Jo Laird
Associate Professor of Geology
Metamorphic Petrology
Hydrogeology
Ph.D. California Institute of Technology, 1977
email address: jl@cisunix.unh.edu
My main interest is metamorphic petrology, both theoretical and applied to regional geology.
Research is centered on metamorphism of mafic, calc-silicate, and pelitic rocks and the geologic history of these rocks within the Northern Appalachian Mountains. Methods include petrography, electron microprobe analysis, geothermobarometry, reaction space analysis, X-ray diffraction, and 40Ar/39Ar age dating of amphiboles (with the USGS and Princeton University).
Recent applied petrologic research combined with field and structural studies with W.A. Bothner (UNH) and our graduate and undergraduate students includes: 1) The metamorphism and structural history of a high-P facies series metamorphic terrane, north-central Vermont, 2) polymetamorphic and deformational history about the Taconian line, Vermont, and 3) Polymetamorphic history of calc-silicate, pelitic, and felsic rocks, southeastern New Hampshire. Age dating in Vermont constrains the distribution of Acadian, Taconian, and older metamorphism.
Masters theses completed include those of Toti Larson (1999), Steve Allard (1998), and Timothy Fagan (1986) who have elucidated the polymetamorphic and polydeformational history across the contact between the Berwick Formation (BF) and the Massabesic Gneiss Complex (MGC), southeastern New Hampshire. Together, and with the help from advanced undergraduates, their work shows that the maximum pressure of metamorphism is some 5 kbar greater in the MGC than in the BF, that M2 in the BF increases in grade toward the MGC, and that the contact is marked by abundant felsic sills in both units. With grad student Charlie Kerwin's work (1999), the MGC can now be subdivided into three distinct lithologic types. Masters theses in Vermont provide geothermobarometric and structural data for the metamorphism of mafic schist at medium to high-P facies series (Mimi Boxwell, 1986, southeastern VT; Eric Ferguson, in preparation, Worcester Mountains).
SELECTED PUBLICATIONS
Thompson, A.B. and Laird, J. (2005) Calibrations of Model Space for Metamorphism of Mafic Schist. American Mineralogist, v. 90, p 843-856.
Larson, T., Kerwin, C., Allard, S., Laird J., and Bothner, W. (1999) The metamorphic and partial tectonic history of the Massabesic Gneiss Complex and the Berwick Formation, southeastern New Hampshire. AGU Abstracts, Spring Meeting.
Larson, T.E., and Laird, J. (1998) Reaction space analysis of calc-silicate rocks visualized in three dimensions. GSA Abstracts with Programs, v. 30., no. 7, A-379.
Allard, S.T., Laird, J., and Bothner, W.A. (1998) Geothermobarometry of the pelitic members of the Upper Berwick Fm. near the Flint Hill Fault Zone, Raymond, NH. GSA Abstracts with Programs, v. 30, no. 1, p. 1.
Laird, Jo (1996) Taconian metamorphism in Vermont and Quebec: A summary. GSA Abstracts with Programs, v. 28, no. 3, p. 74.
Laird, Jo, and Kunk, M.J. (1993). 40Ar/39Ar age spectra constraints on polymetamorphism in Vermont. GSA Abstracts with Programs, v. 25, p. A102.
Laird, Jo, Trzcienski, W.E., Jr., and Bothner, W.A. (1993). High-pressure, Taconian, and subsequent polymetamorphism of southern Quebec and northern Vermont, Field Trip Guidebook for the Northeastern U.S.: 1993 Boston GSA, v. 2, p. O-1 to O-32.
Drake, A.L., Jr., Sinha, A.K., Laird, Jo, and Guy, R.E. (1989). The Taconic orogen. DNAG, v. F-2, GSA, p. 101-177.
Laird, Jo (1988). Chlorites: Metamorphic petrology, in Bailey, S.W., ed. Hydrous Phyllosilicates (exclusive of micas), MSA Reviews in Mineralogy, v. 19, p. 405-453.
Laird, Jo (1988). Pre-Arenig metamorphism in the Appalachians; Arenig to Wenlock age metamorphism in the Appalachians, in Harris. A.L., and Fettes, D.J., eds., The Caledonian-Appalachian Orogen, Geological Society Sp. Pub. no. 38, p. 141-147; p. 311-345.
Laird, Jo, Lanphere, M.A., and Albee, A.A. (1984). Distribution of Ordovician and Devonian metamorphism in mafic and pelitic schists from northern Vermont, Am. Jour. Science, v. 284, p. 376-413.
Thompson, J.B., Jr., Laird, Jo, and Thompson, A.B. (1982). Reactions in amphibolite, greenschist and blueschist. J. Petrology, v. 23, p. 1-27.