Gregory Walsh

I am a Project Chief and a Research Geologist with the Florence Bascom Geoscience Center. I manage bedrock geologic mapping activities for the USGS in the northeastern United States. I managed two international mapping projects in Morocco, the completion of the new bedrock geologic map of Vermont, and I conducted mapping Madagascar.

Biography

I have expertise in geologic mapping, structural geology, geochronology, tectonics, digital cartography, and GIS. I specialize in the mapping, structure, and tectonics of complexly deformed rocks, the integration of geologic data with hydrogeologic and mineral resource assessment studies, and the use of GIS as a mapping and analysis tool. I have trained students and geologists in geologic mapping, GIS, GPS, digital mapping, and U-Pb geochronology by SHRIMP. 

Awards:

  • Undergraduate Dean’s List five semesters (1982-1986)
  • Amoco Geophysics Award (1985)
  • NAGT – USGS Student Internship (1985)
  • L.R. Wilson Award, UMASS Amherst (1986)
  • Charles G. Doll Award, Vermont Geological Society (1988)
  • Seventeen USGS performance awards (1997-2018)
  • Elected GSA Fellow (2013)

Publications (excluding abstracts):

Stanley, R., Armstrong, T., Kraus, J., Walsh, G., Prewitt, J., Kimball, C., and Cua, A., 1987, The pre‑Silurian hinterland along the valleys of the White and Mad Rivers, in Westerman, D.S., editor, New England Intercollegiate Geological Conference: Guidebook for Field Trips in Vermont, v. 2, 79th Annual Meeting, Montpelier, Vermont, p. 314‑338.

Stanley, R.S., DelloRusso, V., O’Loughlin, S.B., Lapp, E.T., Armstrong, T.R., Prewitt, J.P., Kraus, J.F., and Walsh, G.J., 1987, A transect through the pre‑Silurian rocks of central Vermont, in Westerman, D.S., editor, New England Intercollegiate Geological Conference: Guidebook for Field Trips in Vermont, v. 2, 79th Annual Meeting, Montpelier, Vermont, p. 272‑295.

Walsh, G.J., and Kimball, C.V., 1989, Geochemistry of the metabasic rocks from the pre‑Silurian rift‑clastic sequence of central Vermont, in Colpron, M., and Doolan, B., editors, Proceedings of the Quebec‑Vermont Appalachian Workshop, University of Vermont, Burlington, Vermont, p. 74‑76.

Walsh, G.J., 1992, Bedrock geology of the Fayston – Buels Gore area central Vermont: Vermont Geological Survey Special Bulletin No. 13, 74 p., scale 1:24,000, http://www.anr.state.vt.us/dec/geo/specbulls.htm.

Ross, D.S., Bartlett, R.J., Magdoff, F.R., and Walsh, G.J., 1994, Flow path studies in forested watersheds of headwater tributaries of Brush Brook, Vermont: Water Resources Research, v. 30, no. 9, p. 2611‑2618, doi:10.1029/94WR01490.

Walsh, G.J., and Ratcliffe, N.M., 1994, Preliminary bedrock geologic map of the Plymouth quadrangle and eastern portion of the Killington Peak quadrangle, Windsor and Rutland Counties, Vermont: U.S. Geological Survey Open‑File Report 94‑225, 36 p., scale 1:24,000, http://pubs.er.usgs.gov/publication/ofr94225A.

Walsh, G.J., Ratcliffe, N.M., Dudley, J.B., and Merrifield, T., 1994, Digital bedrock geologic map of the Mount Holly and Ludlow quadrangles, Vermont and explanation of the bedrock geology database in the Vermont Geographic Information System: U.S. Geological Survey Open‑File Report 94‑229, scale1:24,000, http://ngmdb.usgs.gov/Prodesc/proddesc_12480.htm.

Walsh, G.J., and Ratcliffe, N.M., 1994, Digital bedrock geologic map of the Plymouth quadrangle, Vermont: U.S. Geological Survey Open‑File Report 94‑654, scale 1:24,000, http://ngmdb.usgs.gov/Prodesc/proddesc_18567.htm.

Walsh, G.J., and Falta, C.K., 1996, Preliminary bedrock geologic map of the Rochester quadrangle, Rutland, Windsor, and Addison Counties, Vermont: U.S. Geological Survey Open‑File Report 96‑25, scale 1:24,000, http://pubs.er.usgs.gov/publication/ofr9625.

Walsh, G.J., and Falta, C.K., 1996, Digital bedrock geologic map of the Rochester quadrangle, Vermont: U.S. Geological Survey Open‑File Report 96‑33, scale 1:24,000, http://ngmdb.usgs.gov/Prodesc/proddesc_43379.htm.

Walsh, G.J., Armstrong, T.R., and Ratcliffe, N.M., 1996, Preliminary bedrock geologic map of the Vermont part of the 7.5 x 15 minute Mount Ascutney and Springfield quadrangles, Windsor County, Vermont: U.S. Geological Survey Open‑File Report 96‑719, 38 p., scale 1:24,000, http://pubs.usgs.gov/of/1996/719/.

Walsh, G.J., Armstrong, T.R., and Ratcliffe, N.M., 1996, Digital bedrock geologic map of the Vermont part of the 7.5 x 15 minute Mount Ascutney and Springfield quadrangles, Vermont: U.S. Geological Survey Open‑File Report 96‑733, scale 1:24,000, http://ngmdb.usgs.gov/Prodesc/proddesc_18694.htm.

Armstrong, T.R., Walsh, G.J., and Spear, F.S., 1997, A transect across the Connecticut valley sequence in east‑central Vermont: in Grover, T.W., Mango, H.N., and Hasenohr, E.J., editors, New England Intercollegiate Geological Conference: Guidebook to Field Trips in Vermont and adjacent New Hampshire and New York, 89th Annual Meeting, Castleton, Vermont, p. A6: 1‑56.

Ratcliffe, N.M., Walsh, G.J., and Aleinikoff, J., 1997, Basement, metasedimentary and tectonic cover of the Green Mountain massif and western flank of the Chester dome, in Grover, T.W., Mango, H.N., and Hasenohr, E.J., editors, New England Intercollegiate Geological Conference: Guidebook to Field Trips in Vermont and adjacent New Hampshire and New York, 89th Annual Meeting, Castleton, Vermont, p. C6: 1‑54.

Walsh, G.J., 1998, Digital bedrock geologic map of the Vermont part of the Hartland quadrangle, Windsor County, Vermont: U.S. Geological Survey Open‑File Report 98‑123, 17 p., scale 1:24,000, http://pubs.usgs.gov/of/1998/0123a/report.pdf , http://ngmdb.usgs.gov/Prodesc/proddesc_17764.htm

Ratcliffe, N.M., and Walsh, G. J., 1998, Digital and preliminary bedrock geologic map of the Mount Carmel quadrangle, Vermont: U.S. Geological Survey Open‑File Report 98‑330, scale 1:24,000, http://ngmdb.usgs.gov/Prodesc/proddesc_17795.htm.

Walsh, G. J., and Ratcliffe, N.M., 1998, Digital and preliminary bedrock geologic map of the Pico Peak quadrangle, Vermont: U.S. Geological Survey Open‑File Report 98‑226, scale 1:24,000, http://ngmdb.usgs.gov/Prodesc/proddesc_17784.htm.

Walsh, G.J., and Clark, S.F., Jr., 1999, Bedrock geologic map of the Windham quadrangle, Rockingham and Hillsborough Counties, New Hampshire, U.S. Geological Survey Open‑File Report 99‑8, 18 p., scale 1:24,000, http://pubs.usgs.gov/of/of99-8/.

Walsh, G.J., and Aleinikoff, J.N., 1999, U-Pb zircon age of metafelsite from the Pinney Hollow Formation: Implications for the development of the Vermont Appalachians: American Journal of Science, v. 299, p. 157-170, doi: 10.2475/ajs.299.2.157

Ratcliffe, N.M., Harris, A.G., and Walsh, G.J., 1999, Tectonic and regional metamorphic implications of the discovery of Middle Ordovician conodonts in cover rocks east of the Green Mountain massif, Vermont: Canadian Journal of Earth Sciences, v. 36, no. 3, p. 371-382, doi: 10.1139/e99-009.

Walsh, G.J., Reddy, J.E., and Armstrong, T.R., 1999, Geologic mapping and collection of geologic structure data with a GPS receiver and a Personal Digital Assistance (PDA) computer, in Soller, D.R., editor, Digital Mapping Techniques ‘99 – Workshop Proceedings: U.S. Geological Survey Open-File Report 99-386, p. 127-131, http://pubs.usgs.gov/openfile/of99-386/walsh.html.

Burton, W.C., Armstrong, T.R., and Walsh, G.J., 1999, Bedrock geologic framework of the Mirror Lake research site, New Hampshire, in Morganwalp, D.W., and Buxton, H.T., editors, U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, 1999--Volume 3 of 3--Subsurface Contamination from Point Sources: U.S. Geological Survey Water-Resources Investigations Report 99-4018C, p. 705-714, http://toxics.usgs.gov/pubs/wri99-4018/Volume3/SectionG/3805_Burton/index.html.

Walsh, G.J. and Clark, S.F., Jr., 2000, Contrasting methods of fracture trend characterization in crystalline metamorphic and igneous rocks of the Windham quadrangle, New Hampshire: Northeastern Geology and Environmental Sciences, v. 22, no. 2, p. 109-120.

Burton, W.C., Walsh, G.J., and Armstrong, T.R., 2000, Bedrock geologic map of the Hubbard Brook Experimental Forest, Grafton County, New Hampshire: U.S. Geological Survey Open-File Report 00-45, 2 plates, 25 p., scale 1:10,000. http://pubs.usgs.gov/openfile/of00-045/.

Walsh, G.J., and Falta, C.K., 2001, Bedrock geologic map of the Rochester quadrangle, Rutland, Windsor, and Addison Counties, Vermont: U.S. Geological Survey Geologic Investigations Series Map I‑2626, 14 p., scale 1:24,000, http://pubs.er.usgs.gov/publication/i2626.

Walsh, G.J., 2001, Bedrock geology in the vicinity of the Knowles and Andreas well sites, West Newbury, Massachusetts:  U.S. Geological Survey Open-File Report 01-353, 14 p., http://pubs.usgs.gov/of/2001/of01-353/.

Walsh, G.J., 2001, Bedrock geology in the vicinity of the Rockland Avenue well site, Maynard, Massachusetts: U.S. Geological Survey Open-File Report 01-354, 15 p., http://pubs.usgs.gov/of/2001/of01-354/.

Walsh, G.J., 2002, Bedrock geology in the vicinity of the Leicester well site, Paxton, Massachusetts: U.S. Geological Survey Open-File Report 02-433, 19 p., http://pubs.usgs.gov/of/2002/of02-433/.

Walsh, G.J., Aleinikoff, J.N., Benziane, F., Yazidi, A., and Armstrong, T.R., 2002, U-Pb zircon geochronology of the Paleoproterozic Tagragra de Tata inlier and its Neoproterozoic cover, western Anti-Atlas, Morocco: Precambrian Research, v. 117, p. 1-20, doi: 10.1016/S0301-9268(02)00044-X.

Moore, R. B., Schwarz, G. E., Clark, S. F., Jr., Walsh, G. J., and Degnan, J. R., 2002, Factors related to well yield in the fractured bedrock aquifer of New Hampshire: U.S. Geological Survey Professional Paper 1660, 51 p, http://water.usgs.gov/pubs/pp/pp1660/.

Benziane, F., Yazidi, A., Walsh, G.J., Armstrong, T.R., Kouhen, M.A., Yazidi, M., Khamlichi, M.A., and Aleinikoff, J.N., 2002, Carte géologique au 1/50 000, Feuille Afouzar: Notes et Mémoires Service Géologique du Maroc No. 422, 71 p.

Yazidi, A., Benziane, F., Walsh, G.J., Armstrong, T.R., Kouhen, M.A., Yazidi, M., and Khamlichi, M.A., 2002, Carte géologique au 1/50 000, Feuille Zawyat Si Nisser: Notes et Mémoires Service Géologique du Maroc No. 423, 69 p.

Walsh, G.J., 2003, Bedrock geologic map of the New Milford quadrangle, Litchfield and Fairfield Counties Connecticut: U.S. Geological Survey Open-File Report 03-487, 49 p., scale 1:24,000, http://pubs.usgs.gov/of/2003/of03-487/.

Walsh, G.J., Aleinikoff, J.N., and Fanning, C.M., 2004, U-Pb geochronology and evolution of Mesoproterozoic basement rocks, western Connecticut, in Tollo, R.P., Corriveau, L., McLelland, J.M., and Bartholomew, M.J., editors, Proterozoic Tectonic Evolution of the Grenville Orogen in North America:  Boulder, Colorado, Geological Society of America Memoir No.197, p. 729-753, doi: 10.1130/0-8137-1197-5.729.

Walsh, G.J., 2005, Bedrock geology of the New Milford quadrangle, Connecticut, in McHone, N.W., and Peterson, M.J., editors, New England Intercollegiate Geological Conference: Guidebook for Field Trips in Connecticut, 97th Annual Meeting, New Haven, Connecticut, Trip B5, p. 191-203.

Walsh, G.J., and Satkoski, A.M., 2005, Surface gamma-ray survey of the Barre West quadrangle, Washington and Orange Counties, Vermont: U.S. Geological Survey Scientific Investigations Report 2005-5276, 19 p., http://pubs.usgs.gov/sir/2005/5276/.

Walsh, G. J., Scott, R. B., Aleinikoff, J. N., and Armstrong, T. R., 2006, Preliminary bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut: U.S. Geological Survey Open File Report 2006-1296, scale 1:24,000, http://pubs.usgs.gov/of/2006/1296/.

Walsh, G.J., Aleinikoff, J.N., and Wintsch, R.P., 2007, Origin of the Lyme dome and implications for the timing of multiple Alleghanian deformational and intrusive events in southern Connecticut: American Journal of Science, v. 307, no. 1, p. 168-215, doi: 10.2475/06.2007.06.

Wintsch, R.P., Aleinikoff, J.N., Walsh, G.J., Bothner, W.A., Hussey, A.M., and Fanning, C.M., 2007, SHRIMP U-Pb evidence for a Late Silurian age of metasedimentary rocks in the Merrimack and Putnam-Nashoba terranes, eastern New England: American Journal of Science, v. 307, no. 1, p. 119-167, doi: 10.2475/01.2007.05.

Shapiro, A. M.,  Hsieh, P.A., Burton, W.C., and Walsh, G.J., 2007, Integrated multi-scale characterization of ground-water flow and chemical transport in fractured crystalline rock at the Mirror Lake site, New Hampshire, in Subsurface Hydrology: Data Integration for Properties and Processes, D. W. Hyndman,  F. D. Day-Lewis, and K. Singha, editors, Geophysical Monograph Series, vol. 171, p. 201-226, AGU, Washington, D.C., http://www.agu.org/books/gm/v171/.

Pierce, H.A., Walsh, G.J., Burruss, R.C., and Degnan, J.R., 2007, Borehole characterization of a methane-yielding bedrock well, Tyngsborough, Massachusetts: U.S. Geological Survey Open-File Report 2007-1399, http://pubs.usgs.gov/of/2007/of2007-1399.

Degnan, J.R., Walsh, G.J., Flanagan, Sarah, and Burruss, R.C., 2008, Bedrock, borehole, and water-quality characterization of a methane-producing water well in Wolfeboro, New Hampshire: U.S. Geological Survey Open-File Report 2008–1333, 47 p., http://pubs.usgs.gov/of/2008/1333.

Stone B.D., Benziane F., El Fahssi A., Yazidi A., Walsh G.J., Yazidi M., Saadane A., Ejjaouani H., and Kalai M., 2008, Carte géologique au 1/50 000, Feuille Sidi Flah: Notes et Mémoires du Service Géologique du Maroc No. 467, 113 p.

Benziane F., Yazidi A., Saadane A., Yazidi M., El Fahssi A., Stone B.D., Walsh G.J., Burton W.C., Aleinikoff J.N., Ejjaouani H., and Kalai M., 2008, Carte géologique au 1/50 000, Feuille Qal'at Mgouna: Notes et Mémoires Service Géologique du Maroc No. 468, 139 p.

Walsh G.J., Benziane F., Burton W.C., El Fahssi A., Yazidi A., Yazidi M., Saadane A., Aleinikoff J.N., Ejjaouani H., Harrison R.W., Stone B.D., and Kalai M., 2008, Carte géologique au 1/50 000, Feuille Bouskour: Notes et Mémoires Service Géologique du Maroc No. 469, 131 p.

Harrison R.W., Yazidi A., Benziane F., Quick J.E., El Fahssi A., Stone B.D., Yazidi M., Saadane A., Walsh G.J., Aleinikoff J.N., Ejjaouani H., and Kalai M., 2008, Carte géologique au 1/50 000, Feuille Tizgui: Notes et Mémoires Service Géologique du Maroc No. 470, 131 p.

Walsh G.J., Yazidi A., Benziane F., Burton W.C., El Fahssi A., Stone B.D., Yazidi M., Saadane A., Aleinikoff J.N., Ejjaouani H., and Kalai M., 2008,  Carte géologique au 1/50 000, Feuille Timdghas: Notes et Mémoires Service Géologique du Maroc No. 471,  107 p.

Yazidi A., Benziane F., Walsh G.J., Harrison R.W., Saadane A., Yazidi M., Quick J.E., El Fahssi A., Stone B.D., Aleinikoff J.N., Ejjaouani H., and Kalai M., 2008, Carte géologique au 1/50 000, Feuille Ait Semgane: Notes et Mémoires Service Géologique du Maroc No. 472, 113 p.

Walsh, G., Lidke, D., Bauer, W., Goodenough, K.M., De Waele, B., and Thomas, R.J., 2008, Carte géologique de Madagascar, Feuille XY36 Maroambihy: Série de Carte Géologique echelle 1:100,000, Ministère de l’Énergie et des Mines, Projet de Gouvernance des Ressources Minérales, Antananarivo.

Bauer, W., Walsh, G., and Lidke, D., 2008, Carte géologique de Madagascar, Feuille X37 Sarahandrano: Série de Carte Géologique echelle 1:100,000, Ministère de l’Énergie et des Mines, Projet de Gouvernance des Ressources Minérales, Antananarivo.

Lidke, D., Bauer, W., De Waele, B., and Walsh, G. , 2008, Carte géologique de Madagascar, Feuille  XY37 Antalaha/Ambohibe: Série de Carte Géologique echelle 1:100,000, Ministère de l’Énergie et des Mines, Projet de Gouvernance des Ressources Minérales, Antananarivo.

Thomas, R.J., De Waele, B., Schofield, D.I., Goodenough, K.M., Horstwood, M., Tucker, R., Bauer, W., Annells, R., Howard, K., Walsh, G., Rabarimanana, M.,  Rafahatelo, J.M., Ralison, V., and Randriamananjara, T., 2009, Geological Evolution of the Neoproterozoic Bemarivo Belt, northern Madagascar: Precambrian Research, v. 172, p. 279-300, doi:10.1016/j.precamres.2009.04.008.

Walsh, G.J., Scott, R.B., Aleinikoff, J.N., and Armstrong, T.R., 2009, Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut: U.S. Geological Survey Scientific Investigations Map 3052, 2 sheets, scale 1:24,000, 29-p. text, http://pubs.usgs.gov/sim/3052/.

Walsh, G.J., 2009, A method for creating a three dimensional model from published geologic maps and cross sections: U.S. Geological Survey Open-File Report 2009–1229, 16 p., http://pubs.usgs.gov/of/2009/1229/.

Kim, Jonathan, Gale, Marjorie, Coish, Ray, Laird, Jo, and Walsh, Greg, 2009, Road to the Kingdom: A bedrock transect across the Pre-Silurian Rowe-Hawley Belt in central Vermont, in Westerman, D., and Lathrop, A., editors, Guidebook for Field Trips in the Northeast Kingdom of Vermont and Adjacent Regions: New England Intercollegiate Geological Conference, 101st Annual Meeting, Lyndonville, Vermont, Trip B2, p. 95-120.

Walsh, G.J., Kim, J., and Gale, M.H., 2009, Bedrock geology of the Montpelier area, Central Vermont, in Westerman, D., and Lathrop, A., editors, Guidebook for Field Trips in the Northeast Kingdom of Vermont and Adjacent Regions: New England Intercollegiate Geological Conference, 101st Annual Meeting, Lyndonville, Vermont, Trip C4, p. 243-260.

McWilliams, C.K., Walsh, G.J., and Wintsch, R.P., 2010, Silurian-Devonian age and tectonic setting of the Connecticut Valley-Gaspé trough of Vermont using U-Pb SHRIMP analyses of detrital zircons: American Journal of Science, v. 310, p. 325-363, doi: 10.2475/05.2010.01.

Walsh, G.J., Kim, Jon, Gale, M.H., and King, S.M., 2010, Bedrock geologic map of the Montpelier and Barre West quadrangles, Washington and Orange Counties, Vermont: U.S. Geological Survey Scientific Investigations Map 3111, scale 1:24,000, 36-p. text, http://pubs.usgs.gov/sim/3111/.

Schofield, D.I., Thomas, R.J., Goodenough, K.M., De Waele, B., Pitfield, P.E.J., Key, R.M., Bauer, W., Walsh, G.J., Lidke, D.J., Ralison, A.V., Rabarimanana, M., Rafahatelo, J .M., and Randriamananjara, T., 2010, Geological evolution of the Antongil Craton, NE Madagascar, Precambrian Research, v. 182, p. 187-203, doi:10.1016/j.precamres.2010.07.006.

Bauer, Wilfried, Walsh G.J., deWaele, Bert, Thomas, R.J., Horstwood, M.S.A., Bracciali, Laura, Schofield, D.I., Wollenberg, Uwe, Lidke, D.I., Rasaona, I.T., and Rabarimanana, M.H., 2011, Cover sequences at the northern margin of the Antongil Craton, NE Madagascar: Precambrian Research, v. 189, p. 292-312, doi: 10.1016/j.precamres.2011.07.018.

Walsh, G.J., Ratcliffe, N.M., and Kunk, M.J., 2011, A transect across the basement massifs of the central Green Mountains, Vermont, in West, D.P., Jr., editor, Guidebook for Field Trips in Vermont and adjacent New York: New England Intercollegiate Geological Conference, 103rd Annual Meeting, Middlebury, Vermont, Trip B3, p. B3-1 – B3-14.

Ratcliffe, N.M., Kunk, M.J., Burton, W.C., and Walsh, G.J., 2011, Traverse of the major fault systems of the Taconian deformational front, the Vermont Valley and core of the Green Mountain massif, southern Vermont, in West, D.P., Jr., editor, Guidebook for Field Trips in Vermont and adjacent New York: New England Intercollegiate Geological Conference, 103rd Annual Meeting, Middlebury, Vermont, Trip A3, p. A3-1 – A3-35.

Key, R.M., Pitfield, P.E.J., Thomas, R.J., Goodenough, K.M., De Waele, B., Schofield, D.I., Bauer, W., Horstwood, M.S.A., Styles, M.T., Conrad, J., Encarnacion, J., Lidke, D.J., O’Connor, E.A., Potter, C., Smith, R.A., Walsh, G.J., Ralison, A.V., Randriamananjara, T., Rafahatelo, J.-M., and Rabarimanana, M., 2011, Polyphase Neoproterozoic orogenesis within the East Africa–Antarctica Orogenic Belt in central and northern Madagascar, D.J.J. van Hinsbergen, S.J.H. Buiter, T.H. Torsvik, C. Gaina and S. Webb, editors, The Formation and Evolution of Africa: A Synopsis of 3.8 Ga of Earth History: Geological Society of London, Special Publications, v. 357, p. 49-68, doi: 10.1144/​SP357.4.

Aleinikoff, J.N., Ratcliffe, N.M., and Walsh, G.J., 2011, Provisional zircon and monazite uranium-lead geochronology for selected rocks from Vermont: U.S. Geological Survey Open-File Report 2011-1309, 46 p., http://pubs.usgs.gov/of/2011/1309/.

Ratcliffe, N.M., Stanley, R.S., Gale, M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, scale 1:100,000, http://pubs.usgs.gov/sim/3184/.

Walsh, G.J., Aleinikoff, J.N., and Dorais, M.J., 2011, Bedrock geologic map of the Grafton quadrangle, Worcester County, Massachusetts: U.S. Geological Survey Scientific Investigations Map 3171, scale 1:24,000, http://pubs.usgs.gov/sim/3171/.

Walsh, G.J., Aleinikoff, J.N. and Wintsch, R.P., 2012, Unraveling Alleghanian orogenesis in southern Connecticut; the history of the Lyme dome, in Thomas, M.A., editor, Guidebook for Fieldtrips in Connecticut and Massachusetts: Northeast Section Geological Society of America Meeting 2012, State Geological and Natural History Survey of Connecticut, Guidebook Number 9, p. D1-D16.

Walsh, G.J., Benziane, F., Aleinikoff, J.N., Harrison, R.W., Yazidi, A., Burton, W.C., Quick, J.E., and Saadane, A., 2012, Neoproterozoic tectonic evolution of the Jebel Saghro and Bou Azzer – El Graara inliers, eastern and central Anti-Atlas, Morocco: Precambrian Research, v. 216-219, p. 23-62, http://dx.doi.org/10.1016/j.precamres.2012.06.010.

Walsh, G.J., Valley, P.M., and Sicard, K.R., 2012, A transect through the base of the Bronson Hill anticlinorium in western New Hampshire, in Thompson, P.J., and Thompson, T.B., editors, Guidebook to field trips in western New Hampshire and adjacent Vermont and Massachusetts, 104th New England Intercollegiate Geological Conference, Mount Sunapee, New Hampshire, p. A4-1 - A4-21.

Walsh, G.J., Jahns, R.H., and Aleinikoff, J.N., 2013, Bedrock geologic map of the Nashua South quadrangle, Hillsborough County, New Hampshire and Middlesex County, Massachusetts: U.S. Geological Survey Scientific Investigations Map 3200, scale 1:24,000, 31-p. pamphlet, http://pubs.usgs.gov/sim/3200/

Benoît, N., Lavoie, D., Walsh, G., Rivard, C., and Huot-Vézina, G., 2013, Bedrock geology, Richelieu-Lake Champlain and Yamaska watersheds, Québec, New York and Vermont/ Géologie du socle rocheux, bassins Richelieu-Lac Champlain et Yamaska, Québec, New York et Vermont: Geological Survey of Canada, Open File 7283, scale 1:250,000, doi: 10.4095/292441

Growdon, M.L., Kunk, M.J., Wintsch, R.P., and Walsh, G.J., 2013, Telescoping metamorphic isograds: Evidence from 40Ar/39Ar dating in the Orange-Milford Belt, southern Connecticut: American Journal of Science, v. 313, no. 10, p. 1017-1053, doi:10.2475/10.2013.03

Walsh, G.J., 2014, Bedrock geology of the New Milford quadrangle, Connecticut, in Stone, J.R., and Thomas, M.A., editors, Geological Society of Connecticut Fieldtrip Guidebook No. 5, Fifth Annual Fieldtrip, Geological Society of Connecticut & Connecticut Department of Energy and Environmental Protection, 18 p.

Walsh, G.J., 2014, Bedrock geologic map of the Uxbridge quadrangle, Worcester County, Massachusetts, and Providence County, Rhode Island: U.S. Geological Survey Scientific Investigations Map 3295, 1 sheet, scale 1:24,000, 36-p. pamphlet, http://dx.doi.org/10.3133/sim3295

Álvaro, J.J., Benziane, Fouad, Thomas, Robert, Walsh, G.J., and Yazidi, Abdelaziz, 2014, Neoproterozoic–Cambrian stratigraphic framework of the Anti-Atlas and Ouzellagh promontory (High Atlas), Morocco: Journal of African Earth Sciences, v. 98, p. 19-33, http://dx.doi.org/10.1016/j.jafrearsci.2014.04.026

Kopera, J.P., and Walsh, G.J., 2014, The eastern Merrimack terrane in Massachusetts: Revisiting metamorphism, deformation and plutonism, in Thompson, Margaret D., editor, Guidebook to Field Trips in Southeastern New England (MA-NH-RI): 106th New England Intercollegiate Geological Conference, Wellesley, Massachusetts, p. A3-1 - A3-20.

Walsh, G.J., and Merschat, A.J., 2015, Bedrock geologic map of the Worcester South quadrangle, Worcester County, Massachusetts: U.S. Geological Survey Scientific Investigations Map 3345, 1 sheet, scale 1:24,000, http://dx.doi.org/10.3133/sim3345

Regan, S.P., Geer, P.S. Walsh, G.J., Aleinikoff, J.N., Baird, G.B., Valley, P.M., Williams, M.L. Jercinovic, M.J., and Grover, T.W., 2015, Precambrian geology of the Eagle Lake quadrangle, Essex County, New York, in Franzi, David, editor, Geology of the Northeastern Adirondack Mountains and Champlain – St. Lawrence Lowlands of New York, Vermont and Quebec, New York State Geological Association, 87th Annual Meeting, State University of New York at Plattsburgh, Plattsburgh, NY, p. 30-59.

Coish, Raymond, Kim, Jon, Twelker, Evan, Zolkos, Scott, and Walsh, Gregory, 2015, Geochemistry and origin of metamorphosed mafic rocks from the Lower Paleozoic Moretown and Cram Hill Formations of north‐central Vermont: Delamination magmatism in the western New England Appalachians: American Journal of Science, v. 315, p. 809-845, http://dx.doi.org/ 10.2475/09.2015.02  

Degnan, J.R., Bohlke, J.K., Pelham, Krystle, Langlais, D.M., Walsh, G.J., 2016, Identification of groundwater nitrate contamination from explosives used in road construction: Isotopic, chemical, and hydrologic evidence: Environmental Science & Technology, v. 50, p. 593-603, http://dx.doi.org/10.1021/acs.est.5b03671

Walsh, G.J., 2016, Bedrock geologic map of the Hartland and North Hartland quadrangles, Windsor County, Vermont, and Sullivan and Grafton Counties, New Hampshire: U.S. Geological Survey Scientific Investigations Map 3361, 2 sheets, scale 1:24,000, http://dx.doi.org/10.3133/sim3361.

McAleer, R.M., Bish, D.L., Kunk, M.J., Sicard, K.R., Valley, P.M., Walsh, G.J., Wathen, B.A., and Wintsch, R.P., 2016, Reaction softening by dissolution-precipitation creep in a retrograde greenschist-facies ductile shear zone, New Hampshire, USA: Journal of Metamorphic Geology, v. 35, no. 1, p. 95-119, doi:10.1111/jmg.12222

Walsh, G.J., 2017, A transect through Vermont’s most famous volcano – Mount Ascutney: Geological Survey of New Hampshire, Granite State Geologist, September 2017, no. 98, 4 p.,http://www.gsnh.org/uploads/9/2/8/6/92861090/gsnh_mnt_ascutney_summer_20...

Taylor, R.D., Taylor, C.D., Walsh, G.J., and Shah, A.K., 2017, Apatite textures and REE chemistry from the iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, USA: SGA Mineral Resources to Discover, SGA 2017 Proceedings, Society for Geology Applied to Mineral Deposits, v. 3, p. 891-894.

Taylor, R.D., Taylor, C.D., Walsh, G.J., and Shah, A.K., 2018, Geochemistry of ore, host rock, and mine waste pile samples of iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, in relation to potential rare earth elements resources, 2016-2018: U.S. Geological Survey Data Release, https://doi.org/10.5066/P9EEXCKI

Dicken, C.L., Horton, J.D., San Juan, C.A., Anderson, A.K., Ayuso, R.A., Bern, C.R., Bookstrom, A.A., Bradley, D.C., Bultman, M.W., Carter, M.W., Cossette, P.M., Day, W.C., Drenth, B.J., Emsbo, P., Foley, N.K., Frost, T.P., Gettings, M.E., Hammarstrom, J.M., Hayes, T.S., Hofstra, A.H., Hubbard, B.E., John, D.A., Jones, J.V.,III, Kreiner, D.C., Lund, K., McCafferty, A.E., Merchat, A.J., Ponce, D.A., Schulz, K.J., Shah, A.K., Siler, D.L., Taylor, R.D., Vikre, P.G., Walsh, G.J., Woodruff, L.G., and Zurcher, L., 2019, GIS and data tables for focus areas for potential domestic nonfuel sources of rare earth elements: U.S. Geological Survey data release, https://doi.org/10.5066/P95CHIL0

Shah, A.K., Walsh, G.J., Klein, A.J., and Suarez, K.A., 2019, Petrophysical data collected on outcrops and rock samples from the eastern Adirondack Highlands, New York: U.S. Geological Survey data release, https://doi.org/10.5066/P9E6P7S2

Regan, S.P., Walsh, G.J., Williams, M.L., Chiarenzelli, J.R., Toft, M., and McAleer, R., 2019, Syn-collisional exhumation of hot middle crust in the Adirondack Mountains (New York, USA): Implications for extensional orogenesis in the southern Grenville Province: Geosphere, v. 15, p. 1-22, https://doi.org/10.1130/GES02029.1