Charles & Nancy Naeser

Charles Wilbur (Chuck) Naeser (1940–2016)

By Barry Kohn

Chuck was born in the District of Columbia, where his father, Dr. Charles R. Naeser, was a longtime professor and chairman of the Chemistry Department at George Washington University. Chuck graduated from Falls Church High School in Virginia in 1958, obtained an A.B. in geology from Dartmouth College in 1962 and an M.A. in 1964, and in 1967 a Ph.D. from Southern Methodist University (SMU) in Dallas, Texas.

Following in his father’s footsteps, he started out as a chemistry major during his undergraduate studies at Dartmouth College, but by his junior year had switched to geology. While an undergraduate student, Chuck’s early research experience involved summer vacation geochemistry projects, including water quality analysis at the U.S. Geological Survey (USGS) and the National Bureau of Standards. During his master’s program, he organized and set up a water analysis laboratory at Dartmouth College supervised by Noye Johnson. The laboratory was set up to analyze water from the Hubbard Brook project, which was one of the first to identify ‘acid rain.’

While working towards his master’s degree, Chuck sat in on a short course on isotope geology presented by Henry Faul, and Chuck was clearly intrigued by this topic. Henry at that time was based at the USGS, but he had recently accepted a job at SMU. One thing led to another during that short course and Henry invited Chuck to enroll at SMU for his Ph.D. Henry had recently heard a talk at the 1963 GSA Annual Meeting in New York on fission tracks by Fleischer, Price, and Walker, who were working at the General Electric Research Laboratory, and thought that might be an interesting subject for Chuck to explore for his degree. So he arranged for Chuck to work at the General Electric Laboratory under the supervision of Robert Fleischer in the summer of 1964. This led to the publication of papers on which he was a coauthor in Science and the Journal of Geophysical Research on fossil particle tracks in meteorites and tektites. This experience set Chuck off on a lifelong path of research in fission-track studies. He went on to pursue Ph.D. studies in nuclear geology under the supervision of Henry Faul at SMU on the first Ph.D. awarded in the geological sciences from that university and the first thesis on the application of fission-track studies to a geological problem, which in this case investigated the response of fission tracks in different minerals in the contact zone of a stock in Colorado. This work built a foundation for the rest of Chuck’s professional life and following the awarding  of the degree in 1967, Chuck went on to a 38-year career with the USGS. He was first based in Menlo Park, California, then in Denver for 22 years, and from 1993 at the USGS headquarters in Reston, Virginia, until his retirement in 2005. Beginning with his Ph.D. thesis, Chuck was a pioneer in the field of fission-track thermochronology, which was in its infancy at that time. At the USGS, he was fortunate to be able to apply his skills to a range of geological problems, in collaboration with geologists both inside and outside of the USGS. Working with geologists to solve different problems paved the way for him to develop many practical techniques of the method and new wide-ranging  geological applications that are now used in laboratories around the world. Highlights of Chuck’s research accomplishments include:

  • Development of the techniques for the routine dating of sphene, zircon, epidote (and allanite), and garnet, as well as carrying out some of the earliest laboratory annealing studies on apatite, sphene, and epidote.

  • Recognition that different track annealing properties of multiple coexisting minerals from within the same rock could be used as a tool for elucidating thermal histories, and that integrating those data together with ages obtained by other geochronology methods was a powerful strategy for reconstructing geological/tectonic histories, e.g., in contact zones and deep boreholes.

  • One of the first to observe a correlation between apatite fission-track age and elevation, which led to the use of fission-track dating to determine the uplift/erosion rates of mountain ranges (e.g., Colorado Rockies). Günther Wagner at the Max-Planck Institute in Heidelberg working in the European Alps also made this observation independently, around the same time.

  • Development of new applications for fission-track dating including: -dating of volcanic ash layers and bentonites in sedimentary sequences, -dating of and exploration of hydrothermal mineralized systems using paleothermal anomalies (in one study a paleothermal anomaly map based on the pattern of apatite and zircon fission-track dates in the Rico District, Colorado, provided information key to the discovery of a buried, world-class molybdenum porphyry deposit), -direct dating of landscape evolution, by dating zircons in clinker formed by the natural burning of a coal seam, -dating of kimberlites and diatremes.

  • First to demonstrate that fission-track analysis could be used to study the thermal history of sedimentary basins. This area of fission-track analysis has led to the development of commercial fission-track laboratories in the United States, Australia, Great Britain, Norway, and Japan that have consulted for the hydrocarbons industry. This is in addition to several academic laboratories.

  • Studies on the long-term history of major faults that are still active and comparing their rates of displacement over time (e.g., uplift of the Wasatch Mountains along the Wasatch fault, Utah), providing important information for seismic hazard assessment.

  • Introduction of apatite and zircon from the Fish Canyon Tuff, Colorado, as key inter-laboratory fission-track standards.

During his career, Chuck also made broader contributions to the geoscience community through his scientific leadership. He was always generous with his time in tirelessly introducing other scientists to fission-track analysis through short courses and lectures and in mentoring students and professionals (often one-on-one) from the United States and many other countries (including Indonesia, Japan, Netherlands, Canada, France, Norway, New Zealand, Great Britain, Mexico, Argentina, and Venezuela) who came to his Denver laboratory to learn the ropes. This includes the authors of this Memorial. Chuck was an adjunct professor at Dartmouth College in the 1980s and University of Wyoming (1984–1995). He served as an advisor and examiner on many M.A. and Ph.D. theses from U.S. and overseas universities, and was an invited reviewer on countless manuscripts and research proposals. At the same time, he was an author on more than 210 professional works. While working at the USGS, Chuck also held several senior administrative positions, including associate branch chief, Branch of Isotope Geology, Denver; associate chief of the Office of Regional Geology; and program coordinator for the National Geologic Mapping Program at Reston. Chuck retired from his long and distinguished career at the USGS in 2005. Along with his wife, Dr. Nancy D. Naeser, he remained research-active as a scientist emeritus at the USGS in Reston until the time of his passing.

In recognition of his work, Chuck was a worthy recipient of several honors and awards. He received the Schuler Geology Prize, Southern Methodist University (1966), was elected a Fellow of the Geological Society of America (1974), received the Colorado Scientific Society 1980 Best Paper Award, was selected by Life magazine as a member of their hypothetical, ideal 15-person international team to study the origins of early man (December 1981 issue), was awarded the Department of Interior Meritorious Service Award (1993), as well as USGS Star awards (1996, 2000, 2001, 2003). In September 2016, at the 15th International Conference on Thermochronology in Brazil, he became only the second recipient of the Laslett Prize, awarded by the International Standing Committee on Thermochronology for “exceptional contributions to the development and application of fission-track thermochronology in the geosciences.” He was elected as a councilor of the Colorado Scientific Society in Denver (1982–1984) and also served on the editorial board of Geology (1991–1993).

Appropriate for someone who spent his entire career in fission tracks, his other great passions were fishin’ and tracks (both actual trains and model trains, particularly G-scale garden railways). Rumor has it that he caught his first fish, in the Tidal Basin in Washington, D.C., at age 11 months, not long after he received his first model train set. He was treasurer of the Denver Garden Railway Society and spent many happy hours in Virginia running model trains for the annual holiday train shows at the USGS and Colvin Run Mill in Reston. He remained an avid fly fisherman all his life, in beautiful mountain streams and rivers from the Rocky Mountains to the Amazon, Atlantic Coast saltwater, and the farm pond outside his back gate in Virginia. He fished on cherished canoe trips to the Quetico Provincial Park wilderness in northwestern Ontario, beginning as a child with his family and ultimately spanning nearly 60 years and four generations of the Naeser family, to his son, son-in-law, and grandson.

Growing up in Virginia, Chuck was an Eagle Scout. He remained active in Scouts in the 1980s, as assistant scoutmaster of BSA Troop 499 in Lakewood, Colorado. He enjoyed skiing since his earliest days at Dartmouth College, where he was a manager for the ski team. His last ski day, at age 75, on Easter Sunday 2016, with his son at Copper Mountain west of Denver, was some of his “best skiing in years”—beautiful day, perfect snow. And like so many geologists who spend time outdoors, he enjoyed birding. Following retirement, he and Nancy spent time in Arizona, watching birds and generally thriving on their love of the west.

Chuck passed away on 18 November 2016, after a short illness and is survived by his wife Nancy; daughter Christiana Naeser Zelloe (Joseph J. Zelloe), son Robert B. Naeser (Hilarea Amthauer), and their mother Barbara S. Naeser; sister Dr. Margaret A. Naeser; four grandchildren (Jack, Molly, Oscar, and Vivian); and aunt Anne Naeser. He will be remembered for his significant contributions to the development and application of fission-track analysis in the geosciences, as a generous mentor, a good friend to all who came to know him, and a loved and greatly missed member of his family.

Nancy Naeser

Chuck and Nancy Naeser in the field, New Mexico, 1983.

Nancy Naeser first worked for the United States Geological Survey (USGS), in the Branch of Astrogeology in Flagstaff, Arizona, in the summer-fall of 1966, after graduating from the University of Arizona with a BS in Geology and before going to New Zealand on a Fulbright Scholarship in early 1967.  Part of her work in Flagstaff was finishing a preliminary geologic quadrangle map of the moon that she began while still at the University of Arizona (Cozad and Titley, 1968).  “It was a great time to be at the Survey in Flagstaff, with astronauts coming through for training in preparation for the first lunar landing”.

Nancy was originally slated to be in New Zealand for the standard 9-month term of a Fulbright, but that eventually turned into 9 years, as she expanded her Fulbright study into a Ph.D. and then worked as the Assistant Editor of the New Zealand Journal of Geology and Geophysics for 2-1/2 years.  Her Ph.D. thesis dealt with the ash-flow tuffs of the Central North Island, with emphasis on lateral variations in welding and crystallization in one of the largest units, the Whakamaru Ignimbrite. At the same time, two fellow graduate students, Diane Seward and Barry Kohn, were studying the widespread air-fall tephras of the North Island. Those tephras had eluded most attempts to date them—until Diane and Barry came across an early abstract written by Chuck on dating tephras using fission tracks.  They went on to use fission tracks to successfully date their air-fall tephras.  After completing her thesis Nancy began learning the fundamentals of fission track dating from Diane Seward, using a microscope borrowed from the N.Z. Geological Survey and set up in Di’s livingroom—such are the beginnings of a career! 

During this time, John Westgate from University of Toronto came to New Zealand.  He had recently spent part of a summer in Denver, learning FT dating from Chuck and had set up a FT laboratory in Toronto.  He offered Nancy a postdoctoral fellowship at UT to date air-fall tephras, primarily in Alaska and the Yukon Territory, that were important marker horizons but had generally proven difficult or impossible to date by other methods.  Nancy arrived in Toronto in the fall of 1976 and in early 1977 John arranged for her to be part of a 2-week FT course that Chuck ran every year or so in his Denver laboratory.  Following that, with Chuck’s encouragement, Nancy applied for a USGS-National Research Council Postdoctoral Research Associateship, which took her to Denver and the USGS in 1979.  After the USGS-NRC postdoc ended in 1981, she began working as a research geologist for the Survey.  Chuck and Nancy were married in 1982, and remained in Denver until they transferred to Reston, Virginia, in 1993 when Chuck rotated into a temporary administrative position at the USGS Headquarters. Chuck retired in 2005 and Nancy a year later, but both remained active in research at the Survey as a Scientist Emeritus.

Nancy’s work in Toronto necessitated overcoming problems in dating young, fine-grained, low-uranium volcanic glass by the FT method (including the question of how to deal with glass shards that were so young and so low in uranium that no spontaneous tracks were observed in the counting area) and resulted in the first ages obtained for several of the important tephra marker horizons in Alaska and the Yukon Territory.  John Westgate and Nancy continued to collaborate on FT-dating of tephras and other tephra-related projects into the 1990’s. 

While still in Toronto, Chuck was in the process of publishing the paper that was the first to suggest that fission-track dating, particularly of apatite, could be used to determine the thermal history of sedimentary basins (C.W. Naeser, 1979).  Nancy’s USGS-NRC postdoc was designed to test the feasibility of the method.  The initial plan was to work on the Powder River Basin in Wyoming, but that was put on hold when, shortly before arriving in Denver, Chuck received the first of a suite of samples from the southern San Joaquin Valley (SSJV) in California from Thane McCulloh (USGS/Mobil Exploration and Producing Services). And the SSJV proved to be close to an ideal setting for showing that FT could indeed be used to determine the thermal history of a sedimentary basin.  The study was ultimately published in N.D. Naeser and others (1989, 1990).  Nancy then went on to use FT to study the thermal history of other basins, including the Green River (Wyoming), Powder River, Los Angeles (California), and Anadarko (Oklahoma) basins (e.g., N.D. Naeser, 1989, 1992; N.D. Naeser and others, 1996; Carter and others, 1998; also N.D. Naeser, 1993). 

“This was truly an exciting time as we, along with Andy Gleadow and his group in Melbourne, developed this application of FT and introduced it to our colleagues.”  As a result of a 1983 SEPM Research Conference that Nancy was invited to participate in, she was asked to organize an SEPM Research Symposium on methods for determining thermal histories of sedimentary basins for the AAPG Annual Convention in New Orleans in 1985 which led to publication of “Thermal History of Sedimentary Basins: Methods and Case Histories” (N.D. Naeser and McCulloh, 1989; N.D. Naeser and others, 1989).

During this time, although Chuck and Nancy were involved in a number of separate projects, they continued to collaborate on FT studies and on writing invited review articles and teaching FT short courses. “One of the most interesting of our joint research projects was in Pakistan in collaboration with Dartmouth, demonstrating that the FT ages of detrital zircons in sedimentary rocks can be used to interpret the uplift history of the source terrain, and showing that areas of high uplift rate and relief (comparable to the present-day Nanga Parbat area) have existed in the Himalaya for at least the past 18 m.y. (Zeitler and others, 1986; Cerveny and others, 1988).”  An important outcome of this study was developing the etching and counting procedures that would ensure, to the extent possible, that zircon grains representing the full spectrum of grain ages present in a detrital suite are properly etched and can be dated (N.D. Naeser and others, 1987).

“So basically, Chuck and I collaborated and pursued our own interests up until 1995.  At that point a major reorganization in the USGS put us back in the same Branch for the first time since my postdoc in Denver, eventually working together on the same projects, most notably applying FT to the Appalachians.” This work resulted in numerous talks and published papers with further publications still to come!