Brian Marshall is a Scientist Emeritus with the Geology, Geophysics, and Geochemistry Science Center.
Professional Experience
USGS Yucca Mountain Project Branch, Geochemistry Team Chief (2007-2010): Leader of team of geochemists and hydrologists responsible for defining, executing, and reporting on research for a variety of projects both externally and internally funded.
USGS Yucca Mountain Project Branch, Research Hydrologist/Geologist (1999-2007): Chemical and isotopic composition of pore water, rocks and secondary minerals in a thick vadose zone that is the proposed site of a nuclear waste repository. Responsible for formulating the research tasks, writing operating procedures, and publishing results, often with colleagues working on the same project.
Abstracts and Presentations
Marshall, B.D. and Futa, K., 2003, Strontium in pore water from the Topopah Spring Tuff, Yucca Mountain, Nevada. Proceedings of the Tenth International High-Level Radioactive Waste Management Conference, Las Vegas, NV. American Nuclear Society, La Grange Park, IL, p. 373-376.
Marshall, B.D., Stuckless, J.S., Peterman, Z.E., and Whelan, J.F., 1993, Isotopic studies of cavity filling and fracture coating minerals as an aid to understanding paleohydrology, Yucca Mountain, Nevada, USA, in Paleohydrological Methods and their Applications, Proceedings of NEA-OECD Workshop held November 1992, p. 147.
Science and Products
From Outcrop to Ions: development and application of in-situ isotope ratio measurements to solve geologic problems
Fluid geochemistry of Yucca Mountain and vicinity
Limited hydrologic response to Pleistocene climate change in deep vadose zones - Yucca Mountain, Nevada
Feldspar dissolution rates in the Topopah Spring Tuff, Yucca Mountain, Nevada
Origin and paleoclimatic significance of late Quaternary loess in Nebraska: Evidence from stratigraphy, chronology, sedimentology, and geochemistry
Thermal history of the unsaturated zone at Yucca Mountain, Nevada, USA
Strontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada, and Inyo County, California
Chemistry of water collected from an unventilated drift, Yucca Mountain, Nevada
Evidence for ground-water stratification near Yucca Mountain, Nevada
Field investigation of the drift shadow
Reply to “Commentary: Assessment of past infiltration fluxes through Yucca Mountain on the basis of the secondary mineral record—Is it a viable methodology?” by Y.V. Dublyansky and S.Z. Smirnov
Geochemical and C, O, Sr, and U-series isotopic evidence for the meteoric origin of calcrete at Solitario Wash, Crater Flat, Nevada, USA
Reply to the comment on “Physical and stable-isotope evidence for formation of secondary calcite and silica in the unsaturated zone, Yucca Mountain, Nevada”, by Y.V. Dublyansky, S.E. Smirnov and G.P. Palyanova
Non-USGS Publications**
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**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
From Outcrop to Ions: development and application of in-situ isotope ratio measurements to solve geologic problems
Project objectives are to (1) develop innovative analytical techniques for isotope geochemistry and U-Pb geochronology using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and (2) apply these techniques to collaborative research projects of high priority to the Mineral Resources Program, including studies related to the formation of "critical mineral" deposits, and... - Publications
Filter Total Items: 44
Fluid geochemistry of Yucca Mountain and vicinity
Yucca Mountain, a site in southwest Nevada, has been proposed for a deep underground radioactive waste repository. An extensive database of geochemical and isotopic characteristics has been established for pore waters and gases from the unsaturated zone, perched water, and saturated zone waters in the Yucca Mountain area. The development of this database has been driven by diverse needs of the YucAuthorsBrian D. Marshall, Richard J. Moscati, Gary L. PattersonLimited hydrologic response to Pleistocene climate change in deep vadose zones - Yucca Mountain, Nevada
Understanding the movement of water through thick vadose zones, especially on time scales encompassing long-term climate change, is increasingly important as societies utilize semi-arid environments for both water resources and sites viewed as favorable for long-term disposal or storage of hazardous waste. Hydrologic responses to Pleistocene climate change within a deep vadose zone in the easternAuthorsJ.B. Paces, L.A. Neymark, J. F. Whelan, J. L. Wooden, S.P. Lund, B.D. MarshallFeldspar dissolution rates in the Topopah Spring Tuff, Yucca Mountain, Nevada
Two different field-based methods are used here to calculate feldspar dissolution rates in the Topopah Spring Tuff, the host rock for the proposed nuclear waste repository at Yucca Mountain, Nevada. The center of the tuff is a high silica rhyolite, consisting largely of alkali feldspar (∼60 wt%) and quartz polymorphs (∼35 wt%) that formed by devitrification of rhyolitic glass as the tuff cooled. FAuthorsC.R. Bryan, K.B. Helean, B.D. Marshall, P.V. BradyOrigin and paleoclimatic significance of late Quaternary loess in Nebraska: Evidence from stratigraphy, chronology, sedimentology, and geochemistry
Loess is one of the most extensive surficial geologic deposits in midcontinental North America, particularly in the central Great Plains region of Nebraska. Last-glacial-age loess (Peoria Loess) reaches its greatest known thickness in the world in this area. New stratigraphic, geochronologic, mineralogic, and geochemical data yield information about the age and provenance of Peoria Loess, as wellAuthorsDaniel R. Muhs, E. Arthur Bettis, John N. Aleinikoff, John P. McGeehin, Jossh Beann, Gary Skipp, Brian D. Marshall, Helen M. Roberts, William C. Johnson, Rachel BentonThermal history of the unsaturated zone at Yucca Mountain, Nevada, USA
Secondary calcite, silica and minor amounts of fluorite deposited in fractures and cavities record the chemistry, temperatures, and timing of past fluid movement in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a high-level radioactive waste repository. The distribution and geochemistry of these deposits are consistent with low-temperature precipitation from meteoric watersAuthorsJ. F. Whelan, L.A. Neymark, R.J. Moscati, B.D. Marshall, E. RoedderStrontium Isotopic Composition of Paleozoic Carbonate Rocks in the Nevada Test Site Vicinity, Clark, Lincoln, and Nye Counties, Nevada, and Inyo County, California
Ground water moving through permeable Paleozoic carbonate rocks represents the most likely pathway for migration of radioactive contaminants from nuclear weapons testing at the Nevada Test Site, Nye County, Nevada. The strontium isotopic composition (87Sr/86Sr) of ground water offers a useful means of testing hydrochemical models of regional flow involving advection and reaction. However, reactionAuthorsJames B. Paces, Zell E. Peterman, Kiyoto Futo, Thomas A. Oliver, Brian D. MarshallChemistry of water collected from an unventilated drift, Yucca Mountain, Nevada
Water samples (referred to as puddle water samples) were collected from the surfaces of a conveyor belt and plastic sheeting in the unventilated portion of the Enhanced Characterization of the Repository Block (ECRB) Cross Drift in 2003 and 2005 at Yucca Mountain, Nevada. The chemistry of these puddle water samples is very different than that of pore water samples from borehole cores in the same rAuthorsB.D. Marshall, T.A. Oliver, Z. E. PetermanEvidence for ground-water stratification near Yucca Mountain, Nevada
Major- and trace-element concentrations and strontium isotope ratios (strontium-87/strontium-86) in samples of ground water potentially can be useful in delineating flow paths in the complex ground-water system in the vicinity of Yucca Mountain, Nevada. Water samples were collected from boreholes to characterize the lateral and vertical variability in the composition of water in the saturated zoneAuthorsK. Futa, B.D. Marshall, Z. E. PetermanField investigation of the drift shadow
The "Drift Shadow" is defined as the relatively drier region that forms below subsurface cavities or drifts in unsaturated rock. Its existence has been predicted through analytical and numerical models of unsaturated flow. However, these theoretical predictions have not been demonstrated empirically to date. In this project we plan to test the drift shadow concept through field investigations andAuthorsG.W. Su, T.J. Kneafsey, T.A. Ghezzehei, P.J. Cook, B.D. MarshallReply to “Commentary: Assessment of past infiltration fluxes through Yucca Mountain on the basis of the secondary mineral record—Is it a viable methodology?” by Y.V. Dublyansky and S.Z. Smirnov
Many of the comments by Dublyansky and Smirnov (2005) on Marshall et al. (2003) reflect a longstanding debate over the origin of secondary calcite and opal deposits found in cavities and on fracture surfaces at Yucca Mountain, Nevada, site of a proposed high-level nuclear waste repository (US Department of Energy, 2001). These comments require consideration of data and interpretations beyond the sAuthorsBrian D. Marshall, Leonid A. Neymark, Zell E. PetermanGeochemical and C, O, Sr, and U-series isotopic evidence for the meteoric origin of calcrete at Solitario Wash, Crater Flat, Nevada, USA
Calcite-rich soils (calcrete) in alluvium and colluvium at Solitario Wash, Crater Flat, Nevada, USA, contain pedogenic calcite and opaline silica similar to soils present elsewhere in the semi-arid southwestern United States. Nevertheless, a ground-water discharge origin for the Solitario Wash soil deposits was proposed in a series of publications proposing elevation-dependent variations of carbonAuthorsL.A. Neymark, J.B. Paces, B.D. Marshall, Z. E. Peterman, J. F. WhelanReply to the comment on “Physical and stable-isotope evidence for formation of secondary calcite and silica in the unsaturated zone, Yucca Mountain, Nevada”, by Y.V. Dublyansky, S.E. Smirnov and G.P. Palyanova
No abstract available.AuthorsJoseph F. Whelan, James B. Paces, Zell E. Peterman, Brian D. Marshall, Leonid A. NeymarkNon-USGS Publications**
Marshall, Brian D. and DePaolo, Donald J., 1989, Calcium isotopes in igneous rocks and the origin of granite: Geochimica et Cosmochimica Acta, v. 53, p. 917-922, https://doi.org/10.1016/0016-7037(89)90036-7.Marshall, B.D., Woodard, H.H., and DePaolo, D.J., 1986, K-Ca-Ar systematics of authigenic sanidine from Waukau, Wisconsin, and the diffusivity of argon: Geology, v. 14, p. 936-938, https://doi.org/10.1130/0091-7613(1986)14<936:KSOASF>2.0.CO;2.
.Marshall, B.D. and DePaolo, D.J., 1982, Precise age determinations and petrogenetic studies using the K-Ca method: Geochimica et Cosmochimica Acta, v.46, p. 2537-2545, https://doi.org/10.1016/0016-7037(82)90376-3.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.