David E. Broxton

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 Geology and Geochemistry Group, EES-1, MS D462Los Alamos National Laboratory, Los Alamos, NM 87545

Phone: 505-667-2492

e-mail: broxton@lanl.gov

 

Education:

Received Amoco Scholarship for academic achievement, University of North Carolina, 1973-74

Recipient of Los Alamos Achievement Award from Environment and Surveillance Division at Laboratory for contributions to Hydrogeologic Workplan, 1996

Professional Experience:
1994-present Technical team leader for the Canyons Focus Area for the Environmental Restoration Program. Provide technical direction and oversight to Canyons investigations; integrate technical data across numerous disciplines; lead efforts to establish an effective technical approach for ER investigations in canyon settings. Assign work and monitor the performance of other technical team members for the focus area. Plan and track cost and schedules for Canyons activities. Coordinate, plan, and direct the drilling activities for the implementation of the Hydrogeologic Workplan, working closely with funding programs (ER and DP), DOE, the Groundwater Integration Team, groundwater modelers, other participants, regulators, and stakeholders. Contribute to the preparation and submittal of administrative authority (NMED) documents, including RCRA RFI work plans and RFI reports. Prepare, implement, and review of work releases for subcontractor work; assist in the preparation of task order proposals; and monitor budget, schedule, and work products of subcontractors. Provide leadership for strategic planning, including the evaluation of technical and regulatory options.

 
1981-present Geologist participating in mineralogic, petrologic and chemical studies of diagenetic minerals in pyroclastic rocks at a potential underground high-level nuclear waste repository in southern Nevada for the Yucca Mountain Project. Conducted petrographic and chemical investigations of secondary minerals in tuffs to improve subsurface extrapolation of alteration zones that are important natural barriers to radionuclide migration from the potential repository. Technical Coordinator of multidisciplinary team of earth scientists conducting Mineralogy-Petrology investigations from 1988-1992. Currently providing geologic and mineralogic support for siting and implementing unsaturated hydrologic field test at Busted Butte in support of the license application for the potential repository at Yucca Mountain.

 
1992-1994 Principal Investigator for Geology conducting stratigraphic, mineralogic, and geochemical studies of rock units on the Pajarito Plateau for the Earth Science Council of the Environmental Restoration Project. Conducted stratigraphic studies of Bandelier Tuff and Cerro Toledo deposits to define vertical and lateral changes in rock properties that influence groundwater migration through these tuffs. Also, performed geochemical investigations to define the background geochemistry of bedrock units for the Environmental Restoration Project. Served as chairman of the Earth Science Council from 1995 to 1997.

 
1983-1993 Co-investigator of research project "Petrologic study of the chemical evolution of silicic volcanic rocks erupted from the Timber Mountain-Oasis Valley caldera complex, southern Nevada". This project was initiated as a LANL-sponsored basic research project and was later supported by the Yucca Mountain Project and Containment Program. This research project examined the chemical evolution of magmas erupted over a 7 million year period at a multicycle caldera complex. The work involved field studies to collect representative samples of the volcanic rock units, chemical and petrographic studies to define mineralogic and geochemical trends with time, and isotopic and geochronology studies to define magma sources and ages. Collaborators included investigators from the University of Colorado, Boulder and the US Geological Survey.

 
1983-1985 Geologist participating in geochemical exploration for precious-and base-metal deposits in St. Lucia in Costa Rica for U.S. AID. Supported design and planning for geochemical survey and provided training to field crews. Led field teams and participated in sampling efforts in remote areas of both countries. Contributed to data interpretation and documentation of sampling program.

 
1982-1984 Associate Group Leader for Geology/Geochemistry Group. Provided line and program management support to group leader for a diverse group of earth scientists involved in variety of programs including disposal of high-level nuclear waste, hot dry rock energy extraction, mineral resource assessments, and basic research.

 
1979-1982 Assistant Group Leader for Resource Characterization Group. Provided line and program management support to group leader for a multidisciplinary group whose mission was to identify strategic mineral resources for the nation.

 
1977-1981 Geologist participating in geochemical exploration for mineral resources in Alaska and the Rocky Mountains region as part of the National Uranium Exploration Program; Responsible for the design, implementation, interpretation, and documentation of a multielement geochemical survey of stream sediments, stream waters, springs, and well waters in Montana and parts of Idaho and Colorado. Participated in geochemical surveys in the Panhandle, Yukon, and Brooks Range areas of Alaska. Participated in the development of a geochemical atlas for Alaska; Was program manager for this geochemical exploration program during its final two years.

1974, Summer. Geologist, Atlantic Richfield Company, Denver, CO. Field team leader for stratabound uranium exploration in the Laramie Range, Owl Creek Mountains, Casper Range of Wyoming. Led drilling program to test for the occurrence and extent of stratabound uranium deposits in leases.

1974-1975, Teaching Assistant at the University of New Mexico. Taught undergraduate lab for introductory geology and was teaching assistant for petrography, igneous petrology, field geology, and advanced field geology courses.

Select Publications:

Broxton, D. E., Gilkeson, R., Longmire, P., Marin, J., Warren, R., Crowder, A., Newman, B., Lowry, B., Daymon, D., and Wycoff, D., 1998, Interim Completion Report for Characterization Well R-9, Los Alamos National Laboratory Report LA-UR-98-3569, 74 p.

Broxton, D. E., Warren, R., Crowder, A., Everett, M., Gilkeson, R., Longmire, P., Marin, J., 1998, Interim Completion Report for Characterization Well R-12, Los Alamos National Laboratory Report LA-UR-98-3976, 56 p.

Reneau, S. L., Broxton, D. E., Carney, J. S., and LaDelfe, C., 1998 Structure of the Tshirege Member of the Bandelier Tuff at Mesita del Buey, Technical Area 54, Los Alamos National Laboratory: Los Alamos National Laboratory Report LA-13538-MS, 16 p.

Ryti, R. T., Longmire, P. A., Broxton, D. E., Reneau, S. L., and McDonald, E. V., 1998, Inorganic and Radionuclide Background Data for Soils, Sediments and Bandelier Tuff at Los Alamos National Laboratory: Los Alamos National Laboratory report LA-UR-98-4847.

Broxton, D. E., Ryti, R. T., and Reneau, S. L., 1997, Natural background geochemistry of the Bandelier Tuff and other rock units, Los Alamos, New Mexico: Geological Society of America Abstracts With Programs, v. 29. no. 6, p. A-434.

Broxton, D. E., and Reneau, S. L., 1996, Buried early Pleistocene landscapes beneath the Pajarito Plateau, northern New Mexico, in The Jemez Mountains region: New Mexico Geological Society Forty-Seventh Annual Field Conference Guidebook, p. 325-334.

Broxton, D.E., Vaniman, D., Chipera, S.J., Kluk, E.C., and Warren, R.G., 1996, Stratigraphy, mineralogy and chemistry of tuffs at Pajarito Mesa, in Reneau, S. L., and Raymond, R., Jr., editors, Geological Site Characterization For the Proposed Mixed Waste Disposal Facility, Los Alamos National Laboratory: Los Alamos National Laboratory Report LA-13089-MS, Los Alamos, New Mexico, pp. 5-30.

Stimac, J.A., Hickmott, D., Abell, R., Larocque, A., Broxton, D.E., Gardner, J., and Chipera, S.J., 1996, Redistribution of Pb and other volatile trace metals during eruption, devitrification, and vapor-phase crystallization of the Bandelier Tuff, New Mexico, J. Volcanol. Geotherm. Research, 73, pp.245-266.

Broxton, D.E., Ryti, R.T., Reneau, S.L., Duffy, C., and Longmire, P., 1996, Natural background geochemistry of the Bandelier Tuff and other rock units, in Longmire, P.A., Broxton, D.E., and Reneau, S.L., editors, Natural Background Geochemistry and Statistical Analysis of Selected Soil Profiles, Sediments, and Bandelier Tuff, Los Alamos, New Mexico, Los Alamos National Laboratory Report LAUR-95-3468, 82p.

Broxton, D. E., Ryti, R. T., Carlson, D., Warren, R.G., Kluk, E., and Chipera, S., 1996, Natural background geochemistry of the Bandelier Tuff at MDA P, Los Alamos National Laboratory: Los Alamos National Laboratory Report LAUR-96-1151, 42p.

WoldeGabriel, G., Broxton, D. E., and Byers, F. M., Jr, 1996, Mineral and temporal relations of coexisting authigenic minerals in altered tuffs and the utility of alkali zeolites as potential low-temperature datable minerals, Jour. Volcanology Geotherm. Res., 71, pp. 155-165.

Broxton, D. E. and Eller, P.G., 1995, editors, Earth Science Investigations for Environmental Restoration—Los Alamos National Laboratory Technical Area 21, Los Alamos National Laboratory Report LA-12934-MS, 118p.

Broxton, D.E., Heiken, G., Chipera, S.J., and Byers, F.M., Jr., 1995, Stratigraphy, Petrography, and Mineralogy of Bandelier Tuff and Cerro Toledo deposits, in D.E.Broxton and P.G. Eller, eds., Earth Science Investigations for Environmental Restoration—Los Alamos National Laboratory Technical Area 21, Los Alamos National Laboratory Report LA-12934-MS pp. 33-64.

Broxton, D.E., Longmire, P.A., Eller, P.G., and Flores, D., 1995, Preliminary drilling results for boreholes LADP-3 and LADP-4 in D.E.Broxton and P.G. Eller, eds., Earth Science Investigations for Environmental Restoration—Los Alamos National Laboratory Technical Area 21, Los Alamos National Laboratory Report LA-12934-MS pp. 93-110.

Broxton, D.E. and Reneau, S.L., 1995 Stratigraphic nomenclature of the Bandelier Tuff for the Environmental Restoration project at Los Alamos National Laboratory, Los Alamos National Laboratory Report LA-13010-MS, 21p.

Broxton, D. E., Byers, F. M., Jr., and Chipera, S. J., 1993, Geologic evaluation of six nonwelded tuff sites in the vicinity of Yucca Mountain, Nevada for a surface-based test facility for the Yucca Mountain Project, Los Alamos National Lab. Report LA-12542 MS, 83 pp.

Broxton, D. E., 1992, Chemical changes associated with zeolitization of the tuffaceous beds of Calico Hills, Yucca Mountain, Nevada, in Y. K. Kharaka and A. S. Maest, eds,Water-Rock Interaction, Proceedings of the 7th International Symposium on Water-Rock Interaction, WRI-7, Park City, Utah, A. A. Balkema, Rotterdam, pp. 699-703.

Farmer, G. L., Broxton, D. E., Warren, R. G., and Pickthorn, W., 1991, Nd, Sr, and O isotopic variations in metaluminous ash-flow tuffs and related volcanic rocks at the Timber Mountain-Oasis Valley Caldera Complex, SW Nevada: Implications for the origin and evolution of large-volume silicic magma bodies, Contrib. Mineral. Petrol., pp. 53-68.

Broxton, D. E., Warren, R. G., Byers, F. M., Jr., Scott, R. B., 1989, Chemical and mineralogic trends within the Timber-Mountain-Oasis Valley caldera complex, Nevada: Evidence for multiple cycles of chemical evolution in a long-lived silica magma system, Jour. Geophys. Res., v. 94, No. B5, pp. 5961-5985.

Warren, R. G., Byers, F. M., Jr., Broxton, D. E., Freeman, S. H., and Hagan, R. C., 1989, Magmatic environment of the large volume ash-flow sheets of the southwestern Nevada volcanic field, as deduced from phenocrysts contents and compositions, Jour. Geophys. Res., v. 94, No. B5, pp. 5987-6020.

Broxton, D. E., Byers, F. M., Jr., and Warren, R. G., 1988, Petrography and phenocryst chemistry of volcanic units at Yucca Mountain, Nevada: a comparison of outcrop and drill hole samples, Los Alamos National Lab. Report LA-11503-MS, 65 p.

Broxton, D. E., 1987, Clinoptilolite compositions in diagenetically-altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada, The Technology of High-Level Nuclear Waste Disposal, P. L. Hofmann, Ed., Battelle Mem. Institute, Columbus, OH, v. 3, pp. 179-194.

Broxton, D. E., Bish, D. L., and Warren, R. G., 1987, Distribution and chemistry of diagenetic minerals, Yucca Mountian, Nye Country, Nevada, Clays and Clay Minerals, v. 35, pp. 89-110.

Broxton, D. E., Warren, R. G., Hagan, R. C., and Luedemann, G., 1986, Chemistry of diagenetically altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada, Los Alamos National Lab. Report LA-10802- MS, 160 pp.

Kudo, A. M., and Broxton, D. E., 1985, High-potassium rocks of the Crandall ring-dike complex, Absaroka Mountains, Wyoming, Geol. Soc. America Bull., v. 96, pp. 522-528.

Weaver, T. A., Freeman, S. H., Broxton, D. E., and Bolivar, S. L., 1983, The Geochemical Atlas of Alaska, Los Alamos National Lab. Report LA-9897-MS, GJBX-32(83), 57 p.