Cooperative Institute for Research in Environmental Sciences

G. Lang Farmer

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.  Currently, my research group has used hafnium and neodymium isotope data from silicic sediments to investigate the paleogeography of ancient continents, used sediment isotopic data to study past instabilities in the East Antarctic Ice Sheet, investigated the origin of Mo-bearing granitic rocks in North America, and used space-time-compositions patterns in volcanic activity in western North America to assess the evolution the deep continental lithosphere beneath this region over the past 70 million years.

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 will consist of a micro-interdigitated electrode array (IDA) produced by sputtering tungsten onto a silicon or sapphire wafer. The final cell design of the device will be developed through a series of prototypes for the IDA, itself, and for a high melting temperature ceramic holder and electrical connector.  The various prototype configurations will be designed to optimize heating and electrical continuity of the IDA and to maximize the ion currents created within the liquid glass. The main goal will be to improve the ionization efficiency of lead by at least a factor of five which in order to improve the precision U-Pb age determinations for very small samples (picogram size).  A secondary goal will be to develop and commercialize a new class of ion source for use in private sector thermal ionization mass spectrometers.

 



CIRES master's of science student Aaron Hantsche sampling a Mesoproterozoic anorthosite in northern Sonora, Mexico, November 2013. Photo courtesy of Lang Farmer

View Publications

  • Muhlbauer, JG; Fedo, CM; Farmer, GL (2017), Influence of textural parameters on detrital-zircon age spectra with application to provenance and paleogeography during the Ediacaran-Terreneuvian of southwestern Laurentia. Geol. Soc. Am. Bull. Version: 1 129 (12-Nov) 1585-1601, issn: 0016-7606, ids: FL6OP, doi: 10.1130/B31611.1
  • Mazhari, N; Shafaroudi, AM; Ghaderi, M; Lackey, JS; Farmer, GL; Karimpour, MH (2017), Geochronological and geochemical characteristics of fractionated I-type granites associated with the skarn mineralization in the Sangan mining region, NE Iran. Ore Geol. Rev. Version: 1 84 116-133, issn: 0169-1368, ids: EP4PH, doi: 10.1016/j.oregeorev.2017.01.003
  • Jacob, KH; Farmer, GL; Buchwaldt, R; Bowring, SA (2015), Deep crustal anatexis, magma mixing, and the generation of epizonal plutons in the Southern Rocky Mountains, Colorado. Contrib. Mineral. Petrol. Version: 1 169 (1) , Art. No. 7, issn: 0010-7999, ids: AZ5SN, doi: 10.1007/s00410-014-1094-3
  • Jones, CH; Mahan, KH; Butcher, LA; Levandowski, WB; Farmer, GL (2015), Continental uplift through crustal hydration. Geology Version: 1 43 (4) 355-358, issn: 0091-7613, ids: CE8MX, doi: 10.1130/G36509.1
  • Lake, ET; Farmer, GL (2015), Oligo-Miocene mafic intrusions of the San Juan Volcanic Field, southwestern Colorado, and their relationship to voluminous, caldera-forming magmas. Geochim. Cosmochim. Acta Version: 1 157 86-108, issn: 0016-7037, ids: CG3XX, doi: 10.1016/j.gca.2015.02.020
  • Bagherzadeh, RM; Karimpour, MH; Farmer, GL; Stern, CR; Santos, JF; Rahimi, B; Shahri, MRH (2015), U-Pb zircon geochronology, petrochemical and Sr-Nd isotopic characteristic of Late Neoproterozoic granitoid of the Bornaward Complex (Bardaskan-NE Iran). J. Asian Earth Sci. Version: 1 111 54-71, issn: 1367-9120, ids: CT2AB, doi: 10.1016/j.jseaes.2015.05.019
  • Brahney, J; Ballantyne, AP; Kociolek, P; Leavitt, PR; Farmer, GL; Neff, JC (2015), Ecological changes in two contrasting lakes associated with human activity and dust transport in western Wyoming. Limnol. Oceanogr. Version: 1 60 (2) 678-695, issn: 0024-3590, ids: CD5KM, doi: 10.1002/lno.10050
  • Howard, AL; Farmer, GL; Amato, JM; Fedo, CM (2015), Zircon U-Pb ages and Hf isotopic compositions indicate multiple sources for Grenvillian detrital zircon deposited in western Laurentia. Earth Planet. Sci. Lett. Version: 1 432 300-310, issn: 0012-821X, ids: CY3YG, doi: 10.1016/j.epsl.2015.10.018
  • Verplanck, PL, GL Farmer, RM Kettler, HA Lowers, AE Koenig and MJ Blessington (2014), Rare Earth Element Enrichments in the Elk Creek Carbonatite. Acta Geol. Sin.-Engl. Ed. Version: 1 88 (2) 466-467, issn: 1000-9515, ids: CB9JV, doi: 10.1111/1755-6724.12373_25
  • Refsnider, KA; Miller, GH; Fogel, ML; Frechette, B; Bowden, R; Andrews, JT; Farmer, GL (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. Quat. Res. Version: 1 81 (1) 94-105, issn: 0033-5894, ids: 293FM, doi: 10.1016/j.yqres.2013.10.014
  • Farmer, GL; Glazner, AF; Kortemeier, WT; Cosca, MA; Jones, CH; Moore, JE; Schweickert, RA (2013), Mantle lithosphere as a source of postsubduction magmatism, northern Sierra Nevada, California. Geosphere Version: 1 9 (5) 1102-1124, issn: 1553-040X, ids: 273AU, doi: 10.1130/GES00885.1
  • Schoenborn, WA; Fedo, CM; Farmer, GL (2012), Provenance of the Neoproterozoic Johnnie Formation and Stirling Quartzite, southeastern California, determined by detrital zircon geochronology and Nd isotope geochemistry. Precambrian Res. Version: 1 206 182-199, issn: 0301-9268, ids: 952MM, doi: 10.1016/j.precamres.2012.02.017
  • Lawrence, CR; Neff, JC; Farmer, GL (2011), The accretion of aeolian dust in soils of the San Juan Mountains, Colorado, USA. J. Geophys. Res.-Earth Surf. Version: 1 116 , Art. No. F02013, issn: 0148-0227, ids: 768KQ, doi: 10.1029/2010JF001899
  • Jones, CH; Farmer, GL; Sageman, B; Zhong, SJ (2011), Hydrodynamic mechanism for the Laramide orogeny. Geosphere Version: 1 7 (1) 183-201, issn: 1553-040X, ids: 713IT, doi: 10.1130/GES00575.1
  • Mair, JL; Farmer, GL; Groves, DI; Hart, CJR; Goldfarb, RJ (2011), Petrogenesis of Postcollisional Magmatism at Scheelite Dome, Yukon, Canada: Evidence for a Lithospheric Mantle Source for Magmas Associated with Intrusion-Related Gold Systems. Econ. Geol. Version: 1 106 (3) 451-480, issn: 0361-0128, ids: 768ZP, doi: 10.2113/econgeo.106.3.451
  • Karimpour, MH; Stern, CR; Farmer, GL (2010), Zircon U-Pb geochronology, Sr-Nd isotope analyses, and petrogenetic study of the Dehnow diorite and Kuhsangi granodiorite (Paleo-Tethys), NE Iran. J. Asian Earth Sci. Version: 1 37 (4) 384-393, issn: 1367-9120, ids: 561OH, doi: 10.1016/j.jseaes.2009.11.001
  • Amato, JM; Lawton, TF; Mauel, DJ; Leggett, WJ; Gonzalez-Leon, CM; Farmer, GL; Wooden, JL (2009), Testing the Mojave-Sonora megashear hypothesis: Evidence from Paleoproterozoic igneous rocks and deformed Mesozoic strata in Sonora, Mexico. Geology Version: 1 37 (1) 75-78, issn: 0091-7613, ids: 394EJ, doi: 10.1130/G25240A.1
  • Amato, JM; Toro, J; Miller, EL; Gehrels, GE; Farmer, GL; Gottlieb, ES; Till, AB (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. Geol. Soc. Am. Bull. Version: 1 121 (10-Sep) 1219-1235, issn: 0016-7606, ids: 478QZ, doi: 10.1130/B26510.1
  • Verplanck, EP; Farmer, GL; Andrews, J; Dunhill, G; Millo, C (2009), Provenance of Quaternary glacial and glacimarine sediments along the southeast Greenland margin. Earth Planet. Sci. Lett. Version: 1 286 (2-Jan) 52-62, issn: 0012-821X, ids: 504WB, doi: 10.1016/j.epsl.2009.06.012
  • Farmer, GL; Bailley, T; Elkins-Tanton, LT (2008), Mantle source volumes and the origin of the mid-Tertiary ignimbrite flare-up in the southern Rocky Mountains, western US. Lithos Version: 1 International Conference on Continental Volcanism 102 (2-Jan) 279-294, Guangzhou, PEOPLES R CHINA, MAY 14-18, 2006, issn: 0024-4937, ids: 297GQ, doi: 10.1016/j.lithos.2007.08.014
  • Goodge, JW; Vervoort, JD; Fanning, CM; Brecke, DM; Farmer, GL; Williams, IS; Myrow, PM; DePaolo, DJ (2008), A positive test of east Antarctica-Laurentia juxtaposition within the Rodinia supercontinent. Science Version: 1 321 (5886) 235-240, issn: 0036-8075, ids: 324IS, doi: 10.1126/science.1159189, PubMed ID: 18621666
  • Neff, JC; Ballantyne, AP; Farmer, GL; Mahowald, NM; Conroy, JL; Landry, CC; Overpeck, JT; Painter, TH; Lawrence, CR; Reynolds, RL (2008), Increasing eolian dust deposition in the western United States linked to human activity. Nat. Geosci. Version: 1 1 (3) 189-195, issn: 1752-0894, ids: 309AZ, doi: 10.1038/ngeo133
  • Amato, JM; Boullion, AO; Serna, AM; Sanders, AE; Farmer, GL; Gehrels, GE (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. Geol. Soc. Am. Bull. Version: 1 120 (4-Mar) 328-346, issn: 0016-7606, ids: 270WM, doi: 10.1130/B26200.1
  • Painter, TH; Barrett, AP; Landry, CC; Neff, JC; Cassidy, MP; Lawrence, CR; McBride, KE; Farmer, GL (2007), Impact of disturbed desert soils on duration of mountain snow cover. Geophys. Res. Lett. Version: 1 34 (12) , Art. No. L12502, issn: 0094-8276, ids: 182VZ, doi: 10.1029/2007GL030284
  • Blatter, DL; Farmer, GL; Carmichael, ISE (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. J. Petrol. Version: 1 48 (5) 901-950, issn: 0022-3530, ids: 176ET, doi: 10.1093/petrology/egm006
  • Gaswirth, SB; Budd, DA; Farmer, GL (2007), The role and impact of freshwater-seawater mixing zones in the maturation of regional dolomite bodies within the proto Floridan aquifer, USA. Sedimentology Version: 1 54 (5) 1065-1091, issn: 0037-0746, ids: 213JX, doi: 10.1111/j.1365-3091.2007.00872.x
  • Farmer, GL; Licht, K; Swope, RJ; Andrews, J (2006), Isotopic constraints on the provenance of fine-grained sediment in LGM tills from the Ross Embayment, Antarctica. Earth Planet. Sci. Lett. Version: 1 249 (2-Jan) 90-107, issn: 0012-821X, ids: 094FZ, doi: 10.1016/j.epsl.2006.06.044
  • Fritz, DE; Farmer, GL; Verplanck, EP (2006), Application of Sr isotopes in secondary silicate minerals to paleogroundwater hydrology: An example from K-metasomatized rocks in the western US. Chem. Geol. Version: 1 235 (4-Mar) 276-285, issn: 0009-2541, ids: 120CF, doi: 10.1016/j.chemgeo.2006.07.006
  • Bern, CR; Townsend, AR; Farmer, GL (2005), Unexpected dominance of parent-material strontium in a tropical forest on highly weathered soils. Ecology Version: 1 86 (3) 626-632, issn: 0012-9658, ids: 906RJ, doi: 10.1890/03-0766
  • Farmer, L (2004), Igneous petrology. Geotimes Version: 1 49 (7) 30-31, issn: 0016-8556, ids: 836HF
  • Jones, CH; Farmer, GL; Unruh, J (2004), Tectonics of Pliocene removal of lithosphere of the Sierra Nevada, California. Geol. Soc. Am. Bull. Version: 1 116 (12-Nov) 1408-1422, issn: 0016-7606, ids: 869TH, doi: 10.1130/B25397.1
  • Farmer, GL; Barber, D; Andrews, J (2003), Provenance of Late Quaternary ice-proximal sediments in the North Atlantic: Nd, Sr and Pb isotopic evidence. Earth Planet. Sci. Lett. Version: 1 209 (2-Jan) 227-243, issn: 0012-821X, ids: 666RB, doi: 10.1016/S0012-821X(03)00068-2
  • Benson, L; Cordell, L; Vincent, K; Taylor, H; Stein, J; Farmer, GL; Futa, K (2003), Ancient maize from Chacoan great houses: Where was it grown?. Proc. Natl. Acad. Sci. U. S. A. Version: 1 100 (22) 13111-13115, issn: 0027-8424, ids: 738RF, doi: 10.1073/pnas.2135068100, PubMed ID: 14563925
  • Farmer, GL; Glazner, AF; Manley, CR (2002), Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California?. Geol. Soc. Am. Bull. Version: 1 114 (6) 754-768, issn: 0016-7606, ids: 561HQ
  • Farmer, GL; Espinoza, G; Morales, M; Martin, MW; Bowring, SA (2001), Nd isotope constraints on sources of Neoproterozoic to Early Cambrian siliciclastic sedimentary rocks in northern Sonora. J. South Am. Earth Sci. Version: 1 4th Meeting on the Geology of Northwestern Mexico and Adjacent Areas 14 (5) 437-446, HERMOSILLO, MEXICO, MAR 06-08, 2000, issn: 0895-9811, ids: 487RK
  • Condie, KC; Lee, D; Farmer, GL (2001), Tectonic setting and provenance of the Neoproterozoic Uinta Mountain and Big Cottonwood groups, northern Utah: constraints from geochemistry, Nd isotopes, and detrital modes. Sediment. Geol. Version: 1 141 443-464, issn: 0037-0738, ids: 446VH, doi: 10.1016/S0037-0738(01)00086-0
  • Manley, CR; Glazner, AF; Farmer, GL (2000), Timing of volcanism in the Sierra Nevada of California: Evidence for Pliocene delamination of the batholithic root?. Geology Version: 1 28 (9) 811-814, issn: 0091-7613, ids: 353HQ, doi: 10.1130/0091-7613(2000)028<0811:TOVITS>2.3.CO;2
  • Farmer, GL (2000), Use of multilevel covariance structure analysis to evaluate the multilevel nature of theoretical constructs. Soc. Work Res. Version: 1 24 (3) 180-191
  • Miller, JS; Glazner, AF; Farmer, GL; Suayah, IB; Keith, LA (2000), A Sr, Nd, and Pb isotopic study of mantle domains and crustal structure from Miocene volcanic rocks in the Mojave Desert, California. Geol. Soc. Am. Bull. Version: 1 112 (8) 1264-1279, issn: 0016-7606, ids: 339FD, doi: 10.1130/0016-7606(2000)112<1264:ASNAPI>2.0.CO;2
  • Aleinikoff, JN; Farmer, GL; Rye, RO; Nokleberg, WJ (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. Can. J. Earth Sci. Version: 1 37 (6) 945-956, issn: 0008-4077, ids: 332KR, doi: 10.1139/e00-006
  • Verplanck, PL; Farmer, GL; McCurry, M; Mertzman, SA (1999), The chemical and isotopic differentiation of an epizonal magma body: Organ Needle Pluton, New Mexico. J. Petrol. Version: 1 40 (4) 653-678, issn: 0022-3530, ids: 186MX, doi: 10.1093/petrology/40.4.653
  • Ball, TT; Farmer, GL (1998), Infilling history of a Neoproterozoic intracratonic basin: Nd isotope provenance studies of the Uinta Mountain Group, western United States. Precambrian Res. Version: 1 87 (2-Jan) 1-18, issn: 0301-9268, ids: ZC835, doi: 10.1016/S0301-9268(97)00051-X
  • Farmer, GL; Ball, TT (1997), Sources of Middle Proterozoic to Early Cambrian siliciclastic sedimentary rocks in the Great Basin: A Nd isotope study. Geol. Soc. Am. Bull. Version: 1 109 (9) 1193-1205, issn: 0016-7606, ids: XX223
  • FARMER, GL; GLAZNER, AF; WILSHIRE, HG; WOODEN, JL; PICKTHORN, WJ; KATZ, M (1995), ORIGIN OF LATE CENOZOIC BASALTS AT THE CIMA VOLCANIC FIELD, MOJAVE DESERT, CALIFORNIA. J. Geophys. Res.-Solid Earth Version: 1 100 (B5) 8399-8415, issn: 2169-9313, ids: QX769, doi: 10.1029/95JB00070
  • KOVALENKO, VI; TSARYEVA, GM; GOREGLYAD, AV; YARMOLYUK, VV; TROITSKY, VA; HERVIG, RL; FARMER, GL (1995), THE PERALKALINE GRANITE-RELATED KHALDZAN-BUREGTEY RARE-METAL (ZR, NB, REE) DEPOSIT, WESTERN MONGOLIA. Econ. Geol. Bull. Soc. Econ. Geol. Version: 1 90 (3) 530-547, issn: 0361-0128, ids: RQ062, doi: 10.2113/gsecongeo.90.3.530
  • VERPLANCK, PL; FARMER, GL; MCCURRY, M; MERTZMAN, S; SNEE, LW (1995), ISOTOPIC EVIDENCE ON THE ORIGIN OF COMPOSITIONAL LAYERING IN AN EPIZONAL MAGMA BODY. Earth Planet. Sci. Lett. Version: 1 136 (2-Jan) 31-41, issn: 0012-821X, ids: TH182, doi: 10.1016/0012-821X(95)00147-6
  • FARMER, GL; AYUSO, R; PLAFKER, G (1993), A COAST MOUNTAINS PROVENANCE FOR THE VALDEZ AND ORCA GROUPS, SOUTHERN ALASKA, BASED ON ND, SR, AND PB ISOTOPIC EVIDENCE. Earth Planet. Sci. Lett. Version: 1 116 (4-Jan) 9-21, issn: 0012-821X, ids: LA737, doi: 10.1016/0012-821X(93)90042-8
  • KAUFMAN, DS; CARTER, LD; MILLER, GH; FARMER, GL; BUDD, DA (1993), STRONTIUM ISOTOPIC COMPOSITION OF PLIOCENE AND PLEISTOCENE MOLLUSKS FROM EMERGED MARINE DEPOSITS, NORTH-AMERICAN ARCTIC. Can. J. Earth Sci. Version: 1 30 (3) 519-534, issn: 0008-4077, ids: LM391, doi: 10.1139/e93-041
  • BALL, TT; FARMER, GL (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 Version: 1 20 (7) 663-664, issn: 0091-7613, ids: JB677
  • GLAZNER, AF; FARMER, GL (1992), PRODUCTION OF ISOTOPIC VARIABILITY IN CONTINENTAL BASALTS BY CRYPTIC CRUSTAL CONTAMINATION. Science Version: 1 255 (5040) 72-74, issn: 0036-8075, ids: GX791, doi: 10.1126/science.255.5040.72, PubMed ID: 17739917
  • BARKER, F; FARMER, GL; AYUSO, RA; PLAFKER, G; LULL, JS (1992), THE 50-MA GRANODIORITE OF THE EASTERN GULF OF ALASKA - MELTING IN AN ACCRETIONARY PRISM IN THE FORE-ARC. J. Geophys. Res.-Solid Earth Version: 1 97 (B5) 6757-6778, issn: 0148-0227, ids: HT848, doi: 10.1029/92JB00257
  • KOVALENKO, VI; TSAREVA, GM; YARMOLYUK, VV; TROITSKY, VA; FARMER, GL; CHERNYSHEV, IV (1992), SR AND ND ISOTOPE COMPOSITION AND AGE OF RARE-METAL PERALKALINE GRANITOIDS FROM WESTERN MONGOLIA. Dokl. Akad. Nauk Version: 1 327 (6-Apr) 570-574, issn: 0869-5652, ids: KT982
  • JONES, CH; WERNICKE, BP; FARMER, GL; WALKER, JD; COLEMAN, DS; MCKENNA, LW; PERRY, FV (1992), VARIATIONS ACROSS AND ALONG A MAJOR CONTINENTAL RIFT - AN INTERDISCIPLINARY STUDY OF THE BASIN AND RANGE PROVINCE, WESTERN USA. Tectonophysics Version: 1 SYMP ON GEODYNAMICS OF RIFTING 213 (2-Jan) 57-96, GLION MONTREUX, SWITZERLAND, NOV 04-11, 1990, issn: 0040-1951, ids: JW837, doi: 10.1016/0040-1951(92)90252-2
  • FARMER, GL; BROXTON, DE; WARREN, RG; 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. Version: 1 109 (1) 53-68, issn: 0010-7999, ids: GQ268, doi: 10.1007/BF00687200
  • GLAZNER, AF; FARMER, GL; HUGHES, WT; WOODEN, JL; PICKTHORN, W (1991), CONTAMINATION OF BASALTIC MAGMA BY MAFIC CRUST AT AMBOY AND PISGAH CRATERS, MOJAVE DESERT, CALIFORNIA. Version: 1 JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS 96 (B8) 13673-13691, issn: 0148-0227, ids: FY298, doi: 10.1029/91JB00175
  • FARMER, GL; TEGTMEYER, KJ (1991), ND ISOTOPIC GRADIENTS IN UPPER CRUSTAL MAGMA CHAMBERS - EVIDENCE FOR INSITU MAGMA-WALL-ROCK INTERACTION - REPLY. Geology Version: 1 19 (2) 186-187, issn: 0091-7613, ids: EV835
  • BALL, TT; FARMER, GL (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 Version: 1 19 (4) 360-363, issn: 0091-7613, ids: FE841, doi: 10.1130/0091-7613(1991)019<0360:IOTGNM>2.3.CO;2
  • TEGTMEYER, KJ; FARMER, GL (1990), ND ISOTOPIC GRADIENTS IN UPPER CRUSTAL MAGMA CHAMBERS - EVIDENCE FOR INSITU MAGMA WALL-ROCK INTERACTION. Geology Version: 1 18 (1) 5-9, issn: 0091-7613, ids: CJ520, doi: 10.1130/0091-7613(1990)018<0005:NIGIUC>2.3.CO;2
  • INGRAM, BL; HEIN, JR; FARMER, GL (1990), AGE-DETERMINATIONS AND GROWTH-RATES OF PACIFIC FERROMANGANESE DEPOSITS USING STRONTIUM ISOTOPES. Geochim. Cosmochim. Acta Version: 1 54 (6) 1709-1721, issn: 0016-7037, ids: DK546, doi: 10.1016/0016-7037(90)90402-7
  • FARMER, GL; PERRY, FV; SEMKEN, S; CROWE, B; CURTIS, D; DEPAOLO, DJ (1989), ISOTOPIC EVIDENCE ON THE STRUCTURE AND ORIGIN OF SUBCONTINENTAL LITHOSPHERIC MANTLE IN SOUTHERN NEVADA. Version: 1 JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS 94 (B6) 7885-7898, issn: 0148-0227, ids: AA786, doi: 10.1029/JB094iB06p07885
  • FARMER, GL and DJ DEPAOLO (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 Version: 1 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. Version: 1 310 (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 Version: 1 88 (NB4) 3379-3401
  • FARMER, GL and AL BOETTCHER (1981), PETROLOGIC AND CRYSTAL-CHEMICAL SIGNIFICANCE OF SOME DEEP-SEATED PHLOGOPITES. Am. Miner. Version: 1 66 (1-Nov) 1154-1163