Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

G. Lang Farmer

Research Interests

My research centers on applications of trace element abundances and radiogenic isotopic data from natural materials to study the origin and evolution of Earth's lithosphere.  Current projects include the use hafnium and neodymium isotope data from siliciclastic sediments to investigate the paleogeography of ancient continents and "big data" studies of space-time-compositions patterns in Cenozoic volcanic activity in western North America to assess the evolution the deep continental lithosphere beneath this region over the past 70 million years, as illustrated in below diagram.

Current Research

"Development of MicroInterdigitated Electrode Arrays as Ion Sources for TIMS", Funding from National Science Foundation

Thermal ionization mass spectrometry is the technique of choice for high precision determinations of the isotopic abundances of elements found in both natural and manufactured materials. However, the precision of isotopic measurements performed in this fashion depends on the efficiency of the techniques used in the mass spectrometer to generate ions from elements extracted from sample materials. This project involves an effort to improve the ionization efficiency of high temperature (<1,300oC) liquid glass ion emitters, a type of metal ion source that is routinely used in thermal ionization mass spectrometry but that typically only ionizes one in every ten of the metal atoms loaded into the instrument for analysis. The approach will be to increase the proportion of metal ions generated in the liquid glass using electrolysis techniques, in which the liquid glass will serve as an electrolyte when placed in contact with two metal electrodes of opposite electrical polarity (an “electrochemical cell”). The electrochemical cell consists of a micro-interdigitated electrode array (IDA) produced by sputtering tungsten onto a silicon or sapphire wafer.  Preliminary studies show that our prototype IDA can induce electrochemical reactions in molten leaded glass and when placed in a thermal ionization mass spectrometry, a differential voltage across our IDA results in variation in the  Pb+ "beam" that reaches the collector end of our thermal ionization mass spectrometer.  These results provide a proof of concept of our approach and represent the first steps towards improving the ionization efficiency of liquid glass ion emitters.



Smoothed 2-D histogram that shows neodymium isotopic compositions (eNd) and ratios of trace elements tantalum and thorium in less than 40 million year old basalts in southwestern United States.  Basalts are volcanic rocks with relatively low silica (SiO2) abundances ( < 52 wt. % SiO2).  The plot shows that there are multiple regions on this plot that have high data densities (red regions) and can be used to identify specific basalt subpopulations in southwestern U.S.

View Publications

  • Chin, EJ; Curran, ST; Farmer, GL. (Oct 2020). Squeezing Water From a Stone: H2O In Nominally Anhydrous Minerals From Granulite Xenoliths and Deep, Hydrous Fractional Crystallization. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH , 125(10). 10.1029/2020JB020416
  • Farmer, GL; Fritz, DE; Glazner, AF. (May 2020). Identifying Metasomatized Continental Lithospheric Mantle Involvement in Cenozoic Magmatism From Ta/Th Values, Southwestern North America. GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS , 21(5). 10.1029/2019GC008499
  • Verplanck, PL; Farmer, GL; Johnson, CA; Lowers, HA. (2019). Isotopic constraints on ore-grade enrichment of rare earth elements in carbonatites: the Elk Creek carbonatite example. LIFE WITH ORE DEPOSITS ON EARTH, PROCEEDINGS OF THE 15TH SGA BIENNIAL MEETING, 2019, VOLS 1-4, 1752-1755.
  • Farmer, DK; Vance, ME; Abbatt, JPD; Abeleira, A; Alves, MR; Arata, C; Boedicker, E; Bourne, S; Cardoso-Saldana, F; Corsi, R; DeCarlo, PF; Goldstein, AH; Grassian, VH; Ruiz, LH; Jimenez, JL; Kahan, TF; Katz, EF; Mattila, JM; Nazaroff, WW; Novoselac, A; OBrien, RE; Or, VW; Patel, S; Sankhyan, S; Stevens, PS; Tian, Y; Wade, M; Wang, C; Zhou, S; Zhou, Y. (1-Aug 2019). Overview of HOMEChem: House Observations of Microbial and Environmental Chemistry. ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS, 21(8), 1280-1300. 10.1039/c9em00228f
  • Jastrzebski, M, K Machowiak, E Krzeminska, GL Farmer, AN Larionov, M Murtezi, J Majka, S Sergeev, EM Ripley and M Whitehouse. (SEP 2018). Geochronology, petrogenesis and geodynamic significance of the Visean igneous rocks in the Central Sudetes, northeastern Bohemian Massif. LITHOS, 316, 385-405. 10.1016/j.lithos.2018.07.034
  • Stern, CR, JM Allaz, MB Raschke, GL Farmer, MA Skewes and JT Ross. (AUG 2018). Formation by silicate-fluoride plus phosphate melt immiscibility of REE-rich globular segregations within aplite dikes. CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 173(8). 10.1007/s00410-018-1497-7
  • Muhlbauer, JG, CM Fedo and GL Farmer. (NOV-DEC 2017). Influence of textural parameters on detrital-zircon age spectra with application to provenance and paleogeography during the Ediacaran-Terreneuvian of southwestern Laurentia. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 129(12-Nov), 1585-1601. 10.1130/B31611.1
  • Mazhari, N, AM Shafaroudi, M Ghaderi, JS Lackey, GL Farmer and MH Karimpour. (APR 2017). Geochronological and geochemical characteristics of fractionated I-type granites associated with the skarn mineralization in the Sangan mining region, NE Iran. ORE GEOLOGY REVIEWS, 84, 116-133. 10.1016/j.oregeorev.2017.01.003
  • Howard, AL, GL Farmer, JM Amato and CM Fedo. (15-Dec 2015). Zircon U-Pb ages and Hf isotopic compositions indicate multiple sources for Grenvillian detrital zircon deposited in western Laurentia. EARTH AND PLANETARY SCIENCE LETTERS, 432, 300-310. 10.1016/j.epsl.2015.10.018
  • Bagherzadeh, RM, MH Karimpour, GL Farmer, CR Stern, JF Santos, B Rahimi and MRH Shahri. (1-Nov 2015). U-Pb zircon geochronology, petrochemical and Sr-Nd isotopic characteristic of Late Neoproterozoic granitoid of the Bornaward Complex (Bardaskan-NE Iran). JOURNAL OF ASIAN EARTH SCIENCES, 111, 54-71. 10.1016/j.jseaes.2015.05.019
  • Lake, ET and GL Farmer. (15-May 2015). Oligo-Miocene mafic intrusions of the San Juan Volcanic Field, southwestern Colorado, and their relationship to voluminous, caldera-forming magmas. GEOCHIMICA ET COSMOCHIMICA ACTA, 157, 86-108. 10.1016/j.gca.2015.02.020
  • Jones, CH, KH Mahan, LA Butcher, WB Levandowski and GL Farmer. (APR 2015). Continental uplift through crustal hydration. GEOLOGY, 43(4), 355-358. 10.1130/G36509.1
  • Brahney, J, AP Ballantyne, P Kociolek, PR Leavitt, GL Farmer and JC Neff. (MAR 2015). Ecological changes in two contrasting lakes associated with human activity and dust transport in western Wyoming. LIMNOLOGY AND OCEANOGRAPHY, 60(2), 678-695. 10.1002/lno.10050
  • Jacob, KH, GL Farmer, R Buchwaldt and SA Bowring. (JAN 2015). Deep crustal anatexis, magma mixing, and the generation of epizonal plutons in the Southern Rocky Mountains, Colorado. CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 169(1). 10.1007/s00410-014-1094-3
  • Verplanck, PL, GL Farmer, RM Kettler, HA Lowers, AE Koenig and MJ Blessington. (DEC 2014). Rare Earth Element Enrichments in the Elk Creek Carbonatite. ACTA GEOLOGICA SINICA-ENGLISH EDITION, 88(2), 466-467. 10.1111/1755-6724.12373_25
  • Refsnider, KA, GH Miller, ML Fogel, B Frechette, R Bowden, JT Andrews and GL Farmer. (JAN 2014). Subglacially precipitated carbonates record geochemical interactions and pollen preservation at the base of the Laurentide Ice Sheet on central Baffin Island, eastern Canadian Arctic. QUATERNARY RESEARCH, 81(1), 94-105. 10.1016/j.yqres.2013.10.014
  • Farmer, GL, AF Glazner, WT Kortemeier, MA Cosca, CH Jones, JE Moore and RA Schweickert. (OCT 2013). Mantle lithosphere as a source of postsubduction magmatism, northern Sierra Nevada, California. GEOSPHERE, 9(5), 1102-1124. 10.1130/GES00885.1
  • Schoenborn, WA, CM Fedo and GL Farmer. (JUN 2012). Provenance of the Neoproterozoic Johnnie Formation and Stirling Quartzite, southeastern California, determined by detrital zircon geochronology and Nd isotope geochemistry. PRECAMBRIAN RESEARCH, 206, 182-199. 10.1016/j.precamres.2012.02.017
  • Mair, JL, GL Farmer, DI Groves, CJR Hart and RJ Goldfarb. (MAY 2011). Petrogenesis of Postcollisional Magmatism at Scheelite Dome, Yukon, Canada: Evidence for a Lithospheric Mantle Source for Magmas Associated with Intrusion-Related Gold Systems. ECONOMIC GEOLOGY, 106(3), 451-480. 10.2113/econgeo.106.3.451
  • Lawrence, CR, JC Neff and GL Farmer. (20-May 2011). The accretion of aeolian dust in soils of the San Juan Mountains, Colorado, USA. JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, 116. 10.1029/2010JF001899
  • Jones, CH, GL Farmer, B Sageman and SJ Zhong. (FEB 2011). Hydrodynamic mechanism for the Laramide orogeny. GEOSPHERE, 7(1), 183-201. 10.1130/GES00575.1
  • Karimpour, MH, CR Stern and GL Farmer. (1-Mar 2010). Zircon U-Pb geochronology, Sr-Nd isotope analyses, and petrogenetic study of the Dehnow diorite and Kuhsangi granodiorite (Paleo-Tethys), NE Iran. JOURNAL OF ASIAN EARTH SCIENCES, 37(4), 384-393. 10.1016/j.jseaes.2009.11.001
  • Verplanck, EP, GL Farmer, J Andrews, G Dunhill and C Millo. (30-Aug 2009). Provenance of Quaternary glacial and glacimarine sediments along the southeast Greenland margin. EARTH AND PLANETARY SCIENCE LETTERS, 286(2-Jan), 52-62. 10.1016/j.epsl.2009.06.012
  • Amato, JM, J Toro, EL Miller, GE Gehrels, GL Farmer, ES Gottlieb and AB Till. (SEP 2009). Late Proterozoic-Paleozoic evolution of the Arctic Alaska-Chukotka terrane based on U-Pb igneous and detrital zircon ages: Implications for Neoproterozoic paleogeographic reconstructions. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 121(10-Sep), 1219-1235. 10.1130/B26510.1
  • Amato, JM, TF Lawton, DJ Mauel, WJ Leggett, CM Gonzalez-Leon, GL Farmer and JL Wooden. (JAN 2009). Testing the Mojave-Sonora megashear hypothesis: Evidence from Paleoproterozoic igneous rocks and deformed Mesozoic strata in Sonora, Mexico. GEOLOGY, 37(1), 75-78. 10.1130/G25240A.1
  • Amato, JM, AO Boullion, AM Serna, AE Sanders, GL Farmer and GE Gehrels. (MAR-APR 2008). Evolution of the Mazatzal province and the timing of the Mazatzal orogeny: Insights from U-Pb geochronology and geochemistry of igneous and metasedimentary rocks in southern New Mexico. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 120(4-Mar), 328-346. 10.1130/B26200.1
  • Goodge, JW, JD Vervoort, CM Fanning, DM Brecke, GL Farmer, IS Williams, PM Myrow and DJ DePaolo. (11-Jul 2008). A positive test of east Antarctica-Laurentia juxtaposition within the Rodinia supercontinent. SCIENCE, 321(5886), 235-240. 10.1126/science.1159189
  • Neff, JC, AP Ballantyne, GL Farmer, NM Mahowald, JL Conroy, CC Landry, JT Overpeck, TH Painter, CR Lawrence and RL Reynolds. (MAR 2008). Increasing eolian dust deposition in the western United States linked to human activity. NATURE GEOSCIENCE, 1(3), 189-195. 10.1038/ngeo133
  • Farmer, GL, T Bailley and LT Elkins-Tanton. (APR 2008). Mantle source volumes and the origin of the mid-Tertiary ignimbrite flare-up in the southern Rocky Mountains, western US. LITHOS, 102(2-Jan), 279-294. 10.1016/j.lithos.2007.08.014
  • Gaswirth, SB, DA Budd and GL Farmer. (OCT 2007). The role and impact of freshwater-seawater mixing zones in the maturation of regional dolomite bodies within the proto Floridan aquifer, USA. SEDIMENTOLOGY, 54(5), 1065-1091. 10.1111/j.1365-3091.2007.00872.x
  • Painter, TH, AP Barrett, CC Landry, JC Neff, MP Cassidy, CR Lawrence, KE McBride and GL Farmer. (23-Jun 2007). Impact of disturbed desert soils on duration of mountain snow cover. GEOPHYSICAL RESEARCH LETTERS, 34(12). 10.1029/2007GL030284
  • Blatter, DL, GL Farmer and ISE Carmichael. (MAY 2007). A north-south transect across the central Mexican volcanic belt at similar to 100 degrees W: Spatial distribution, petrological, geochemical, and isotopic characteristics of quaternary volcanism. JOURNAL OF PETROLOGY, 48(5), 901-950. 10.1093/petrology/egm006
  • Farmer, GL, K Licht, RJ Swope and J Andrews. (15-Sep 2006). Isotopic constraints on the provenance of fine-grained sediment in LGM tills from the Ross Embayment, Antarctica. EARTH AND PLANETARY SCIENCE LETTERS, 249(2-Jan), 90-107. 10.1016/j.epsl.2006.06.044
  • Fritz, DE, GL Farmer and EP Verplanck. (15-Dec 2006). Application of Sr isotopes in secondary silicate minerals to paleogroundwater hydrology: An example from K-metasomatized rocks in the western US. CHEMICAL GEOLOGY, 235(4-Mar), 276-285. 10.1016/j.chemgeo.2006.07.006
  • Bern, CR, AR Townsend and GL Farmer. (MAR 2005). Unexpected dominance of parent-material strontium in a tropical forest on highly weathered soils. ECOLOGY, 86(3), 626-632. 10.1890/03-0766
  • Farmer, L. (JUL 2004). Igneous petrology. GEOTIMES, 49(7), 30-31.
  • Jones, CH, GL Farmer and J Unruh. (NOV-DEC 2004). Tectonics of Pliocene removal of lithosphere of the Sierra Nevada, California. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 116(12-Nov), 1408-1422. 10.1130/B25397.1
  • Benson, L, L Cordell, K Vincent, H Taylor, J Stein, GL Farmer and K Futa. (28-Oct 2003). Ancient maize from Chacoan great houses: Where was it grown?. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 100(22), 13111-13115. 10.1073/pnas.2135068100
  • Farmer, GL, D Barber and J Andrews. (15-Apr 2003). Provenance of Late Quaternary ice-proximal sediments in the North Atlantic: Nd, Sr and Pb isotopic evidence. EARTH AND PLANETARY SCIENCE LETTERS, 209(2-Jan), 227-243. 10.1016/S0012-821X(03)00068-2
  • Farmer, GL, AF Glazner and CR Manley. (JUN 2002). Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California?. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 114(6), 754-768.
  • Farmer, GL, G Espinoza, M Morales, MW Martin and SA Bowring. (OCT 2001). Nd isotope constraints on sources of Neoproterozoic to Early Cambrian siliciclastic sedimentary rocks in northern Sonora. JOURNAL OF SOUTH AMERICAN EARTH SCIENCES, 14(5), 437-446.
  • Condie, KC, D Lee and GL Farmer. (1-Jun 2001). Tectonic setting and provenance of the Neoproterozoic Uinta Mountain and Big Cottonwood groups, northern Utah: constraints from geochemistry, Nd isotopes, and detrital modes. SEDIMENTARY GEOLOGY, 141, 443-464. 10.1016/S0037-0738(01)00086-0
  • Farmer, GL. (SEP 2000). Use of multilevel covariance structure analysis to evaluate the multilevel nature of theoretical constructs. Soc. Work Res., 24(3), 180-191.
  • Manley, CR, AF Glazner and GL Farmer. (SEP 2000). Timing of volcanism in the Sierra Nevada of California: Evidence for Pliocene delamination of the batholithic root?. GEOLOGY, 28(9), 811-814. 10.1130/0091-7613(2000)028<0811:TOVITS>2.3.CO;2
  • Miller, JS, AF Glazner, GL Farmer, IB Suayah and LA Keith. (AUG 2000). A Sr, Nd, and Pb isotopic study of mantle domains and crustal structure from Miocene volcanic rocks in the Mojave Desert, California. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 112(8), 1264-1279. 10.1130/0016-7606(2000)112<1264:ASNAPI>2.0.CO;2
  • Aleinikoff, JN, GL Farmer, RO Rye and WJ Nokleberg. (JUN 2000). Isotopic evidence for the sources of Cretaceous and Tertiary granitic rocks, east-central Alaska: implications for the tectonic evolution of the Yukon-Tanana Terrane. CANADIAN JOURNAL OF EARTH SCIENCES, 37(6), 945-956. 10.1139/e00-006
  • Verplanck, PL, GL Farmer, M McCurry and SA Mertzman. (APR 1999). The chemical and isotopic differentiation of an epizonal magma body: Organ Needle Pluton, New Mexico. JOURNAL OF PETROLOGY, 40(4), 653-678. 10.1093/petrology/40.4.653
  • Ball, TT and GL Farmer. (JAN 1998). Infilling history of a Neoproterozoic intracratonic basin: Nd isotope provenance studies of the Uinta Mountain Group, western United States. PRECAMBRIAN RESEARCH, 87(2-Jan), 1-18. 10.1016/S0301-9268(97)00051-X
  • Farmer, GL and TT Ball. (SEP 1997). Sources of Middle Proterozoic to Early Cambrian siliciclastic sedimentary rocks in the Great Basin: A Nd isotope study. GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 109(9), 1193-1205.
  • FARMER, GL, AF GLAZNER, HG WILSHIRE, JL WOODEN, WJ PICKTHORN and M KATZ. (10-May 1995). ORIGIN OF LATE CENOZOIC BASALTS AT THE CIMA VOLCANIC FIELD, MOJAVE DESERT, CALIFORNIA. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 100(B5), 8399-8415. 10.1029/95JB00070
  • KOVALENKO, VI, GM TSARYEVA, AV GOREGLYAD, VV YARMOLYUK, VA TROITSKY, RL HERVIG and GL FARMER. (MAY 1995). THE PERALKALINE GRANITE-RELATED KHALDZAN-BUREGTEY RARE-METAL (ZR, NB, REE) DEPOSIT, WESTERN MONGOLIA. ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS, 90(3), 530-547. 10.2113/gsecongeo.90.3.530
  • VERPLANCK, PL, GL FARMER, M MCCURRY, S MERTZMAN and LW SNEE. (NOV 1995). ISOTOPIC EVIDENCE ON THE ORIGIN OF COMPOSITIONAL LAYERING IN AN EPIZONAL MAGMA BODY. EARTH AND PLANETARY SCIENCE LETTERS, 136(2-Jan), 31-41. 10.1016/0012-821X(95)00147-6
  • FARMER, GL, R AYUSO and G PLAFKER. (APR 1993). A COAST MOUNTAINS PROVENANCE FOR THE VALDEZ AND ORCA GROUPS, SOUTHERN ALASKA, BASED ON ND, SR, AND PB ISOTOPIC EVIDENCE. EARTH AND PLANETARY SCIENCE LETTERS, 116(4-Jan), 9-21. 10.1016/0012-821X(93)90042-8
  • KAUFMAN, DS, LD CARTER, GH MILLER, GL FARMER and DA BUDD. (MAR 1993). STRONTIUM ISOTOPIC COMPOSITION OF PLIOCENE AND PLEISTOCENE MOLLUSKS FROM EMERGED MARINE DEPOSITS, NORTH-AMERICAN ARCTIC. CANADIAN JOURNAL OF EARTH SCIENCES, 30(3), 519-534. 10.1139/e93-041
  • KOVALENKO, VI, GM TSAREVA, VV YARMOLYUK, VA TROITSKY, GL FARMER and IV CHERNYSHEV. (1992). SR AND ND ISOTOPE COMPOSITION AND AGE OF RARE-METAL PERALKALINE GRANITOIDS FROM WESTERN MONGOLIA. DOKLADY AKADEMII NAUK, 327(6-Apr), 570-574.
  • JONES, CH, BP WERNICKE, GL FARMER, JD WALKER, DS COLEMAN, LW MCKENNA and FV PERRY. (30-Oct 1992). VARIATIONS ACROSS AND ALONG A MAJOR CONTINENTAL RIFT - AN INTERDISCIPLINARY STUDY OF THE BASIN AND RANGE PROVINCE, WESTERN USA. TECTONOPHYSICS, 213(2-Jan), 57-96. 10.1016/0040-1951(92)90252-2
  • GLAZNER, AF and GL FARMER. (3-Jan 1992). PRODUCTION OF ISOTOPIC VARIABILITY IN CONTINENTAL BASALTS BY CRYPTIC CRUSTAL CONTAMINATION. SCIENCE, 255(5040), 72-74. 10.1126/science.255.5040.72
  • BARKER, F, GL FARMER, RA AYUSO, G PLAFKER and JS LULL. (10-May 1992). THE 50-MA GRANODIORITE OF THE EASTERN GULF OF ALASKA - MELTING IN AN ACCRETIONARY PRISM IN THE FORE-ARC. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 97(B5), 6757-6778. 10.1029/92JB00257
  • BALL, TT and GL FARMER. (JUL 1992). IDENTIFICATION OF 2.0 TO 2.4 GA ND MODEL AGE CRUSTAL MATERIAL IN THE CHEYENNE BELT, SOUTHEASTERN WYOMING - IMPLICATIONS FOR PROTEROZOIC ACCRETIONARY TECTONICS AT THE SOUTHERN MARGIN OF THE WYOMING CRATON - REPLY. GEOLOGY, 20(7), 663-664.
  • FARMER, GL, DE BROXTON, RG WARREN and W PICKTHORN. (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. CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 109(1), 53-68. 10.1007/BF00687200
  • GLAZNER, AF, GL FARMER, WT HUGHES, JL WOODEN and W PICKTHORN. (30-Jul 1991). CONTAMINATION OF BASALTIC MAGMA BY MAFIC CRUST AT AMBOY AND PISGAH CRATERS, MOJAVE DESERT, CALIFORNIA. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS, 96(B8), 13673-13691. 10.1029/91JB00175
  • FARMER, GL and KJ TEGTMEYER. (FEB 1991). ND ISOTOPIC GRADIENTS IN UPPER CRUSTAL MAGMA CHAMBERS - EVIDENCE FOR INSITU MAGMA-WALL-ROCK INTERACTION - REPLY. GEOLOGY, 19(2), 186-187.
  • BALL, TT and GL FARMER. (APR 1991). IDENTIFICATION OF 2.0 TO 2.4-GA ND MODEL AGE CRUSTAL MATERIAL IN THE CHEYENNE BELT, SOUTHEASTERN WYOMING - IMPLICATIONS FOR PROTEROZOIC ACCRETIONARY TECTONICS AT THE SOUTHERN MARGIN OF THE WYOMING CRATON. GEOLOGY, 19(4), 360-363. 10.1130/0091-7613(1991)019<0360:IOTGNM>2.3.CO;2
  • INGRAM, BL, JR HEIN and GL FARMER. (JUN 1990). AGE-DETERMINATIONS AND GROWTH-RATES OF PACIFIC FERROMANGANESE DEPOSITS USING STRONTIUM ISOTOPES. GEOCHIMICA ET COSMOCHIMICA ACTA, 54(6), 1709-1721. 10.1016/0016-7037(90)90402-7
  • TEGTMEYER, KJ and GL FARMER. (JAN 1990). ND ISOTOPIC GRADIENTS IN UPPER CRUSTAL MAGMA CHAMBERS - EVIDENCE FOR INSITU MAGMA WALL-ROCK INTERACTION. GEOLOGY, 18(1), 5-9. 10.1130/0091-7613(1990)018<0005:NIGIUC>2.3.CO;2
  • FARMER, GL, FV PERRY, S SEMKEN, B CROWE, D CURTIS and DJ DEPAOLO. (10-Jun 1989). ISOTOPIC EVIDENCE ON THE STRUCTURE AND ORIGIN OF SUBCONTINENTAL LITHOSPHERIC MANTLE IN SOUTHERN NEVADA. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS, 94(B6), 7885-7898. 10.1029/JB094iB06p07885
  • FARMER, GL and DJ DEPAOLO. (AUG 1987). ND AND SR ISOTOPE STUDY OF HYDROTHERMALLY ALTERED GRANITE AT SAN-MANUEL, ARIZONA - IMPLICATIONS FOR ELEMENT MIGRATION PATHS DURING THE FORMATION OF PORPHYRY COPPER ORE-DEPOSITS. ECON GEOL, 82(5), 1142-1151.
  • DEPAOLO, DJ and GL FARMER. (1984). ISOTOPIC DATA BEARING ON THE ORIGIN OF MESOZOIC AND TERTIARY GRANITIC-ROCKS IN THE WESTERN UNITED-STATES. Philos. Trans. R. Soc. Lond. Ser. A-Math. Phys. Eng. Sci., 310(1514), 743-753.
  • FARMER, GL and DJ DEPAOLO. (1983). ORIGIN OF MESOZOIC AND TERTIARY GRANITE IN THE WESTERN UNITED-STATES AND IMPLICATIONS FOR PRE-MESOZOIC CRUSTAL STRUCTURE .1. ND AND SR ISOTOPIC STUDIES IN THE GEOCLINE OF THE NORTHERN GREAT-BASIN. J. Geophys. Res., 88(NB4), 3379-3401.
  • FARMER, GL and AL BOETTCHER. (1981). PETROLOGIC AND CRYSTAL-CHEMICAL SIGNIFICANCE OF SOME DEEP-SEATED PHLOGOPITES. Am. Miner., 66(1-Nov), 1154-1163.