I retired from active teaching four years ago but continue to do research and work with graduate students. My principal research interests are in understanding the origin and evolution of mountain belts, particularly the northern Appalachians, by applying techniques that include metamorphic and igneous petrology, geochemistry and geochronology. Recently my efforts have concentrated on the Nashoba terrane in SE New England, an exotic fault bounded block of highly metamorphosed rocks sandwiched between rocks of lower grade. It originally formed as an arc along the edge of Gondwana at high southern latitudes in the early Paleozoic before being accreted to Laurentia in the mid-Paleozoic. Other contemporary student studies include the geochemistry of volcanic rocks in the Coastal Volcanic belt of easternmost Maine to better interpret the origin and significance of these rocks and their formation during the accretionary tectonics of the orogen. We also are using detrital zircon geochronology to help unravel the post-collisional history of the terranes in eastern New England.

• Daniel Dabrowski: Implications of Silurian granite genesis to the tectonic history of the Nashoba terrane, eastern Massachusetts (2014)
• Kristin J. Sorota: Age and origin of the Merrimack terrane, southeastern New England: A detrital zircon U-Pb geochronology study (2013)
• Andrew Kay: Sm-Nd isotope, major element, and trace element geochemistry of the Nashoba terrane, eastern Massachusetts (2012)
• MaryEllen L. Loan: New constraints on the age of deposition and provenance of the metasedimentary rocks in the Nashoba terrane, SE New England (2011)
• Tracey A. Arvin: The bedrock geology and fracture characterization of the Maynard Quadrangle of eastern Massachusetts (2010)

• Kuiper, Y.D., Thompson, M.D., Barr, S.M., White, C.E., Hepburn, J.C. and Crowley, J.L., (2017), Detrital zircon evidence for Paleoproterozic West African crust along the eastern North American continental margin, Georges Bank, offshore Massachusetts, USA.  Geology, v.45, no.9, p. 811-814, doi: 10. 1130/G39203.1
• *Kay, A., Hepburn, J.C., Kuiper, Y.D., and Baxter, E.F., (2017), Geochemical evidence for a Ganderian arc/back-arc remnant in the Nashoba terrane, SE New England, USA.  American Journal of Science, v. 317, p. 413-448, doi: 10.2475/04.2017.01
• *Valverde-Vaquero, P., Hepburn, J.C., and Martínez García, E., (2016), Geochemistry of the Upper Ordovician alkaline basalts of the Castro Fm. (Cantabrian Zone): break-up along the Ibero-Armorican margin of the Rheic Ocean?.  IX Congreso Geológico de España, Geo-Temas, v.16 (2), ISSN 1576-5172, pp. 207- 210.
• Hepburn, J.C., Kuiper, Y.D., Buchanan, J.W., *Kay, A., and *Dabrowski, D.R., (2014), Evolution of the Nashoba terrane, an early Paleozoic Ganderian arc remnant in eastern Massachusetts.  In Thompson, M.D., ed., Guidebook to Field Trips in Southeastern New England (MA-NH-RI), New England Intercollegiate Geological Conference, 106^th Annual Mtg., Wellesley, Massachusetts, p. B3-1 – B3-19.
• *Piñán Llamas, A., and Hepburn, J.C., (2013), Geochemistry of Silurian-Devonian volcanic rocks in the Coastal Volcanic belt, Machias-Eastport area, Maine: Evidence for a pre-Acadian arc.  Geological Society of America Bulletin, v. 125, no. 11-12, p. 1930-1942, doi: 10.1130/B30776.1