mexico work focused on the East Breaks 160-161 Field where preliminary interpretations of the reservoir as a deltaic deposit was challenged by biostratigraphic reports of interbedded bathyal biofacies. The regional integration of well logs, seismic record sections, core sedimentology, and biostratigraphic data clearly demonstrated the deep-water gravity-flow depositional environment for the productive facies. The studies confirmed that the reservoir was deposited as a slope mini-basin fan down-dip from a lowstand shelf-margin delta. This work, published in 1987 in the GCSSEPM Foundation 8th Annual Bob F. Perkins Research Conference Proceedings, marks the beginning of John’s association with the GCSSEPM.
Recognizing that the addition and integration of planktonic foraminifera and calcareous nannoplankton data to the tool-kit of biostratigraphers afforded a major improvement in stratigraphic resolution, John later requested Mobil’s permission to take the synthesis project into the public domain. This resulted in an SEPM sponsored project documenting the utility of foraminifera and calcareous nannofossils for regional correlation and sequence stratigraphic analysis, published in the 1990 GCSSEPM Foundation 11th Annual Bob F. Perkins Research Conference Proceedings. In a very real way, this effort was built upon the pioneering work of Curtis, Picou, Tipsword, and many other paleontologists working the Cenozoic stratigraphy of the oil-rich Gulf basin. This synthesis project, coordinated by John and J. Fred Clement, and funded by several exploration companies, resulted in several publications in the 1991 GCSSEPM Foundation Bob F. Perkins Annual Research Conference Proceedings, as well as synthesis papers in the 1991 Seismic Facies and Sedimentary Processes of Submarine Fans and Turbidite Systems edited by Marty Link and Paul Weimer.
John’s involvement with the GCSSEPM led to friendships with many of the consulting biostratigraphers and those working for major oil companies. As industry began another wave of staff reductions in the early 1990’s, biostratigraphers took an especially hard-hit. John became a champion of biostratigraphers and biostratigraphic analysis, assembling examples of high-impact biostratigraphy versus the demographics of biostratigrapher employment. This effort lead to both website data files and a paper documenting this history in the 1997 International Senckenberg Conference Proceedings on ‘21st Century Biostratigraphy,’ and the value-added by biostratigraphy to both exploration and production in papers published in the Geological Society (London) Special Publications No. 104 (1996) and No. 152 (1999).
As GCSSEPM President in 1993, John championed the concept of a synthesis of Gulf of Mexico Neogene “Index Marker” that was subsequently implemented by Ed Picou with project coordination and compilation by Rashel Rosen (foraminifera), Michael Nault (biostratigraphic chart), and principle editing by Norman Rosen. This spectrum of leaders, supplemented by many contributors, is typical of the cooperation of the Gulf of Mexico biostratigraphic community, and is reflected in John’s publications, almost all of which were co-authored with a range of specialists.
In 1997-98, toward the end of John’s 26-year career with Mobil, he participated in a synthesis of depositional cyclicity and reservoir analysis for the regional area around Auger Basin, working with a team integrating 3D seismic calibrated by biostratigraphic and biofacies analyses. This integrated study contributed to a team endorsement to participate in the Thunderhorse exploration well.
Following retirement in 2000, John applied his experience from the northern Gulf of Mexico to the area of the Mexican Ridges for PEMEX and to offshore Suriname for Statoil. In both efforts, the championing of high-resolution biostratigraphy continued to be a significant part of John’s contribution.
As a teacher, John’s course in sequence stratigraphy may well be the best presented and the most practical work available. Of particular importance are his anecdotal comments during the course; these remarks present priceless insights into how to solve stratigraphic problems and show his willingness to share his knowledge with others.
On a personal note John has always been willing to participate in any meetings we felt his presence was necessary; although sometimes late and with his suitcase in hand, he always appeared and gave his speech. He is a very pleasant and easy going person with whom to work. Although not trained in paleontology, he has become a leader in championing micropaleontology; for this effort, those of us who have been trained in the subject owe him a great debt.
John’s contributions in writing, practice, and teaching confirm that he exceeds the requirements for receiving the Doris Malkin Curtis Medal. His influence on the understanding of deep-water sediments is undeniable. His many friends and colleagues join in congratulating John on receiving the prestigious Doris Malkin Curtis medal for 2009.
NCR & Associates