John Geissman

Professor and Program Head - Geosciences
geissman@utdallas.edu
972-883-2403
ROC2301G
ORCID
Tags: Geoscience

Professional Preparation

Ph.D. - Geological Sciences
University of Michigan-Ann Arbor - 1980
M.S. - Geological Sciences
University of Michigan-Ann Arbor - 1976
B.S. - Geology
University of Michigan-Ann Arbor - 1973

Research Areas

Research and Teaching Interests

Over the past decade, while on the faculty at the University of New Mexico, I have taught field geology, structural geology, tectonics, exploration geophysics, geology of New Mexico, solid earth geophysics, paleomagnetism, scientific presentations, Earth history, and physical geology. Notably, working with a colleague at the University of New Mexico, I have developed and refined the field geology course into an outstanding and also demanding/rigorous field geology experience.  I also participate in the instruction of the University of Michigan’s summer field geology course.

My research interests include the structural evolution of highly extended parts of the Basin and Range Province in the western US, Triassic paleomagnetism and magnetostratigraphy and its bearing on Colorado Plateau rotation, Pennsylvanian/ Permian redbeds along the eastern and northern margin of the Colorado Plateau, deformation along the eastern margin of the eastern Himalayan syntaxis in Southeast Asia, Precambrian paleomagnetism in the western US, pseudotachylite formation, the emplacement of shallow level igneous bodies (e.g., laccoliths and regionally extensive sill complexes), and developing improved techniques to recognize subtle yet significant differences among populations of magnetized phases in rocks whose magnetic mineralogy is dominated by magnetite and/or maghemite.

Publications

Connell, S.D., Smith, G.A., Geissman, J., and McIntosh, W., 2011, Tectonic and limatic controls on Upper Cenozoic nonmarine depositional sequences, Albuquerque Basin, Rio Grande rift, north-central New Mexico, in Hudson, M.R., and Grauch, T., ed., New Perspectives on the Rio Grande Rift: From Tectonics to Groundwater, Boulder, Geological Society of America Special Paper, in press. 2011 - Publication
Zeigler, K.E., and Geissman, J.W., 2011, Magnetostratigraphic Compilation for the Upper Triassic Chinle Group of New Mexico: Implications for regional and global correlations: Geosphere, Geological Society of America, in press. 2011 - Publication
ucas, S. G., L. H. Tanner, et al. (2011). "Position of the Triassic-Jurassic boundary and timing of the end-Triassic extinctions on land: Data from the Moenave Formation on the southern Colorado Plateau, USA." Palaeogeography, Palaeoclimatology, Palaeoecology 302: 194-205. 2011 - Publication
Godinez-Urban, A., R. S. Molina-Garza, et al. (2011). "Paleomagnetism of the Todos Santos and La Silla Formations, Chiapas: Implications for the Opening of the Gulf of Mexico." Geosphere 7: 145-158. 2011 - Publication
Geissman, J. W., Holm, D. K., Harlan, S. S., and Embree, G., 2010, Paleomagnetic evidence for rapid, high temperature formation of large-scale rheomorphic structures in the upper Pliocene Huckleberry Ridge Tuff, east-central Idaho: Geology, v. 38, p. 263-266. 2010 - Publication

Appointments

Vice President - Geological Society of America [2010–Present]
Professor of Geosciences - University of Texas at Dallas [2010–Present]
Chair - University of New Mexico [2007–2010]
Council Member - Geological Society of America [2005–Present]
Chair - University of New Mexico on Gevernance [2005–2007]
Crosby Professor - Massachusetts Institute of Technology [2004–2018]
Science Editor, Eos - American Geophysical Union [2003–2010]
Geomagnetism and Paleomagnetism Editor, Eos - American Geophysical Union [2001–2003]
Science Editor, Eos - American Geophysical Union [1999–2002]
Adjunct Full Professor - University of Michigan, Ann Arbor [1997–Present]

Awards

Distinguished Service Award - Geological Society of America [2002]
Fellow - American Geophysical Union

Additional Information

Professional and University Citizenship
Professional activities and committees:

  •  2005-present, Associate Editor, Tectonics
  •  2002, 2005 Technical Program Chair, GSA Annual Meetings
  •  2001-2010 Editor, Eos, Transactions of the American Geophysical Union
  •  2000-2001, Chair, AGU Committee on Creation Science Policy Statement
  •  2000-2004, Chair, AGU Sullivan/Perlman Committee
  •  1991, Co-Chair, Geological Society of America Rocky Mountain- South Central Regional Meeting
  •  1995-2000 Editor, Bulletin of the Geological Society of America
  •  1995-2000, Geological Society of America Publications Committee
  •  1988-1995 Associate Editor, Geological Society of America Bulletin
  •  1989-1966, 2001-5, Editorial Board, Geology
  •  1988-1999 Associate Editor, Journal of Geophysical Research
  •  1989-1991 Secretary, Geomagnetism and Paleomagnetism Section, AGU
  •  1999-present, Editorial Board, National Center for Science Education
  •  2001, Chair, Geological Society of America Rocky Mountain- South Central Regional Meeting
  •  2000, AGU representative to Teaching of Evolution Conference, Berkeley
  •  2005-Board, Building Stronger Geoscience Departments Program
  •  2005-2009 GSA Council
  •  2010-GSA Vice President
 Departmental activities and committees (at previous institutions):

  •  1981-1983, Graduate Advisory Committee, Colorado School of Mines
  •  1982-1984, Laboratory Technician, Paleomagnetism Laboratory, Colorado School of Mines
  •  1983-1984, Head, Graduate Advisory Committee, Colorado School of  Mines
  •  1984- 2010, Laboratory Technician, Paleomagnetism Laboratory,  University of New Mexico
  •  1985-1986, Undergraduate Committee, Department of Geology, UNM
  •  1985-1987, Undergraduate Honors Advisor, Department of Geology
  •  1986-1989, Graduate Committee, Department of Geology
  •  1986-1989, Computer Use Committee, Department of Geology
  •  1989-1994, Head, Graduate Committee, Department of Geology
  •  1994-1996, Co-Head, Graduate Committee, Department of Geology
  •  1990- present, Long Range Planning Committee, Department of Geology
  •  1991- 2007, Facilities Committee, Department of Geology
  •  1992-1997, Assistant Chairperson, Department of Geology
  •  1996-present, Head, Facilities Committee, Department of Earth and Planetary Sciences
  •  1998-2001, co-Chair, Department Graduate Committee
  •  2007-2010, Chair, Earth and Planetary Sciences, UNM
  •  School activities and committees (at previous institutions):
  •  1993-1996, College of Arts and Sciences Graduate Committee
  •  1994-1995, College of Arts and Sciences Senior Promotion and Tenure Committee
  •  1998-1999, Chair, College of Arts and Sciences Promotion and Tenure Committee
  •  1999-2000, Chair, College of Arts and Sciences Senior Promotion and Tenure Committee
  •  2002-2003, Chair, College of Arts and Sciences Junior Promotion and Tenure Committee
Courses and other curricula developed (at previous institutions):

  •  Physical geology
  •  Structural Geology
  •  Tectonics
  •  Earth History
  •  Field Geology
  •  Exploration Geophysics
  •  Solid Earth Geophysics
  •  New Mexico Geology
  •  Geologic Presentations
  •  Interior of the Earth
  •  Paleomagnetism         
  •  Advanced Paleomagnetism
University activities and committees (at previous institution):
  •  1982-1984, Research Committee, Colorado School of Mines
  •  1983-1984, Library Committee, Colorado School of Mines
  •  1987-1988, 1988-1989 Research Policy Committee, UNM
  •  1991- 1994, Volunteer, UNM One-On-One program
  •  1991-1992, Member, University of New Mexico Faculty Senate
  •  1994-1997, Member, University of New Mexico Faculty Senate
  •  1997-Member, Provost’s Task Force for Evaluation of Administrative and Staff Infrastructure
  •  1994-1997, Academic Freedom and Tenure Committee
  •  1997-1999, Member, University of New Mexico Faculty Senate
  •  1999-June, 2002 President UNM Faculty Senate
  •  2000-2002, UNM Strategic Plan Task Force
  •  2000-2002, UNM Planning Council
  •  1998-2002, Faculty Senate Governmental Relations Committee
  •  2003-2006, Member, UNM Conflict of Interest Committee
  •  2005-2007, Chair, UNM Committee on Governance
Honors and other Recognitions
  •  University of Michigan, 1970, Phi Eta Sigma
  •  University of Michigan, 1973, Phi Beta Kappa
  •  NSF Graduate Fellowship, Honorable Mention, 1974
  •  University of Michigan, Rackham Doctoral Dissertation Fellowship, 1978
  •  Editor’s Citation for Excellence in Reviewing, Journal of Geophysical Research, 1988
Abstracts
     Muggleton, S., Geissman, J.W., and Wawrzyniec, T.F., 2005, Magnetic fabrics as indicators of magma flow and emplacement mechanisms for the Spanish Peaks Igneous Complex (south-central Colorado): Geological Society of America Abstracts with Programs.
 
     Petronis, M.S., Geissman, J.W., and Oldow, J.S., 2005, Heterogeneous block rotations in the Mina Deflection of the central Walker Lane, west-central Nevada: Geological Society of America Abstracts with Programs, v. 37, p. 28-18.
 
     Molina-Garza, R.S., Geissman, J.W., Bodo, W., Wawrzyniec, T.F., and Muggleton, S., 2005, Paleomagnetic assessment of pseudotachylites in the Chiapas Massif, Mexico: Geological Society of America Abstracts with Programs, v. 37, p. 208-2.
 
     Geissman, J.W., Barnes, C.G., and Barnes, M.A., 2005, Paleomagnetism of Mesoproterozoic igneous rocks, West-Texas bore core: Geological Society of America Abstracts with Programs, v. 37, p. 170-10.
 
     Donohoo Hurley, L., Geissman, J.W., Fawcett, P.J., Wawrzyniec, T.F., and Goff, F., 2005, Preliminary results of the environmental magnetic record of Pleostocene Valles Caldera lacustrine sediments, New Mexico: Geological Society of America Abstracts with Programs, v. 37, p. 453.
 
     Geissman, J.W., and Zoback, M.L., 2005, What story do we begin with first?: Geological Society of America Abstracts with Programs, v. 37, p. 55-14.
 
     Ault, A.K., Wawrzyniec, T.F., Geissman, J.W., Erslev, E.A., and Fankhauser, S.D., 2005, Paleomagnetic data bearing on the age of slip along the Picuris-Pecos fault of New Mexico, southwest USA: Geological Society of America Abstracts with Programs, v. 37, p. 101-14.
 
     Zeigler, K.E., Geissman, J.W., Kelley, S., and Lucas, S.G., 2005, Magnetostratigraphy and facies variation in the Upper Triassic Salitral Formation (Chinle Group) in the Chama Basin, north-central New Mexico: Geological Society of America Abstracts with Programs, v. 37, p. 136-15.
 
     Wawrzyniec, T.F., Molina-Garza, R.S., Geissman, J.W., and Iriondo, A., 2005, A newly discovered, relic, transcurrent plate boundary—The Tonala shear zone and  paleomagnetic evaluation of the western Maya Block, SW Mexico: Geological Society of America Abstracts with Programs, v. 37, p. 28-5.
 
     Zeigler, K.E., Molina-Garza, R.S., Geissman, J.W., and Lucas, S.G., 2005, Preliminary magnetostratigraphy of the Pennsylvanian-Permian Horquilla Formation at New Well Peak, Big Hatchet Mountains, southwestern New Mexico: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. GP33A-0108.
 
     Geissman, J.W., and Ferre, E., 2005, Paleomagnetism of the mid-Paleoproterozoic Bushveld Complex Alkaline Granites, South Africa: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. GP33A-0099.
 
     Muggleton, S., Geissman, J.W., and Wawrzyniec, T.F., 2005, Paleomagnetism of Spanish Peaks, Silver Mountain, associate dike swarms, and related intrusions (south-central Colorado) : Refining the mid-Cenozoic reference paleomagnetic pole: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. GP23A-0035.
 
     Geissman, J.W., and McFadden, L.D., 2005, Earth and Planetary Sciences at UNM, the Flagship University in the Poorest State in the US--A milagro: Eos, Transactions of the American Geophysical Union, v. 86, p. ED12A-04, invited.
 
     Callahan, C.N., Geissman, J.W., Selverstone, J., and Brearley, A.J., 2005, Magnetic properties of mantle xenoliths and evidence of localized modification of the mantle beneath the Rio Puerco volcanic field, New Mexico: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. T13A-0424.
 
     Fawcett, P.J., Heikoop, J., Goff, F., Allen, C.D., Anderson, S., Donohoo Hurley, L., Geissman, J.W., Johnson, C., Woldegabriel, G., and Fessenden-Rahn, J., 2005, Climate change over a glacial-interglacial cycle from the mid_Pleistocene: A lacustrine record from the Valles Caldera, New Mexico: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. PP31A-1505.
 
     Harlan, S.S., Weese, A., Geissman, J.W., Snee, L., and Sauer, R., 2005, Paleomagnetic and 40Ar/39Ar geochronology of Tertiary intrusive and volcanic rocks in the Espanola Basin, New Mexico: Further evidence for counterclockwise vertical axis block rotations in the Rio Grande rift: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. GP33A-0087.
 
     Singer, B.S., Jicha, B.R., Kirby, B.T., Zhang, X., Geissman, J.W., and Herrero-Bervera, E., 2005, An 40Ar/39Ar age for geomagnetic instability recorded at the Albuquerque Volcanoes and Pringle Falls, Oregon: Eos, Transactions of the Amercian Geophysical Union, v. 86, p. GP21A-0019.
 
     Ferre, E., and Geissman, J.W., 2005, Paleomagnetic and rock magnetic record of transient co-seismic electric currents in fault-rocks: Earthscope National Meeting, Proceedings, p. Poster 023.
 
     Geissman, J.W., 2005, Paleomagnetism in extensional and transtensional settings; some musings, in Lee, J., Stockli, D., Henry, C.D., and Dixon, T., eds., Penrose Conference: Kinematics and geodynamics of intraplate dextral shear in eastern California and western Nevada: Mammoth Lakes.
 
     Petronis, M.S., and Geissman, J.W., 2005, Paleomagnetic evaluation of crustal-scale block rotations in the Mina Deflection and southwest Silver Peak Range and anisotropy of magnetic susceptibility data bearing ont he transport direction of the Caldelaria Hills Ignimbrite sequence, in Lee, J., Stockli, D., Henry, C.D., and Dixon, T., eds., Penrose Conference: Kinematics and geodynamics of intraplate dextral shear in eastern California and western Nevada: Mammoth Lakes.
 
     Zeigler, K.E., and Geissman, J.W., 2006, Preliminary magnetostratigraphy of the Carnian to Early Norian (Late Triassic) Lower Chinle Group, central and north-central New Mexico: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP31B-0085.
 
     Geissman, J.W., 2006, Continental red beds: How, why, and when can they be remagnetized, and what would Don Elston think?: Eos, Transactions of the Amercian Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP34A-01, invited.
 
     Peacock, G.W., Petronis, M.S., and Geissman, J.W., 2006, Anisotropy of magnetic susceptibility and paleomagnetism of the mid-Tertiary Three Peaks Laccolith, Iron Axis Province, southwest Utah: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP31A-0075.
 
     Donohoo Hurley, L., Geissman, J.W., Lucas, S.G., and Roy, M., 2006, A new look at the magnetostratigraphy and paleomagnetism of the Upper Triassic to Lower Jurassic Moenave Formation, St. George area, southwest Utah: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP31B-0092.
 
     Holm, D.K., Geissman, J.W., and Naibert, T.J., 2006, Paleomagnetism and anisotropy of magnetic susceptibility of the early Eocene Shonkin Sag Laccolith, north-central Montana: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP31A-0072.
 
     Geissman, J.W., Holm, D.K., and Harlan, S.S., 2006, Paleomagnetic and anisotropy of magnetic susceptibility (AMS) documentation of the formation of large-scale rheomorphic structures in the 2.06 Ma Huckleberry Ridge Tuff, eastern Idaho: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP11A-0062.
 
     Petronis, M.S., Odriscoll, B., Troll, V.R., Geissman, J.W., and Emeleus, C.H., 2006, The structure and emplacement of the western Granite, Isle of Rum, NW Scotland: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract GP31A-0076.
 
     Fawcett, P.J., Heikoop, J., Anderson, R., Hurley, L., Goff, F., Geissman, J.W., Johnson, C., Woldegabriel, G., Allen, C.D., and Fessenden-Rahn, J., 2006, Two mid-Pleistocene glacial cycles (MIS 14 to 10) from lacustrine sediments in the Valles Caldera, New Mexico: Eos, Transactions of the American Geophysical Union, Fall Meet. Suppl., v. 87, p. Abstract PP51B-1137.
 
     Hurley, L., Geissman, J.W., Fawcett, P.J., Wawrzyniec, T.F., and Goff, F., 2006, In investigation of environmental magnetism of the Valle Grande Pleistocene lacustrine sediments, New Mexico: Geological Society of America Abstracts with Programs, v. 38.
 
     Geissman, J.W., and Elrick, M., 2006, Variations in rock magnetic parameters in the Fort Hays Limestone, Niobrara Formation, Badito Colorado: A record of climatically controlled cycles in marine carbonate rocks?: Geological Society of America Abstracts with Programs, v. 38, p. 90.
 
     Geissman, J.W., Wawrzyniec, T.F., Molina-Garza, R.S., and Muggleton, S., 2007, Paleomagnetic investigation of the Chiapas Massif and Tonala Shear Zone, western Maya Block: Geological Society of America Abstracts with Programs, v. 39, p. 468.
 
     Wawryzniec, T., Erslev, E., Geissman, J.W., and Ault, A.K., 2007, Balancing the Laramide foreland strain field: Geological Society of America Abstracts with Programs, v. 39, p. 52.
 
     Geissman, J.W., Meyer, G., and Muggleton, S., 2007, Field geology instruction at the flagship institution in one of the poorest states in the USA: Geological Society of America Abstracts with Programs, v. 39, p. 546.
 
     Geissman, J.W., 2007, Linking paleomagnetism and rock magnetism with geologic observations: The present and future: Geological Society of America Abstracts with Programs, v. 39, p. 120.
 
     Fawcett, P.J., Heikoop, J., Anderson, R., Hurley, L., Goff, F., Woldegabriel, G., Geissman, J.W., and Allen, C.D., 2007, A long middle Pleistocene climate record (MIS 14 to 9) from lacustrine sediments in the Valles Caldera, New Mexico: Geological Society of America Abstracts with Programs, v. 39, p. 270.
 
     Fawcett, P.J., Heikoop, J., Anderson, R., Hurley, L., Goff, F., Woldegabriel, G., Geissman, J.W., and Allen, C.D., 2007, A long middle Pleistocene climate record (MIS 14 to 9) from lacustrine sediments in the Valles Caldera, New Mexico: Geological Society of America Abstracts with Programs, v. 39, p. 270.
 
     Connell, S.D., Smith, G.A., and Geissman, J.W., 2007, Climatic and tectonic influences on the development of the Albuquerque Basin and Rio Grande rift, New Mexico: Geological Society of America Abstracts with Programs, v. 39, p. 364.
 
     Burchfiel, B.C., Akciz, S., and Geissman, J.W., 2007, Pre-extrusion location of the Indochina fragment and its shear zone cicatrix in SE Tibet: Geological Society of America Abstracts with Programs, v. 39, p. 592.
 
     Zeigler, K.E., Kelley, S., Smith, G.A., and Geissman, J.W., 2007, Revision of lithstratigraphic nomenclature for the Lower Chinle Group (Late Triassic: Carnian) based on mapping in the Chama Basin, northern New Mexico: Geological Society of America Abstracts with Programs, v. 39, p. 151.
 
     Petronis, M.S., Hacker, D.B., Holm, D.K., and Geissman, J.W., 2007, Emplacement of the Miocene Iron Axis laccoliths, SW Utah: results from magnetic fabric, paleomagnetic, and field mapping studies: Geological Society of America Abstracts with Programs, v. 39, p. 5.
 
     Peacock, G.W., Arnold, B.J., Petronis, M.S., Hacker, D.B., Holm, D.K., and Geissman, J.W., 2007, Anisotropy of magnetic susceptibility and paleomagnetism of the mid-Tertiary Granite Mountain and Three Peaks laccoliths, Iron Axis Province, SW Utah: Geological Society of America Abstracts with Programs, v. 39, p. 5.
 
     Hurley, L., Geissman, J.W., and Lucas, S.G., 2007, New paleomagnetic results from the latest Triassic to earliest Jurassic Moenave Formation, southwest Utah, and northwest Arizona: Geological Society of America Abstracts with Programs, v. 39, p. 15.
 
     Zeigler, K.E., Kirkland, J., and Geissman, J.W., 2007, Preliminary paleomagnetic data from the Yellow Cat and Poison Strip members of the Lower Cretaceous Cedar Mountain Formation (Barremian-Aptian) , Green River, central Utah: Geological Society of America Abstracts with Programs, v. 39, p. 9.
 
     Ferre, E., Zechmeister, M., and Geissman, J.W., 2007, Coseismic electric currents and the pseudotachylyte magnetic black box: European Geophysical Union Geophysical Research Abstracts, v. 9, p. 02469.
 
     Zechmeister, M., FERRE, E., Carrapa, B., Caby, R., Cosca, M., and Geissman, J.W., 2007, Geologic and seismic deformation during unroofing of the Dora Maira Massif; western Alps, Italy: tectonic versus climatic control: European Geophysical Union Geophysical Research Abstracts, v. 9, p. 05124.
 
     Naibert, T.J., and Geissman, J.W., 2007, Insights into magma ascent during shallow-level crustal shortening from magnetic fabrics of the Phillipsburg Batholith, SW Montana: Eos, Trans. AGU, Fall Meeting Suppl., v. 88, p. GP21A-0122.
 
     Grow, J., Geissman, J.W., and Oldow, J.S., 2007, Paleomagnetic data bearing on the eastern and southern boundaries of the Walker Lane Belt transfer system: Eos, Trans. AGU, Fall Meeting Suppl., v. 88, p. GP21A-0110.
 
     Nyman, M.W., Ellwein, A.L., Geissman, J.W., McFadden, L.D., and Crossey, L.J., 2007, The Natural Science Program at the University of New Mexico: Geosciences play a central role in preservice treacher training: Eos Trans. AGU, Fall Meet. Suppl., v. 88, p. ED41B-0483.
 
     Dyer, J.B., Geissman, J.W., and Ramenofsky, A.F., 2007, Magnetic investigation of ancestral Puebloan Rio Grande (New Mexico) glaze wares: Eos, Transactions, American Geophysical Union, v. 88, p. GP21A-0108.
     
     Zeigler, K.E., and Geissman, J.W., 2007, Paleomagnetism and magnetostratigraphy of the Upper Triassic Chinle Group in north-central, western, and eastern New Mexico: Eos, Trans. AGU, Fall Meeting Suppl., v. 88, p. GP21A-0117.
 
     Lowry, J., Petronis, M.S., O'Driscoll, B., and Geissman, J.W., 2007, Paleomagnetic baked contact test of a Permo-Carboniferous dike intruding the Ross of Mull Granite, Isle of Mull, NW Scotland: Eos, Trans. AGU, Fall Meeting Suppl., v. 88, p. GP21A-0118.
 
     Geissman, J.W., and Elrick, M., 2007, Comparing lithologic and rock magnetic cyclicity in the Upper Cretaceous Fort Hays Limestone, southern Colorado-northern New Mexico: Eos, Trans. AGU, Fall Meet. Suppl., v. 88, p. PP23B-1345.
 
     Petronis, M.S., Peacock, G.W., Geissman, J.W., and O'Driscoll, B., 2007, magnetic mineralogy, AMS, and paleomagnetism of the mid-Tertiary Three Peaks Laccolith, Iron Asix Province, southwest Utah: Eos, Trans. AGU, Fall Meeting Suppl., v. 88, p. GP21A-0115.
     
     Holm, D.K., Geissman, J.W., Naibert, T.J., and George, N.K., 2007, Paleomagnetic and AMS results from the Early Eocene Shonkin Sag and Square Butte laccoliths, north-central Montana: Eos, Trans. AGU, Fall Meeting Suppl., v. 88, p. V43A-1103.
 
     Hurley, L.L., Geissman, J.W., Fawcett, P., Wawrzyniec, T.F., and Goff, F., 2007, Environmental magnetism of mid-Pleistocene lacustrine sediments of the Valles Caldera, New Mexico: Eos, Trans. AGU, Fall Meet. Suppl., v. 88, p. GP53B-1218.
 
     Muggleton, S.R., Geissman, J.W., Kelley, S.A., Read, A.S., and Chamberlin, R.M., 2007, Paleomagnetic data from Tertiary mafic dikes and pseudotachylites from the Sierra Ladrones, a spatially focused, large-magnitude extension rift-flank uplift, Rio Grande rift, New Mexico: Implications for Footwall Exhumation: Eos Trans. AGU, Fall Meet. Suppl., v. 88, p. GP21A-0106.
 
     Donohoo Hurley, L., Geissman, J. W., and Lucas, S. G., 2008, magnetostratigraphic correlation of the Triassic-Jurassic Moenave Formation, soiuthwest Utah and northern Arizona, to strata in the Newark and Hartford Basins: Geological Society of America Abstracts with Programs, v. 40, p. 131-2.
 
     Embree, G., Geissman, J. W., Clayton, R. W., and Millard, M., 2008, Gravity sliding and secondary deformation within the Huckleberry Ridge Tuff and subjacent Pliocene units, Fremont County, Idaho, USA: International Association of Volcanology and Chemistry of the Earth's Interior, 2008 General Assembly, p. 2-IP07.
 
     Fawcett, P. J., Werne, J., Anderson, R., Heikoop, J., Brown, E., Hurley, L., Smith, S., Berke, M., Soltow, H., Goff, F., Geissman, J. W., Woldegabriel, G., Fessenden-Rahn, J., Cisneros-Dozal, M., and Allen, C. D., 2008, Coupled warming and drought in the American Southwest during long mid-Pleistocene Interglacials (MIS 11 and 13): Eos, Transactions of the Amercian Geophysical Union, v. 89, p. PP43B-1524.
 
     Ferre, E., Ranaweera, C. K., Marsh, M., Maes, S. M., and Geissman, J. W., 2008, Magma flow sense in mafic dikes: Is grain-size dependence an alternative to the "imbrication fabric" model?: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP21D-0797.
 
     Geissman, J. W., and Grow, J. S., 2008, Paleomagnetic approaches to evaluating extensional tectonism in the western North American Cordillera: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP44A-03.
 
     Geissman, J. W., Pho, N., Burchfiel, B. C., and Muggleton, S., 2008, Paleomagnetic data from Upper Cretaceous red beds,  Northwest Vietnam (song Da Terrane), and their bearing on the extrusion history of Indochina and deformation along its margins: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. T33C-2072.
 
     Godinez-Urban, A., Molina-Garza, R. S., Iriondo, A., and Geissman, J. W., 2008, Paleomagnetism of the Todos Santos Fromation in the Maya Block, Chiapas: Preliminary Results: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP51A-0737.
 
     Grow, J. S., Geissman, J. W., and Oldow, J. S., 2008, Paleomagnetic data bearing on the evolution of hte Walker Lane Belt transfer zone from mid-Miocene to Present: An investigation of the inferred southern and eastern boundaries: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP51A-0740.
 
     Holm, D. K., Geissman, J. W., Naibert, T. J., and George, N. K., 2008, Paleomagnetic and AMS results from two layered mafic laccoliths in north-central Montana: European Geophysical Union Geophysical Research Abstracts, p. A-04377.
 
     Maes, S. M., Ferre, E., and Geissman, J. W., 2008, Magnetic stratification and the internal structure of layered intrusions: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP21D-0800.
 
     Mason, S. N., Sussman, A., Geissman, J. W., Lewis, C., Oliva-Urchia, B., Schultz-Fellenz, E., and Gardner, J., 2008, New paleomagnetic data from the Quaternary Bandelier Tuff: Implications for the tectonic evolution of the Rio Grande Rifftt: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP44A-08.
 
     Molina-Garza, R. S., Wawrzyniec, T. F., Iriondo, A., Geissman, J. W., and Muggleton, S., 2008, Deformation of Late Miocene plutons along the Tonala Shear Zone: A relict plate boundary in the eastern Tehuantepec region: Geological Society of America Abstracts with Programs, v. 40, p. 161-6.
 
     Naibert, T. J., Geissman, J. W., Holm, D. K., and Muggleton, S., 2008, Comparison of Anisotropy of magnetic susceptibiltiy (AMS) and anisotropy of anhysteretic remanent magnetization (AARM) in intrusionve igneous rocks: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. GP21D-0799.
 
     Oldow, J. S., Geissman, J. W., and Stock, J., 2008, Progressive strain reorganizaiton in Late Neogene structural stepovers, Central Walker Lane, western Great Basin: Geological Society of America Abstracts with Programs, v. 40, p. 233-6.
 
     Shearer, C. K., Papike, J. J., Burger, P. V., Karner, J., Borg, L., Gaffney, A., Neal, C., Shafer, J., Vernandez, V. A., Sharp, Z., Weiss, B., and Geissman, J. W., 2008, GRA 06129: A meteorite from a new asteroidal geochemical reservoir or Venus?: Lunar and Planetary Science Conference.
 
     ddin, A., Geissman, J. W., Sarma, J. N., and Naibert, T. J., 2008, Paleomagnetism, rock magnetism, and magnetic mineralogy of the Eocene Disang Group, Changlang area, Arunachal Pradesh, northeast India: Eos, Transactions of the Amercian Geophysical Union, v. 89, p. T33C-2084.
  
     Zeigler, K. E., and Geissman, J. W., 2008, Magnetostratigraphy of the Upper Triassic Chinle Group and implications for the age and correlation of Upper Triassic strata in North North America: Geological Society of America Abstracts with Programs, v. 40, p. 305-12.
 
     Wawrzyniec, T. F., Nance, J. D., Geissman, J. W., Molina-Garza, R. S., and Grow, J., 2009, The Tonala shear zone and capture of the Chortis Block by the Caribbean plate system, in Geological Society of America Abstracts with Programs, v. 41, p. 691.
 
     Donohoo Hurley, L., Geissman, J. W., and Lucas, S. G., 2009, The Triassic/Jurassic boundary, Colorado Plateau area, USA: magnetostratigraphic correlation of the Moenave Formation with the strata from St. Audrie's Bay, UK, Morocco, and Newark/Hartford basins, in Geological Society of America Abstracts with Programs, v. 41, p. 182.
 
     Geissman, J. W., Sussman, A., and Mason, S. N., 2009, How does the permanent record (paleomagnetic data) of crustal vertical axis rotations in the western US Cordillera compare with the growing (but short) geodetic record?, in Geological Society of America Abstracts with Programs, v. 41, p. 371.
 
     Sussman, A., Geissman, J. W., and Mason, S. N., 2009, Resolving crustal vertical-axis rotation rates since the Eocene in the western United States: Eos, Trans. AGU, Fall Meeting Suppl., v. 90, p. GP11A-0755.
 
     Feiner, K., Bianchi, V., Maes, S. M., Lehman, A., Ferre, E., and Geissman, J. W., 2009, Regional stress and basement structure controls on dike orientation in the Karoo Basin: Eos Trans. AGU, Fall Meet. Suppl., v. 90, p. V23E-2168.
 
     Mason, S. N., Geissman, J. W., and Sussman, A., 2009, Preliminary paleomagnetic results from outflow Eocene-Oligocene ash flow tuffs from the western margin of the San Luis Basin: Implications for the kinematic evolution of the Rio Grande rift: Eos Trans. AGU, Fall Meet. Suppl., v. 90, p. GP11A-0757.
 
     George, N. K., Geissman, J. W., Holm, D. K., Heizler, M., Polyak, V., Asmerom, Y., and Naibert, T. J., 2009, Paleomagnetic, geochronologic, and geochemical data suggest simultaneous emplacement of the early Eocene Shonkin Sag and Square Butte laccoliths, north-central Montana: Eos Trans. AGU, Fall Meet. Suppl., v. 90, p. GP21B-08.
 
     Geissman, J. W., Oldow, J. S., Stockli, D., and Grow, J., 2009, Timing, extent, and spatial progression of Neogene displacement transfer, southern Walker Lane, western Great Basin: Eos Trans. AGU, Fall Meet. Suppl., v. 90, p. T13C-1893.
 
     Lehman, A., Ferre, E., Geissman, J. W., Marsh, J., Marsh, M. C., Mare, L. P., Ranaweera, C. K., and Maes, S. M., 2009, Magma flow pattern in a giant dolerite sill and implications for the Karoo mantle plume hypothesis: Eos, Trans. AGU, Fall Meeting Suppl., v. 90, p. V23E-2155.
 
     Ranaweera, C. K., FERRE, E., Polteau, M. C., Marsh, M. C., Mare, L. P., Marsch, J., Maes, S. M., and Geissman, J. W., 2009, Magma flow pattern inferred from magnetic fabrics in a 100 km-long dolerite dike, Karoo LIP, South Africa: Eos, Trans. AGU, v. 90(52) Fall Meeting, p. GP43A-0837.
 
     Marsh, M. C., Ferre, E. C., Lehman, A., Ranaweera, C. K., Mare, L. P., Maes, S. M., and Geissman, J. W., 2009, Fabrics, internal zonation, and magma flow in small gabbroic sills, Karoo, South Africa: Eos, Trans. AGU, v. 90(52) Fall Meet. Suppl., p. Abstract VA21A-1978.
 
     Olsen, P. E., Kent, D. V., Mundil, R., Irmis, R., Geissman, J. W., Martz, J., and Parker, W., 2009, The Colorado Plateau coring project: the timescale and tempo of biotic change of the early Mesozoic: Eos Trans. AGU, Fall Meet. Suppl., v. 90, p. GP22A-08.
 
     Fawcett, P. J., Werne, J., Anderson, R., Heikoop, J., Brown, E., Berke, M., Smith, S., Goff, F., Hurley, L., Cisneros-Dozal, M., Schouten, S., Sinninghe Damste, J. S., Huang, Y., Toney, J. L., Fessenden-Rahn, J., Woldegabriel, G., Geissman, J. W., and Allen, C. D., 2009, Mid-Pleistocene orbital and millennial scale climate change in a 200 ky lacustrine sedimetn core from SW North America: Eos Trans. AGU, Fall Meet. Suppl., v. 90, p. PP13F-11.
     
     Zeigler, K. E., and Geissman, J. W., 2010, Magnetostratigraphic correlations of the Lower Chinle Group (Upper Triassic) in New Mexico: Age assignments and duration of the TR-4 disconformity: Geological Society of America Abstracts with Programs, v. 42, p. 648.
 
     Harlan, S. S., Geissman, J. W., and Snee, L., 2010, Paleomagnetism of Proterozoic mafic dikes, southern Wind River Mountains, Wyoming: Geological Society of America Abstracts with Programs, v. 42, p. 262.
 
     Shilpakar, P., Biholar, A., Naqi, M., Nix, C. K., Oldow, J. S., Geissman, J. W., Stockli, D. F., and Ferranti, L., 2010, Mesozoic structural localization and late Neogene and Holocene slip along the low-angle Wassuk Range front fault, central Walker Lane, western-central Nevada: Geological Society of America Abstracts with Programs, v. 42, p. 133.
 
     Hurley, L., Geissman, J. W., and Roy, M., 2010, Can differences between latest Triassic to earliest Jurassic paleomagnetic data from the American Southwest and eastern North America be resolved?: Geological Society of America Abstracts with Programs, v. 42, p. 401.
 
     Donohoo Hurley, L. L., Geissman, J. W., and Fawcett, P. J., 2010, Environmental magnetism of mid-Pleistocene lacustrine sediments, Valles Caldera, New Mexico: Geological Society of America Abstracts with Programs, v. 42, p. 52.
 
     Geissman, J. W., Grow, J. S., Oldow, J. S., and Stockli, D., 2010, Paleomagnetic data bearing on the spatial extent of the Neogene Walker Lane Belt transfer zone: Geological Society of America Abstracts with Programs, v. 42, p. 133.
 
     Mason, S. N., Geissman, J. W., and Sussman, A. J., 2010, Paleomagnetic data from Oligocene ash-flow tuffs of the eastern San Juan Volcanic field and the kinematic development of the Rio Grande rift: Complexities associated with PSV: Fall Meeting, AGU, San Francisco, Calif, 13-17 Dec., Abstract GP33C-0967.
 
     Harlan, S. S., Geissman, J. W., and Snee, L. W., 2010, Paleomagnetism of Proterozoic mafic dikes of the South Pass area, southern Wind River Mountains, Wyoming: Fall Meeting, AGU, San Francisco, Calif, 13-17 Dec., Abstract GP33C-0955.
 
     Holm, D. K., Geissman, J. W., Naibert, T. J., and George, N. K., 2010, AMS and AARM data bearing on the emplacement of the Early Eocene Shonkin Sag and Square Butte laccoliths, north-central Montana: Fall Meeting, AGU, San Francisco, Calif, 13-17 Dec.,  Abstract GP22A-06.
     
     Geissman, J. W., Ferre, E. C., Maes, S. M., and Marsch, J., 2010, Paleomagnetism of gabbroic sills forming the floor of the Early Jurassic Karoo Large Igneous Province, South Africa: Fall Meeting, AGU, San Francisco, Calif, 13-17 Dec., Abstract GP33C-0963.
 
     Lehman, A., Ferre, E. C., Maes, S. M., Geissman, J. W., Marsch, M. C., Mare, L. P., and Marsch, J., 2010, Normal and anomalous AMS fabrics in gabbroic sills: examples from the Karoo Large Igneous Province: Fall Meeting, AGU, San Francisco, Calif, 13-17 Dec.,  Abstract GP41A-1033.
 
     Lucas, S. G., Tanner, L. H., Geissman, J. W., Hurley, L., Kozur, H. W., Heckert, A., Kuerschner, W. M., and Weems, R., 2010, Timing of the end-Triassic extinctions on land: The Moenave Formation on the southern Colorado Plateau, USA: Fall Meeting, AGU, San Francisco, Calif, 13-17 Dec., Abstract B51F-0409.

News Articles

Prof Selected to Lead Geological Society of America
Dr. John Geissman, professor in the UT Dallas Department of Geosciences, has been named president of the Geological Society of America. He began his one-year term July 1. Geissman joined UT Dallas last year. His research interests include paleomagnetism and tectonics. “The opportunity for constructive cooperation among all professional geoscience organizations has never been greater,” Geissman said of his appointment. “GSA must continue to play a vibrant role in this mission, by first and foremost fostering a strong, energetic, and visible professional organization for its members and translating our importance to society.” He will address the GSA annual meeting in Minneapolis, Minn., this fall. The organization, established in 1888, encourages earth scientists to share their findings about the study of the planet.
Findings Rock Long-Held Assumptions about Ancient Mass Extinction
New evidence gathered from the Karoo Basin in South Africa sheds light on a catastrophic extinction event that occurred more than 250 million years ago and wiped out more than 90 percent of life in Earth’s oceans and about 70 percent of animal species on land.

In research to be presented Wednesday at the annual meeting of the Geological Society of America and published in the October issue of the journal Geology, a University of Texas at Dallas geologist and his colleagues describe new findings that challenge the currently accepted model of the “Great Dying” and how it affected land animals. That event occurred at the end of the Permian geologic period. 
Findings Rock Long-Held Assumptions about Ancient Mass Extinction
New evidence gathered from the Karoo Basin in South Africa sheds light on a catastrophic extinction event that occurred more than 250 million years ago and wiped out more than 90 percent of life in Earth’s oceans and about 70 percent of animal species on land.

In research to be presented Wednesday at the annual meeting of the Geological Society of America and published in the October issue of the journal Geology, a University of Texas at Dallas geologist and his colleagues describe new findings that challenge the currently accepted model of the “Great Dying” and how it affected land animals. That event occurred at the end of the Permian geologic period.