John C. Crelling
Written by Sue M. Rimmer
TSOP Newsletter 35 (4)

John Crawford Crelling, a renowned coal petrologist, passed away on September 27, 2018. Jack, as he was known to family, friends, and colleagues from around the world, was a consummate professional, a dedicated teacher and mentor, and an insightful researcher. He was born in Philadelphia, PA on June 13, 1941. He received a B.A. in Geology in 1964 from the University of Delaware, and an M.S. (1967) and Ph.D. (1972) in Geology from The Pennsylvania State University. He was also a Captain in the Army Corps of Engineers (1968-1970) where he taught at the Army Engineer School (Ft. Belvoir, VA) and served in Viet Nam where he commanded the 579th Engineer Detachment (Terrain Intelligence) and earned the Bronze Star.
Following his Ph.D. studies, Jack worked for five years in charge of the Coal and Coke Section at the Homer Research Laboratory, Bethlehem Steel. Here, Jack developed his life-long research interest in cokes and the controls on coke quality and properties. This was a significant step in his development as a researcher and, incidentally, an interesting segue from his graduate studies where his M.S. research had been on the coal/coke petrology of natural cokes in the Purgatoire River valley, and his Ph.D. on igneous petrology of dikes in the Spanish Peaks area in southern Colorado. While at Bethlehem Steel, Jack conducted research on the effects of coal weathering on coke quality. This early work led the way for many projects on coking as he moved on in 1977 to a teaching position in the Geology Department at Southern Illinois University Carbondale (SIUC).

Jack worked his way up the ranks at SIUC, from Assistant Professor (1977-1981), to Associate (1981-1987), to Full Professor (1987-2006). Following his retirement, he held the position of Research Professor (2006-2018). During his time at SIUC, Jack developed a world-class coal laboratory, working over the years with many faculty within the department (including Professors Dutcher, Jobling, Kruge, Anderson, and Rimmer) along with numerous visitors to his lab from the around the world. Jack recognized the importance of visiting other labs (such as at the University of Utah and Imperial College, London, UK) and hosted many visitors to his lab in Carbondale. He had collaborators in the United Kingdom, France, Spain, Canada, Pakistan, Japan, China, the Czech Republic, and the Netherlands, among others. He developed a strong association with the University of Newcastle-upon-Tyne in the UK, especially with Dr. Harry Marsh and his research group, with Jack visiting Newcastle several times and spending a memorable sabbatical there in 1991. The visits were reciprocated when Harry Marsh had an extended stay in Carbondale in the early 1990's.

Over the years, Jack developed a broad-ranging research program that included studies on western coals, spectral fluorescence, coking coals and cokes, reactivity of coals and coal macerals, and properties of chars, carbons, and graphites. Perhaps one of his most important efforts was the establishment of a density-gradient centrifugation (DGC) laboratory.

This is a technique borrowed from the biological sciences and allows separation of pure macerals (and other carbon components) based on their different densities. Today, primarily as a result of Jack's efforts, SIUC runs the only DGC lab in the US (and possibly worldwide) that is currently dedicated to coals, kerogens, and other carbon materials.

During his career, Jack published close to 120 peerreviewed papers, meeting proceedings, shortcourse notes, and book chapters; he also co-edited three book volumes, one of which "Applied Coal Petrology" (with Isabel Suárez-Ruiz) was awarded the 2009 Ralph Gray Award for Outstanding Book in Coal and Organic Petrology by The Society for Organic Petrology. Jack also had an exceptional funding record to support his research, bringing in close to $6.4 million in over 70 grants. His significant contributions to our science were recognized by numerous international organizations: Jack was honored with the 2001 Cady Award (Coal Geology Division of the Geological Society of America), the 2002 Joseph Becker Award (Ironmaking Division of the Iron and Steel Society of AIME), the 2007 Reinhardt Thiessen Medal (International Committee for Coal and Organic Petrology), and the 2015 Castaño Award (The Society for Organic Petrology). Similarly, at SIUC his research was recognized, and he was awarded the 1987 Outstanding Researcher Award from the College of Science.

Jack also played important roles in the leadership of our national and international professional organizations. He was involved with The Society for Organic Petrology (TSOP) since the early days, serving in several leadership roles including President. He was also heavily involved in the leadership of the Coal Geology Division of the Geological Society of America. His contributions to these and other groups led to Outstanding Service Awards from The Society for Organic Petrology (2004), American Chemical Society Fuel Chemistry Division (1994, 2003), and the Geological Society of America Coal Geology Division (1995).

Jack was equally renowned as a teacher, earning the SIUC College of Science's Outstanding Teacher Award in 2006. He presented extremely well organized and well received classes at SIUC, and his teaching portfolio included a wide variety of courses from introductory geology, to courses on planetary geology, coal geology, coal petrology, and even terrain analysis and forensic geology. He also took new graduate students and helped them develop their own teaching skills as they became Teaching Assistants. During his time at SIUC, over 40 students worked on theses and dissertations in the areas of coal petrology and organic geochemistry at SIUC; close to 30 of them were Jack’s advisees and they have gone on to successful careers in industry and government. As part of his efforts to share his knowledge, Jack developed and presented numerous short courses and workshops in organic petrology and coal geology. He also developed the first on-line atlas of coal and carbon petrology, one that continues today as "Crelling's Petrographic Atlas of Coals and Carbons"

Even in retirement, Jack continued to be active and came into the department on a regular basis. He would give guest lectures in Organic Petrology and Coal Geology and was always available to talk with students about their research projects.

Beyond remembering Jack for his scientific and academic contributions, we will also remember him for his strong sense of family. He loved to talk about his life-long partner, best friend and wife Betty, his wonderful sons Ian and Jamie, and in recent years would delight in sharing the latest pictures of his grandchildren Emma and Matheson. Jack seemed to hit the right work-life balance with diverse outside interests including a long-standing love of Sherlock Holmes, his beliefs (he was a life-long Episcopalian), and time spent with many friends and family. Those of us in the department here at SIUC will miss not only his scientific insights, but also his friendship and mentorship.