Cameron M. Mercer, Ph.D.
Cameron Mercer is a Mendenhall postdoctoral fellow working in the Denver Argon Geochronology Laboratory at the Geology, Geophysics, and Geochemistry Science Center.
I joined the Denver Argon Geochronology Laboratory at the USGS Geology, Geophysics, and Geochemistry Science Center as a Mendenhall postdoctoral fellow in 2020. I was previously a postdoc in the Mid-Atlantic Noble Gas Research Laboratory at NASA Goddard Space Flight Center. I received my PhD from the School of Earth and Space Exploration at Arizona State University in 2017, and a BA in Geology and Physics from Middlebury College in 2011.
My previous research mostly focused on high spatial resolution and incremental heating 40Ar/39Ar geochronology of lunar impact melt rocks. I also performed thermal-kinematic numerical modeling to assess Ar loss due to the formation of melt veins in polymict impact breccias, and I developed a software tool to promote more robust reuse of previously published K-Ar and 40Ar/39Ar datasets. My current research focuses on 40Ar/39Ar geochronology of igneous rocks and alteration minerals associated with a variety of critical mineral deposits in the U.S.
Professional Experience
2020-present, Research Geologist/Mendenhall Postdoctoral Fellow, U.S. Geological Survey
2019-2020, Postdoctoral Fellow, CRESST II/Catholic University of America (CUA)/NASA Goddard Space Flight Center (GSFC) Code 698
2017-2019, Postdoctoral Research Associate, School of Earth and Space Exploration, Arizona State University
Education and Certifications
Ph.D. Geology, School of Earth and Space Exploration, Arizona State University, 2017
B.A. Geology and Physics, Middlebury College, 2011
Honors and Awards
2016, Stephen E. Dwornik Planetary Geoscience Student Paper Award (best graduate poster, 47th Lunar and Planetary Science Conference)
2012, Eugene M. Shoemaker Impact Cratering Award
2011, Charles G. Doll Award (best undergraduate presentation, Vermont Geological Society Spring Meeting)
2010, Stephen E. Dwornik Planetary Geoscience Student Paper Award (best undergraduate poster, 41th Lunar and Planetary Science Conference)
Abstracts and Presentations
Mercer, C. M., A. Andersen, D. A. Olinger, P. L. Verplanck, M. A. Cosca, L. E. Morgan, 2022. Timing of Silicate and Carbonatite Magmatism Forming the Bear Lodge Alkaline Complex: New Insights from 40Ar/39Ar Geochronology. GSA Connects, 94-10. Geological Society of America Abstracts with Programs. Vol 54, No. 5, 2022 doi: 10.1130/abs/2022AM-381942.
Mercer, C. M., L. E. Morgan, M. A. Cosca, A. H. Hofstra, R. A. Ayuso, N. K. Foley, 2022. 40Ar/39Ar geochronology of volcanic rocks associated with Be mineralization in the Spor Mountain Formation, Utah, USA. Goldschmidt, 8hP4.
Mercer, C. M., K. V. Hodges, B. L. Jolliff, M. C. van Soest, C. S. McDonald, 2019. Reviewing the Geochronologic Constraints from Samples of Boulders at Apollo 17 Stations 2, 6, and 7: Implications for Understanding the Stratigraphy of the North and South Massiffs in the Valley of Taurus-Littrow. Lunar and Planetary Science Conference L, Abs. #3049.
Mercer, C. M., K. V. Hodges, B. L. Jolliff, M. C. van Soest, J.-A. Wartho, K. E. Young, and J. R. Weirich, 2018. Taking a Close Look at Dating Old Impact Melt Rocks: High Spatial Resolution 40Ar/39Ar Geochronology of Some Apollo 17 Samples. Lunar and Planetary Science Conference XLIX, Abs. #2528.
Schmitt, H. H., N. E. Petro, M. S. Robinson, R. A. Wells, C. M. Mercer, and B. P. Weiss, 2018. Apollo 17 Exploration of Taurus-Littrow: Summary of Major Findings. Lunar and Planetary Science Conference XLIX, Abs. #2961.
Mercer, C. M., and K. V. Hodges, 2017. Modeling the Diffusive Loss of Argon in Response to Melt Vein Formation in Polygenetic Impact Melt Breccias. Lunar and Planetary Science Conference XLVIII, Abs. #2224.
Mercer, C. M., and K. V. Hodges, 2016. ArAR — Software to Account for Discrepancies Between K/Ar and 40Ar/39Ar Datasets Published with Different Decay, Isotopic, and Monitor-Age Parameters. Geological Society of America Annual Meeting, Abs. #238-7.
Mercer, C. M., K. V. Hodges, and M. C. van Soest, 2016. Exploring Non-Uniform 40Ar* Loss in Apollo 16 Impact Melt Breccias Using a Laser Microprobe. Lunar and Planetary Science Conference XLVII, Abs. #2503.
Mercer, C. M., K. V. Hodges, M. C. van Soest, and C. S. McDonald, 2016. Exploring the Partial Loss of 40Ar* and Potential Recoil Effects in Two Apollo 16 Impact Melt Breccias: Comparison of Laser Microprobe and Incremental Heating 40Ar/39Ar Results. Geological Society of America Annual Meeting, Abs. #259-10.
Mercer, C. M., K. V. Hodges, 2016. ArAR—A Software Tool to Promote the Robust Comparison of K-Ar and 40Ar/39Ar Dates Published with Different Decay, Isotopic, and Monitor-Age Parameters. Lunar and Planetary Science Conference XLVII, Abs. #2302.
Mercer, C. M., K. V. Hodges, B. L. Jolliff, M. C. van Soest, J.-A. Wartho, and J. R. Weirich, 2015. High Spatial Resolution 40Ar/39Ar Geochronology of Impact Melt Breccias from Apollo 17 Boulders at Stations 2, 6, and 7. American Geophysical Union Fall Meeting, Poster P33C-2136.
Schmitt, H. H., N. E. Petro, M. S. Robinson, R. Wells, B. Weiss, and C. M. Mercer, 2015. Lunar Field Geological Interpretations Assisted by LROC, Mini-RF and M3: Taurus-Littrow. American Geophysical Union Fall Meeting, P43F-08.
Mercer, C. M., K. V. Hodges, B. L. Jolliff, M. C. van Soest, J.-A.Wartho, and J. R.Weirich, 2015. Spatially Resolved, Correlated Variations in Apparent 40Ar/39Ar Ages and Ca/K Ratios in Apollo 17 Impact Melt Breccia 77135. The First 1 Ga of Impact Records: Evidence from Lunar Samples and Meteorites, 78th Annual Meeting of the Meteoritical Society, Abs. #6018.
Mercer, C. M., A. K. Souders, S. J. Romaniello, C. D. Williams, G. A. Brennecka, M. Wadhwa, 2015. Chromium and Titanium Isotope Systematics of Allende CAIs. Lunar and Planetary Science Conference XLVI, Abs. #2920.
Mercer, C. M., and K. V. Hodges, 2014. Modeling Argon Isotopic Behavior in Polygenetic Impact Melt Breccias. American Geophysical Union Fall Meeting, Poster V41A-4770.
Mercer, C. M., K. E. Young, J. R. Weirich, K. V. Hodges, B. L. Jolliff, J.-A. Wartho, and M. C. van Soest, 2014. Over 500 million years of lunar impact history quantified by laser microprobe 40Ar/39Ar dating of two Apollo 17 breccias. Lunar and Small Bodies Graduate Conference, NASA Ames Research Center, Mountain View, CA.
Mercer, C. N., M. H. Reed, and C. M. Mercer, 2014. Timescales of Porphyry Cu Deposit Formation: Insights from Titanium Diffusion in Quartz. Goldschmidt, 12e.
Mercer, C. M., K. E. Young, J. R. Weirich, K. V. Hodges, B. L. Jolliff, J.-A. Wartho, and M. C. van Soest, 2014. Diverse Impact Histories of Apollo 17 Melt Breccias Revealed by In Situ 40Ar/39Ar Geochronology. Lunar and Planetary Science Conference XLV, Abs. #2669.
Mercer, C. M., D. A. Williams, J. E. Scully, D. T. Blewett, D. L. Buczkowski, R. Jaumann, P. M. Schenk, R. A. Yingst, W. B. Garry, T. Roatsch, F. Preusker, C. M. Pieters, C. T. Russell, C. A. Raymond, M. C. De Sanctis, and the Dawn Science Team, 2012. Geologic Mapping of the AV-5 Floronia Quadrangle of Asteroid 4 Vesta. Lunar and Planetary Science Conference XLIII, Abs. #1716.
Mercer, C. M., 2011. Petrogenesis of Two New Eucrites from Northwest Africa: Evidence From Petrography, Mineral Chemistry, and Bulk Chemistry. (Unpublished Senior Thesis, Middlebury College, Middlebury, Vermont.) Vermont Geological Society Spring Meeting.
Mercer, C. M., Jones, J. H., Draper, D. S., Usui, T., and Le, L. H., 2010. Experimental Evolution of Yamato 980459 via Equilibrium Crystallization at 0.5 GPa: Approaching Queen Alexandra Range 94201, Lunar and Planetary Institute 26th Annual Summer Intern Conference, Abs. #1006.
Mercer, C. M. and Cohen, B. A., 2010. Principal Components Analysis of Reflectance Spectra Returned by the Mars Exploration Rover Opportunity. Lunar and Planetary Science Conference XLI, Abs. #1377.
Mercer, C. M., 2009. Principal Components Analysis of Reflectance Spectra Returned by the Mars Exploration Rover Opportunity. NASA Marshall Space Flight Center Summer Intern Poster Expo.
Science and Products
Argon Geochronology
Geochemical analyses of rock samples collected from the Judith Mountains and Crazy Mountains alkalic complexes, Montana
Geochemical data include major, minor and trace element results for 42 alkaline silicate igneous rock samples. Samples were collected from natural exposures/outcrops during field work in the Central Montana Alkaline Province (CMAP) during the summer of 2022. All samples were analyzed by the U.S. Geological Survey contract laboratory, SGS Labs. Major, minor, and trace elements were determined via w
U-Pb detrital zircon data and Ar feldspar data from middle Cenozoic sandstones and volcanic tuffs from southern Nevada, USA
Argon and SHRIMP-RG Data for Magmatic Steam Alunite, Sericite, and Zircon from Alunite Ridge and Deer Trail Mountain, Marysvale, Utah
Using the potassium-argon laser experiment (KArLE) to date ancient, low-K chondritic meteorites
Paleogene sedimentary basin development in southern Nevada, USA
The Mount Weld rare earth element deposit, Western Australia: A carbonatite-derived laterite
Carbonatite-hosted rare earth element (REE) deposits are the primary source of the world’s light REEs and have the potential to be a source of heavy REEs. The Mount Weld REE deposit in Western Australia is hosted in a lateritic sequence that reflects supergene enrichment of the underlying carbonatite complex. Similar to other carbonatite-related ore deposits, ore from Mount Weld displays extreme l
40Ar/39Ar geochronology of magmatic-steam alunite from Alunite Ridge and Deer Trail Mountain, Marysvale Volcanic Field, Utah: Timing and duration of miocene hydrothermal activity associated with concealed intrusions
Interpreting and reporting 40Ar/39Ar geochronologic data
Time scales of porphyry Cu deposit formation: insights from titanium diffusion in quartz
Non-USGS Publications**
**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
Argon Geochronology
This project supports the USGS argon geochronology laboratory in Denver. The USGS 40Ar/39Ar geochronology laboratory is a state-of-the-art research facility for determining absolute ages of minerals and rocks. The 40Ar/39Ar laboratory contributes critical geochronology to individual USGS research projects and to partners in academia and other Federal agencies. This laboratory develops methodology... - Data
Geochemical analyses of rock samples collected from the Judith Mountains and Crazy Mountains alkalic complexes, Montana
Geochemical data include major, minor and trace element results for 42 alkaline silicate igneous rock samples. Samples were collected from natural exposures/outcrops during field work in the Central Montana Alkaline Province (CMAP) during the summer of 2022. All samples were analyzed by the U.S. Geological Survey contract laboratory, SGS Labs. Major, minor, and trace elements were determined via w
U-Pb detrital zircon data and Ar feldspar data from middle Cenozoic sandstones and volcanic tuffs from southern Nevada, USA
This Data Release accompanies the planned publication, "Paleogene sedimentary basin development in southern Nevada, USA." Included here are U-Pb detrital zircon and Ar/Ar feldspar geochronologic data for middle Cenozoic sedimentary and volcanic rocks collected by Jens-Erik Lundstern and Theresa M. Schwartz in several parts of southern Nevada, U.S. The target strata are the lowest Cenozoic sedimentArgon and SHRIMP-RG Data for Magmatic Steam Alunite, Sericite, and Zircon from Alunite Ridge and Deer Trail Mountain, Marysvale, Utah
Samples of vein-type magmatic-steam alunite were collected over several field seasons from five mines and prospects (L&N, Mt. Edna, Christmas, upper Mineral Products, and Close In) in the Alunite Ridge and Deer Trail Mountain area, Marysvale, Utah, as well as a sample from the Deer Trail mine workings from which sericite was separated. The magmatic-steam alunite and sericite were analyzed by the 4 - Maps
Using the potassium-argon laser experiment (KArLE) to date ancient, low-K chondritic meteorites
Several laboratories have been investigating the feasibility of in situ K-Ar dating for use in future landing planetary missions. One drawback of these laboratory demonstrations is the insufficient analogy of the analyzed analog samples with expected future targets. We present the results obtained using the K-Ar laser experiment (KArLE) on two old and K-poor chondritic samples, Pułtusk and Hvittis - Publications
Paleogene sedimentary basin development in southern Nevada, USA
The cause of the transition from Mesozoic and early Cenozoic crustal shortening to later extension in the western United States is debated. In many parts of the extant Sevier hinterland, now the Basin and Range Province, the sedimentary sections that provide the most direct record of that transition remain poorly studied and lack meaningful age control. In this paper, we present field characterizaAuthorsJens-Erik Lundstern, Theresa Maude Schwartz, Cameron Mark Mercer, Joseph Colgan, Jeremiah B. Workman, Leah E. MorganThe Mount Weld rare earth element deposit, Western Australia: A carbonatite-derived laterite
Carbonatite-hosted rare earth element (REE) deposits are the primary source of the world’s light REEs and have the potential to be a source of heavy REEs. The Mount Weld REE deposit in Western Australia is hosted in a lateritic sequence that reflects supergene enrichment of the underlying carbonatite complex. Similar to other carbonatite-related ore deposits, ore from Mount Weld displays extreme l
AuthorsPhilip Verplanck, Heather A. Lowers, Adam Boehlke, Jay Michael Thompson, Ganesh Bhat, Cameron Mark Mercer40Ar/39Ar geochronology of magmatic-steam alunite from Alunite Ridge and Deer Trail Mountain, Marysvale Volcanic Field, Utah: Timing and duration of miocene hydrothermal activity associated with concealed intrusions
Porphyry and epithermal deposits are important sources of base and precious metals. Most actively mined deposits have been exhumed such that ore bodies are relatively close to the surface and are therefore locatable and economic to extract. Identifying and characterizing concealed deposits, particularly more deeply buried porphyry deposits, represents a far greater challenge for mineral exploratioAuthorsCameron Mark Mercer, M. Cosca, Albert H. Hofstra, Wayne R. Premo, Robert O. Rye, Gary P. LandisInterpreting and reporting 40Ar/39Ar geochronologic data
The 40Ar/39Ar dating method is among the most versatile of geochronometers, having the potential to date a broad variety of K-bearing materials spanning from the time of Earth’s formation into the historical realm. Measurements using modern noble-gas mass spectrometers are now producing 40Ar/39Ar dates with analytical uncertainties of ∼0.1%, thereby providing precise time constraints for a wide raAuthorsAllen J. Schaen, Brian R. Jicha, Kip V. Hodges, Pieter Vermeesch, Mark E. Stelten, Cameron M. Mercer, David Phillips, Tiffany Rivera, Fred Jourdan, Erin L. Matchan, Sidney R. Hemming, Leah E. Morgan, Simon P. Kelley, William S. Cassata, Matt T. Heizler, Paulo M. Vasconcelos, Jeff A. Benowitz, Anthony A.P. Koppers, Darren F. Mark, Elizabeth M. Niespolo, Courtney J. Sprain, William E. Hames, Klaudia F. Kuiper, Brent D. Turrin, Paul R. Renne, Jake Ross, Sebastian Nomade, Hervé Guillou, Laura E. Webb, Barbara A. Cohen, Andrew T. Calvert, Nancy Joyce, Morgan Ganderød, Jan Wijbrans, Osamu Ishizuka, Huaiyu He, Adán Ramirez, Jörg Pfänder, Margarita Lopez-Martínez, Huaning Qiu, Brad S. SingerTime scales of porphyry Cu deposit formation: insights from titanium diffusion in quartz
Porphyry dikes and hydrothermal veins from the porphyry Cu-Mo deposit at Butte, Montana, contain multiple generations of quartz that are distinct in scanning electron microscope-cathodoluminescence (SEM-CL) images and in Ti concentrations. A comparison of microprobe trace element profiles and maps to SEM-CL images shows that the concentration of Ti in quartz correlates positively with CL brightnesAuthorsCelestine N. Mercer, Mark H. Reed, Cameron M. MercerNon-USGS Publications**
Torrano, Z. A., G. A. Brennecka, C. M. Mercer, S. J. Romaniello, V. K. Rai, R. R. Hines, and M. Wadhwa, 2023, Titanium and chromium isotopic compositions of calcium-aluminum-rich inclusions: Implications for the sources of isotopic anomalies and the formation of distinct isotopic reservoirs in the early Solar System: Geochimica et Cosmochimica Acta, 348, pp. 309-322, doi: 10.1016/j.gca.2023.03.018.Mercer, C. M., K. V. Hodges, B. L. Jolliff, M. C. van Soest, J.-A. Wartho, and J. R. Weirich, 2019, Exploring the Variability of Argon Loss in Apollo 17 Impact Melt Rock 77135 Using High Spatial Resolution 40Ar/39Ar Geochronology: Meteoritics & Planetary Science, vol. 54 (4), pp. 721–739, doi: 10.1111/maps.13240.Mercer, C. M., and K. V. Hodges, 2017, Diffusive Loss of Argon in Response to Melt Vein Formation in Polygenetic Impact Melt Breccias: Journal of Geophysical Research: Planets, vol. 122 (8), pp. 1650–1671, doi: 10.1002/2017JE005312.Schmitt, H. H., N. E. Petro, R. A. Wells, M. S. Robinson, B. P.Weiss, and C. M. Mercer, 2017, Revisiting the Field Geology of Taurus-Littrow: Icarus, vol. 298, pp. 2–33, doi: 10.1016/j.icarus.2016.11.042.Mercer, C. M., and K. V. Hodges, 2016, ArAR — A Software Tool to Promote the Robust Comparison of K-Ar and 40Ar/39Ar Dates Published Using Different Decay, Isotopic, and Monitor-Age Parameters: Chemical Geology, vol. 440, pp. 148–163, doi: 10.1016/j.chemgeo.2016.06.020.Mercer, C. M., K. E. Young, J. R. Weirich, K. V. Hodges, B. L. Jolliff, J.-A. Wartho, and M. C. van Soest, 2015, Refining Lunar Impact Chronology through High Spatial Resolution 40Ar/39Ar Dating of Impact Melts: Science Advances, vol. 1 (1), e1400050, doi: 10.1126/sciadv.1400050.Scully, J. E. C., A. Yin, C. T. Russell, D. L. Buczkowski, D. A. Williams, D. T. Blewett, O. Ruesch, H. Hiesinger, L. Le Corre, C. M. Mercer, R. A. Yingst, W. B. Garry, R. Jaumann, T. Roatsch, F. Preusker, R.W. Gaskell, S. E. Schr¨oder, E. Ammannito, C. M. Pieters, C. A. Raymond, and the Dawn Science Team, 2014, Geomorphology and structural geology of Saturnalia Fossae and adjacent structures in the northern hemisphere of Vesta: Icarus, vol. 244, pp. 23-40, doi: 10.1016/j.icarus.2014.01.013.Rapp, J. F., D. S. Draper, and C. M. Mercer, 2013, Anhydrous liquid line of descent of Yamato-980459 and evolution of Martian parental magmas: Meteoritics & Planetary Science, vol. 48 (10), pp. 1780–1799, doi: 10.1111/maps.12197.**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.