During three months in 1997 Dr. Griscom was a Fulbright-García Robles Fellow at
Universidad Nacional Autónoma de México in Mexico City, where he chose to initiate ESR
studies of debris from the bolide impact 65 million years ago that created the 180-km-
diameter Chicxulub crater buried 1 km beneath México’s Yucatán peninsula (discovered by
others in the early 1990’s and now nearly universally believed to mark the event responsible
for the extinction of the dinosaurs). In 2001 Griscom extended his studies of these materials
while Professeur Invité at Laboratoire Minéralogie–Cristallographie de Paris at Université de
Paris 6, Paris, France. The culmination of this research was a 41-page chapter by Griscom,
V. Beltrán-López, K. Pope, and A. Ocampo in the 3rd volume (2003) of the Springer
monograph series, Impact Studies.
Universidad Nacional Autónoma de México in Mexico City, where he chose to initiate ESR
studies of debris from the bolide impact 65 million years ago that created the 180-km-
diameter Chicxulub crater buried 1 km beneath México’s Yucatán peninsula (discovered by
others in the early 1990’s and now nearly universally believed to mark the event responsible
for the extinction of the dinosaurs). In 2001 Griscom extended his studies of these materials
while Professeur Invité at Laboratoire Minéralogie–Cristallographie de Paris at Université de
Paris 6, Paris, France. The culmination of this research was a 41-page chapter by Griscom,
V. Beltrán-López, K. Pope, and A. Ocampo in the 3rd volume (2003) of the Springer
monograph series, Impact Studies.
Using mostly the technique of electron spin resonance (ESR) spectrometry, Griscom was
responsible for the discovery and/or extensive characterization of nearly all known intrinsic
and extrinsic point defects in pure silica and heavy-metal fluoride glasses, as well as
experimental and theoretical advances in characterizing fine-grained ferromagnetic
precipitates in glasses. His principal research interest since 1973 has been radiation-
induced point defects in amorphous silica (a-SiO2). His studies of radiation-induced atomic
hydrogen in a-SiO2 with H2O impurities led him in 1986 to propose the now-universally-
accepted “hydrogen” model for the buildup of radiation-induced interface states in metal-
oxide-semiconductor (MOS) structures used for computer chips. This activity in turn
catalyzed Griscom’s subsequent discovery and characterization of self-trapped holes
(STHs) in silica.
From 1993 through 1996, his research centered on radiation hardening of pure-silica-core
optical fibers for monitoring fusion-reactor plasmas, while from 1996 to 1999 he was
Principal Investigator on a Department-of-Energy-sponsored program to investigate
possible radiation-induced decomposition of candidate glasses for nuclear waste disposal.
In recent months he reanalyzed his 1999 data for a unique 17-year-old simulated plutonium-
immobilization glass containing the highly radioactive isotope Pu-238 and presented these
results as an invited paper at the symposioum "SiO2, Advanced Dielectrics and Related
Devices", held in Saint-Etienne, France.
In 2000 he devised fractal-kinetics formalisms that he used to analyze the production and
thermal decay of radiation-induced defect centers in both pure and germanium-doped silica-
core optical fibers, discovering in the process some remarkable empirical rules for the
dependencies of the rate constants on dose rate.
responsible for the discovery and/or extensive characterization of nearly all known intrinsic
and extrinsic point defects in pure silica and heavy-metal fluoride glasses, as well as
experimental and theoretical advances in characterizing fine-grained ferromagnetic
precipitates in glasses. His principal research interest since 1973 has been radiation-
induced point defects in amorphous silica (a-SiO2). His studies of radiation-induced atomic
hydrogen in a-SiO2 with H2O impurities led him in 1986 to propose the now-universally-
accepted “hydrogen” model for the buildup of radiation-induced interface states in metal-
oxide-semiconductor (MOS) structures used for computer chips. This activity in turn
catalyzed Griscom’s subsequent discovery and characterization of self-trapped holes
(STHs) in silica.
From 1993 through 1996, his research centered on radiation hardening of pure-silica-core
optical fibers for monitoring fusion-reactor plasmas, while from 1996 to 1999 he was
Principal Investigator on a Department-of-Energy-sponsored program to investigate
possible radiation-induced decomposition of candidate glasses for nuclear waste disposal.
In recent months he reanalyzed his 1999 data for a unique 17-year-old simulated plutonium-
immobilization glass containing the highly radioactive isotope Pu-238 and presented these
results as an invited paper at the symposioum "SiO2, Advanced Dielectrics and Related
Devices", held in Saint-Etienne, France.
In 2000 he devised fractal-kinetics formalisms that he used to analyze the production and
thermal decay of radiation-induced defect centers in both pure and germanium-doped silica-
core optical fibers, discovering in the process some remarkable empirical rules for the
dependencies of the rate constants on dose rate.
David L. Griscom Ph.D. is a Research Physicist, retired in 2001 from Naval Research
Laboratory (NRL) in Washington, DC, after 33 years service, including 3 years as half-time
Program Manager at the Defense Advanced Research Projects Agency in Arlington, VA. He
is a Fellow of the American Physical Society, the American Association for the Advancement
of Science, and the American Ceramic Society, and a Fulbright-García Robles Fellow at
Universidad Nacional Autónoma de México in Mexico City in 1997. Between 2000 and 2004,
Griscom held visiting professorships of research at the Universities of Paris-6&7, Lyon-1,
and Saint-Etienne, France, and Tokyo Institute of Technology. He was Adjunct Professor of
Materials Science and Engineering at the University of Arizona from 2004 to 2005. The
winner of the 1993 N.F. Mott Award sponsored by the Journal of Non-Crystalline Solids, the
1995 Otto Schott Award offered by the Carl-Zeiss-Stiftung (Germany), a 1996 Outstanding
Graduate School Alumnus Award at Brown University, and the 1997 Sigma Xi Pure Science
Award at NRL, Griscom is principal author of 109 of his 187 published works, a body which
is highly cited by his peers according to his score (h=39) on the recently devised
Laboratory (NRL) in Washington, DC, after 33 years service, including 3 years as half-time
Program Manager at the Defense Advanced Research Projects Agency in Arlington, VA. He
is a Fellow of the American Physical Society, the American Association for the Advancement
of Science, and the American Ceramic Society, and a Fulbright-García Robles Fellow at
Universidad Nacional Autónoma de México in Mexico City in 1997. Between 2000 and 2004,
Griscom held visiting professorships of research at the Universities of Paris-6&7, Lyon-1,
and Saint-Etienne, France, and Tokyo Institute of Technology. He was Adjunct Professor of
Materials Science and Engineering at the University of Arizona from 2004 to 2005. The
winner of the 1993 N.F. Mott Award sponsored by the Journal of Non-Crystalline Solids, the
1995 Otto Schott Award offered by the Carl-Zeiss-Stiftung (Germany), a 1996 Outstanding
Graduate School Alumnus Award at Brown University, and the 1997 Sigma Xi Pure Science
Award at NRL, Griscom is principal author of 109 of his 187 published works, a body which
is highly cited by his peers according to his score (h=39) on the recently devised
Career Overview
| David L. Griscom, Ph.D. Physicist, Consultant |
Long-Term Research Specializations and Accomplishments
Recent Forays into Impact Geology
| Footnotes to photos at top. (2000) Dave Griscom and Pavle Premovic (Director, Laboratory for Geochemistry, Cosmochemistry & Astrochemistry, University of Nis, Serbia) with ESR spectrometer at Universite de Paris-6. (2001) Dave at Planetary Society expedition to Chicxulub crater ejecta outcrops, Albion Island, Belize. (2002) Dave in practice jersey of Mandai Memorials Hockey Club, Tokyo. (2007) Dave at GSA Penrose Conference on The Late Eocene Earth, Parc del Conero, Italy |
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In August 2003, Griscom and eight colleagues from labs in the U.S., France, and Japan
published in the proceedings of the international conference “Natural Glasses-4” an
unprecedentedly thorough materials-science characterization of the iron-oxide-welded
quartzite pebbles and cobbles of “upland deposits” of eastern Virginia, southern Maryland,
and Washington, DC, concluding that these rocks have no other interpretation than as being
ejecta from the 35.5-million-year-old, 90-km-diameter Chesapeake Bay crater (discovered
by scientists at the U.S. Geological Survey in the early 1990’s). Griscom presented his
purely geological evidence for the same conclusion at the 2007 Geological Society of
America Penrose Conference on The Late Eocene Earth, held in Monte Cònero, Italy. Due to
what he regards as an unjustified rejection the manuscript he submitted for the proceedings
of this conference, he has opted to web-publish it here.
published in the proceedings of the international conference “Natural Glasses-4” an
unprecedentedly thorough materials-science characterization of the iron-oxide-welded
quartzite pebbles and cobbles of “upland deposits” of eastern Virginia, southern Maryland,
and Washington, DC, concluding that these rocks have no other interpretation than as being
ejecta from the 35.5-million-year-old, 90-km-diameter Chesapeake Bay crater (discovered
by scientists at the U.S. Geological Survey in the early 1990’s). Griscom presented his
purely geological evidence for the same conclusion at the 2007 Geological Society of
America Penrose Conference on The Late Eocene Earth, held in Monte Cònero, Italy. Due to
what he regards as an unjustified rejection the manuscript he submitted for the proceedings
of this conference, he has opted to web-publish it here.
Paris, 2000 Belize, 2001 Tokyo, 2002 Italy, 2007