Close

• Contact Info

• Email

• Curriculum Vitae

• Webpage

Publications in VIVO

Co-author Network

Map of Science

Farmer, G Lang

Professor

Positions

• Professor, Geological Sciences

Research Areas

• Isotope Geochemistry

Research

research overview

• Dr. Farmer's research interests lie in the application of radiogenic isotope systematics to igneous petrogenesis, sedimentology, geochronology, environmental geology, crustal tectonics and in material science as applied to thermal ionization mass spectrometry.

keywords

• radiogenic isotope geochemistry, igneous petrogenesis, ion sources, tectonics, glaciology, Precambrian geology, database development, paleohydrology, water quality

Publications

selected publications

• chapter

  • Reassessing the Role of Continental Lithospheric Mantle in Cenozoic Magmatism, Southwestern North America.  57-86. 2022
  • Continental Basalts 2013
    
  • The Tlikakila complex in southern Alaska: A suprasubduction-zone ophiolite between the Wrangellia Composite terrane and North America.  Special Papers. 227-252. 2007
  • A geochemical database for western North American volcanic and intrusive rocks (NAVDAT).  Special Papers. 61-71. 2006
  • Contrasting Lower Crustal Evolution Across an Archean-Proterozoic Suture: Physical, Chemical and Geochronologic Studies of Lower Crustal Xenoliths in Southern Wyoming and Northern Colorado.  Geophysical Monograph. 139-162. 2005
  Paleoproterozoic Mojave province in northwestern Mexico? Isotopic and U-Pb zircon geochronologic studies of Precambrian and Cambrian crystalline and sedimentary rocks, Caborca, Sonora.  Special Papers. 183-198. 2005
  ... more

• conference proceeding

  • Isotopic constraints on ore-grade enrichment of rare earth elements in carbonatites: the Elk Creek carbonatite example.  1752-1755. 2019

• journal article

  • Mantle melting in regions of thick continental lithosphere : Examples from Late Cretaceous and younger volcanic rocks, Southern Rocky Mountains, Colorado (USA).  Geosphere. 1411-1440. 2024
  • Nd Isotopic Equilibration During Channelized Melt Transport Through the Lithosphere: A Feasibility Study Using Idealized Numerical Models.  G3: Geochemistry, Geophysics, Geosystems: an electronic journal of the earth sciences. 2024
  • Fluorine-rich mafic lower crust in the southern Rocky Mountains: The role of pre-enrichment in generating fluorine-rich silicic magmas and porphyry Mo deposits.  American Mineralogist: an international journal of earth and planetary materials. 1573-1596. 2023
    
  • Petrogenesis and rare earth element mineralization of the Elk Creek carbonatite, Nebraska, USA.  Ore Geology Reviews. 2022
    
  • U-Pb and Hf Isotopic Evidence on the Sources and Sinks of Grenvillian Detrital Zircons in Early Laurentia.  The Journal of Geology. 673-693. 2021
  Bulk composition of a zoned rare-earth minerals-bearing pegmatite in the Pikes Peak granite batholith near Wellington Lake, central Colorado, U.S.A..  Rocky Mountain Geology. 1-18. 2021
  Squeezing Water From a Stone: H₂O In Nominally Anhydrous Minerals From Granulite Xenoliths and Deep, Hydrous Fractional Crystallization.  Journal of Geophysical Research. Solid Earth. 2020
  
  Identifying Metasomatized Continental Lithospheric Mantle Involvement in Cenozoic Magmatism From Ta/Th Values, Southwestern North America.  G3: Geochemistry, Geophysics, Geosystems: an electronic journal of the earth sciences. 2020
  
  Formation by silicate-fluoride+phosphate melt immiscibility of REE-rich globular segregations within aplite dikes (vol 173, 65, 2018).  Contributions to Mineralogy and Petrology. 2018
  Hydrodynamic mechanism for the Laramide orogeny (vol 7, pg 183, 2011).  Geosphere. 2294-2295. 2018
  Geochronology, petrogenesis and geodynamic significance of the Visean igneous rocks in the Central Sudetes, northeastern Bohemian Massif.  Lithos. 385-405. 2018
  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. 1585-1601. 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. 116-133. 2017
  Generation and fate of glacial sediments in the central Transantarctic Mountains based on radiogenic isotopes and implications for reconstructing past ice dynamics.  Quaternary Science Reviews: the international multidisciplinary research and review journal. 98-109. 2016
  The link between volcanism and plutonism in epizonal magma systems; high-precision U-Pb zircon geochronology from the Organ Mountains caldera and batholith, New Mexico.  Contributions to Mineralogy and Petrology. 2016
  
  Zircon U-Pb ages and Hf isotopic compositions indicate multiple sources for Grenvillian detrital zircon deposited in western Laurentia.  Earth and Planetary Science Letters. 300-310. 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. 54-71. 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. 86-108. 2015
  
  Continental uplift through crustal hydration.  Geology (Boulder). 355-358. 2015
  
  Ecological changes in two contrasting lakes associated with human activity and dust transport in western Wyoming.  Limnology and Oceanography. 678-695. 2015
  
  Deep crustal anatexis, magma mixing, and the generation of epizonal plutons in the Southern Rocky Mountains, Colorado.  Contributions to Mineralogy and Petrology. 2015
  Rare Earth Element Enrichments in the Elk Creek Carbonatite.  Acta Geologica Sinica. 466-467. 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. 94-105. 2014
  Mantle lithosphere as a source of postsubduction magmatism, northern Sierra Nevada, California.  Geosphere. 1102-1124. 2013
  
  Provenance of the Neoproterozoic Johnnie Formation and Stirling Quartzite, southeastern California, determined by detrital zircon geochronology and Nd isotope geochemistry.  Precambrian Research. 182-199. 2012
  Hydrodynamic mechanism for the Laramide orogeny (vol 7, pg 183, 2011).  Geosphere. 544-545. 2012
  The accretion of aeolian dust in soils of the San Juan Mountains, Colorado, USA.  Journal of Geophysical Research: Earth Surface. 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 and the Bulletin of the Society of Economic Geologists. 451-480. 2011
  Hydrodynamic mechanism for the Laramide orogeny.  Geosphere. 183-201. 2011
  
  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. 384-393. 2010
  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. 1219-1235. 2009
  Provenance of Quaternary glacial and glacimarine sediments along the southeast Greenland margin.  Earth and Planetary Science Letters. 52-62. 2009
  Space-time-composition variations in continental magmatism during mid-Tertiary low angle subduction, western U. S.  Geochimica et Cosmochimica Acta. A355-A355. 2009
  Testing the Mojave-Sonora megashear hypothesis: Evidence from Paleoproterozoic igneous rocks and deformed Mesozoic strata in Sonora, Mexico.  Geology (Boulder). 75-78. 2009
  A positive test of east Antarctica-Laurentia juxtaposition within the Rodinia supercontinent.  Science. 235-240. 2008
  
  Mantle source volumes and the origin of the mid-Tertiary ignimbrite flare-up in the southern Rocky Mountains, western US.  Lithos. 279-294. 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. 328-346. 2008
  
  Increasing eolian dust deposition in the western United States linked to human activity.  Nature Geoscience. 189-195. 2008
  
  The role and impact of freshwater-seawater mixing zones in the maturation of regional dolomite bodies within the proto Floridan aquifer, USA.  Sedimentology. 1065-1091. 2007
  Impact of disturbed desert soils on duration of mountain snow cover.  Geophysical Research Letters. 2007
  
  A north-south transect across the central Mexican volcanic belt at ∼100°W:: Spatial distribution, petrological, geochemical, and isotopic characteristics of quaternary volcanism.  Journal of Petrology. 901-950. 2007
  Application of Sr isotopes in secondary silicate minerals to paleogroundwater hydrology: An example from K-metasomatized rocks in the western US.  Chemical Geology. 276-285. 2006
  Isotopic constraints on the provenance of fine-grained sediment in LGM tills from the Ross Embayment, Antarctica.  Earth and Planetary Science Letters. 90-107. 2006
  Unexpected dominance of parent-material strontium in a tropical forest on highly weathered soils.  Ecology. 626-632. 2005
  Tectonics of Pliocene removal of lithosphere of the Sierra Nevada, California.  Geological Society of America Bulletin. 1408-1422. 2004
  Ancient maize from Chacoan great houses: Where was it grown?.  Proceedings of the National Academy of Sciences of USA. 13111-13115. 2003
  
  Provenance of Late Quaternary ice-proximal sediments in the North Atlantic: Nd, Sr and Pb isotopic evidence.  Earth and Planetary Science Letters. 227-243. 2003
  
  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. 443-464. 2001
  
  VARIATIONS ACROSS AND ALONG A MAJOR CONTINENTAL RIFT - AN INTERDISCIPLINARY STUDY OF THE BASIN AND RANGE PROVINCE, WESTERN USA.  Tectonophysics. 57-96. 1992
  ... more

Teaching

courses taught

• GEOL 4725 - Field Based Special Topics in Geoscience
  Secondary Instructor - Summer 2019
  Explores selected geological subjects of special interest in a field setting. May be repeated up to 8 total credit hours. Same as GEOL 5725.
• GEOL 5001 - Physics and Chemistry of the Solid Earth
  Primary Instructor - Spring 2018 / Spring 2020 / Spring 2023
  Reviews the physical and chemical characteristics of the solid earth, from the core to the crust, and the processes that govern behavior through the earth. Lectures are supplemented with readings from the recent literature. Topics include convection, phase transitions, melt generation, forces of plate tectonics, origin of continents and lithosphere, continental tectonics, and earthquakes. Recommended requisite: a course in basic chemistry and a course in physics.

Background

education and training

• Ph.D., University of California-Los Angeles 1983
• B.A., University of California-San Diego 1977

awards and honors

• Fellow, conferred by Geological Society of America, The, 2014

International Activities

geographic focus

• Australia  Country
• Ecuador  Country
• Iceland  Country
• Mexico  Country
• Poland  Country

Other Profiles

ORCID iD

• http://orcid.org/0000-0003-1292-0624