Faculty & Staff
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,modal space analysis, X-ray diffraction, and 40Ar/39Ar age dating of amphiboles (with the USGS and Princeton University).
PhD graduate student Ian Honsberger is studying polymetamorphism of mafic and pelitic rocks surrounding ultramafics in Stockbridge, VT (GSA abstract, v. 44, no. 2, p. 86). He joins our team of New England bedrock geologists at UNH which also includes Affiliate Professor Peter Thompson and Emeritus Professor Wally Bothner. Ian's studies have shown that high pressure metamorphism continues farther south in VT than was known, estimated P and T, and compiled our data in a modal space. This work builds on the studies of Laird and of our MS students Mimi Boxwell (1986) and Eric Ferguson (2003).
In New Hampshire masters' theses completed include those of Jeffrey Schultz (2004), 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). Together, and with the help form advanced undergraduates, their work shows that the maximum pressure of metamorphism is some 5 kbar greater in the MGC than in the BF, that the contact is marked by abundant felsic sills, the M2 in the BF increases in grade toward the MGC, and the M1 was higher grade than M2 where diopside was not stable during M2. With graduate student Charlie Kerwin's work (MS 2000, PhD 2007), the MGC can now be subdivided into three distinct lithologic type.
Selected Publication
- 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.