2003
Day Medal

Dennis V. Kent
Rutgers University

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Presented to Dennis V. Kent

 Citation by Neil D. Opdyke

Professor Dennis Kent is a specialist in the study of the magnetism of rocks, and in its application to a very wide range of problems in the earth sciences, magnetostratigraphy, chronostratigraphy, marine magnetic anomalies, history of the geomagnetic field, and tectonics. He excels because of his mastery in the laboratory and because of the imaginative manner in which he applies his knowledge. He has authored or co-authored over 200 publications and is cited by Science Watch as having the second highest citation index worldwide among solid earth scientists.

Kent's contributions to tectonics have been of great importance He has demonstrated that the great arc of the Appalachians is a result of bending in plan taking place during the late stages of the Appalachian Orogeny. The result is based on careful high-temperature demagnetization of red Paleozoic formations in the Appalachian basin . His fact-based advocacy of the mobility of the various components within Pangea is vital to any understanding of late Paleozoic geology and history. These studies are ongoing.

A seminal contribution has been his work on time scales for Jurassic and later time (<175 m.y.) using a reevaluation of marine magnetic anomalies with Cande, which led to his development of a new Chron nomenclature now in use and an integrated magnetobiochronologic timescale for the past 75 m.y. These studies began in the 1970s and continue to this day.

Kent has produced a complete magnetic stratigraphy for the Newark System sediments in New Jersey which spans Middle and Late Triassic Epochs . This monumental study required the sampling and measurement of 7 km of sediment core requiring the complete thermal demagnetization of thousands of samples. It also required the development of a novel method for orientation of the bore core using the magnetic overprint. The magnetic stratigraphy has been dated by astrochronology and calibrated by radiometric dates. He is extending this work into the lower Jurassic of Connecticut and lower Triassic of the Mediterranean region. The magnetic stratigraphy of the Newark basin has subsequently been used to correlate and date the other Triassic basins of eastern North America

Kent has very broad interest in the Earth and its history. His first paper was on ice-rafted sediments in the North Pacific, and recent papers have covered topics such as the uplift of Florence (Italy) and a possible meteorite impact at the Paleocene/Eocene boundary. He has demonstrated that the variation of the amplitude of the central magnetic anomaly <(800,000 yr) across strike is caused by variations in the strength of the main geomagnetic field and along strike to variations in mineralogy. His work on the magnetism of marine cores has yielded a data set that is widely used in models of the Earth's magnetic field.

Dennis brings a sense of gravita to his work — surprising perhaps in one so young. I have heard it said that he has a forbidding scowl, but that is a mistake, it is not a scowl; it is just that he is deep in thought grappling with some complicated Earth problem. Dennis richly deserves the Day Medal.

  2003 Arthur L. Day Medal - Response by Dennis Kent

Thank you, Neil, for the generous encomium. I feel overwhelmed and thrilled to receive this honor, especially coming from the professional society that I have belonged to the longest and that published my first paper more than 30 years ago when I was a graduate student. I am deeply grateful to the officers and friends of the Geological Society for making this wonderful occasion possible.

It has been my continuing great pleasure to work in the discipline of paleomagnetism, which admirably bridges geology and geophysics. Paleomagnetism is a young field, making it possible for me to have known many of its founders, such as the late Keith Runcorn, Ted Irving - a Day medalist - and of course Neil Opdyke, as well as to help this discipline mature, working with outstanding students, post-docs, and earth scientists of various stripes. The research has often involved fieldwork in exotic places and the use of nifty instruments such as the superconducting rock magnetometer in trying to understand phenomena on dimensional scales from sub-microscopic magnetic domains to the 6000-kilometer-wide core dynamo, and on temporal scales from the decadal fibrillations of secular variation, the many-million-year-long stochastic parade of polarity reversals, to the stately drift of the wandering continents, sometimes all in one study.

My introduction to the subject came at Lamont under the tutelage of Neil Opdyke in the late 1960's and early 1970's. Plate tectonics was in full swing - actually, a done-deal in many respects - but there were still lots of ideas to pursue, opportunities to go to sea, and plenty of stockpiled data, making the place a veritable candy store of research opportunities. I also met and married Carolyn in those years, got some papers published, and with an eventual PhD in hand, was hooked on making research a career.

I stayed at Lamont for another 25 years, largely with the beneficence of grants from the National Science Foundation. I had a succession of wonderful and productive graduate students who made me look good. There was Lisa Tauxe, who I would like to congratulate as this year's Woollard awardee, Dann Spariousu who worked on Appalachian tectonics, Brad Clement on polarity transitions, John Miller on Paleozoic remagnetizations, David Schneider on the dipole hypothesis, Bill Witte on the Triassic, Mickey Van Fossen on true polar wander, Vic DiVenere on Antarctica, and others, such as John Flynn and Anne Grunow, who worked in the lab as part of their thesis research.

I was also very fortunate to receive one of the first Doherty positions, a term appointment providing a level of institutional support that gave me the freedom to expand my research horizons beyond bootlegging off grants. Another source of deep satisfaction has been working with Paul Olsen on NSF-sponsored scientific drilling in the Newark basin and related projects in other Mesozoic rift basin in eastern North America, Greenland and Morocco.

I have been on the faculty at Rutgers for the past five years. This tenure has opened up new research directions for me, such as the Biocomplexity initiative with Paul Falkowski and Ken Miller and work on abrupt events in the early Cenozoic with Ben Cramer. I still maintain strong ties with Lamont so I have plenty of time to listen to Joni Mitchell and Velvet Underground while commuting on the New Jersey Turnpike.

Finally, I would like to acknowledge some additional colleagues and friends of long-standing who have influenced my work: Bill Lowrie for the value of quantification, Steve Cande for how to read the message from magnetic anomalies, Bill Berggren and Marie-Pierre Aubry for a more philosophical appreciation of stratigraphy, time and life, and of course Carolyn and our daughter, Amanda, for their support, interest, and patience. There are others as well, who I hope will forgive my omissions in these brief remarks.

Dear colleagues and friends, I am inspired by this honor. Thank you for being here to share it with me.