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Peter M Valley, Ph.D.

I have expertise in geologic mapping, igneous and metamorphic petrology, geochemistry, isotope 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.

Current Research

I am a research geologist with the Florence Bascom Geoscience Center. I am currently working on a bedrock mapping project in the northeastern Adirondack Mountains of New York. This project is part of a multidisciplinary study to understand the origin of magnetite-apatite ore deposits. Some of the deposits contain significant quantities of rare earth elements, which are considered critical minerals by the US government.

Professional Experience

  • Research Geologist, U.S. Geological Survey (Current)

  • Visiting Assistant Professor, State University of New York at Potsdam (2016–2017)

  • Sedimentologist/Petrologist, Weatherford Labs (2013-2016)

  • Field Geologist/Mapping, U.S. Geological Survey (2011-2013)

  • Field Geologist/Mapping, Geological Survey of Newfoundland and Labrador (2009-2011)

  • Research Scientist/Lab Manager, University of North Carolina at Chapel Hill (2004)

  • Adjunct Professor, Laramie County Community College (2003)

  • Research Technician, University of Wyoming (2001-2003)

  • Research Assistant, State University of New York at Buffalo (1999)

Education and Certifications

  • Ph.D. Geology, Memorial University of Newfoundland, 2011

  • M.S. Geology, University of Minnesota, 2001

  • B.S. Geology, Castelton State College, 1999

  • National Freshman Honors Society (1995)

Affiliations and Memberships*

  • American Association of Petroleum Geologists

  • Geological Association of Canada 

  • Geological Society of America 

  • Mineralogical Society of America

Honors and Awards

  • Distinction Award, PhD comprehensive exam (2005)

  • Summer Field Grant, University of Minnesota (2000)

  • Summa Cum Laude, Castleton State College (1999)

  • Presidential Scholarship Award, Castleton State College (1999)

  • Science Department Achievement Award, Castleton State College (1998)

Science and Products

Unmixing multiple metamorphic muscovite age populations with powder X-ray diffraction and 40Ar/39Ar analysis

A combination of modal estimates from powder X-ray diffraction (XRD) experiments and argon isotopic data shows that muscovite 40Ar/39Ar total gas age correlates with muscovite composition near the retrograde Bald Mountain shear zone (BMSZ) in Claremont, New Hampshire, and that the shear zone was active at ∼245 Ma. Petrologic study demonstrates that chemical disequilibrium is preserved in muscovite
Authors
Ryan J. McAleer, David Bish, Michael J. Kunk, Peter M. Valley, Gregory J. Walsh, Robert Wintsch
By
National Cooperative Geologic Mapping Program, Florence Bascom Geoscience Center

A transect through Vermont's most famous volcano - Mount Ascutney

The Cretaceous Ascutney Mountain igneous complex affords a classic exposure of the White Mountain Igneous Suite. Often called Vermont’s most famous volcano, Mount Ascutney (elev. 3,144 feet, 958 m) stands as a prominent monadnock in the Connecticut River Valley. The mountain often serves as an inspirational landmark, as it does when viewed from locations throughout the valley including the Saint-
Authors
Gregory J. Walsh, Brooks P. Proctor, Karri R. Sicard, Peter M. Valley
By
Florence Bascom Geoscience Center

Geochronology of the Oliverian Plutonic Suite and the Ammonoosuc Volcanics in the Bronson Hill arc: Western New Hampshire, USA

U-Pb zircon geochronology by sensitive high-resolution ion microprobe–reverse geometry (SHRIMP-RG) on 11 plutonic rocks and two volcanic rocks from the Bronson Hill arc in western New Hampshire yielded Early to Late Ordovician ages ranging from 475 to 445 Ma. Ages from Oliverian Plutonic Suite rocks that intrude a largely mafic lower section of the Ammonoosuc Volcanics ranged from 474.8 ± 5.2 to 4

Authors
Peter M. Valley, Gregory J. Walsh, Arthur J. Merschat, Ryan J. McAleer
By
Florence Bascom Geoscience Center, Bascom ARgon Dating (BARD) Laboratory

A transect through the base of the Bronson Hill Terrane in western New Hampshire

This trip will present the preliminary results of ongoing bedrock mapping in the North Hartland and Claremont North 7.5-minute quadrangles in western New Hampshire. The trip will travel from the Lebanon pluton to just north of the Sugar River pluton (Fig. 1) with the aim of examining the lower structural levels of the Bronson Hill anticlinorium (BHA), and the nature of the boundary with the rocks
Authors
Gregory J. Walsh, Peter M. Valley, Karri R. Sicard
By
Florence Bascom Geoscience Center

Bedrock geologic map of the Springfield 7.5- x 15-minute quadrangle, Windsor County, Vermont, and Sullivan County, New Hampshire

The bedrock geology of the 7.5- by 15-minute Springfield quadrangle consists of highly deformed and metamorphosed Mesoproterozoic through Devonian metasedimentary and meta-igneous rocks. In the west, Mesoproterozoic gneisses of the Mount Holly Complex are the oldest rocks and form the eastern side of the Chester dome. The Moretown slice structurally overlies the Chester dome along the Keyes Mounta
By
Florence Bascom Geoscience Center

Bedrock geologic map of the Mount Ascutney 7.5- x 15-minute quadrangle, Windsor County, Vermont, and Sullivan County, New Hampshire

The bedrock geology of the Mount Ascutney 7.5- x 15-minute quadrangle consists of highly deformed and metamorphosed Mesoproterozoic through Devonian metasedimentary and meta-igneous rocks intruded by rocks of the Mesozoic White Mountain Igneous Suite. In the west, Mesoproterozoic gneisses of the Mount Holly Complex are the oldest rocks and form the northeastern flank of the Chester dome. The alloc
By
Florence Bascom Geoscience Center

Science and Products

Unmixing multiple metamorphic muscovite age populations with powder X-ray diffraction and 40Ar/39Ar analysis

A combination of modal estimates from powder X-ray diffraction (XRD) experiments and argon isotopic data shows that muscovite 40Ar/39Ar total gas age correlates with muscovite composition near the retrograde Bald Mountain shear zone (BMSZ) in Claremont, New Hampshire, and that the shear zone was active at ∼245 Ma. Petrologic study demonstrates that chemical disequilibrium is preserved in muscovite
Authors
Ryan J. McAleer, David Bish, Michael J. Kunk, Peter M. Valley, Gregory J. Walsh, Robert Wintsch
By
National Cooperative Geologic Mapping Program, Florence Bascom Geoscience Center

A transect through Vermont's most famous volcano - Mount Ascutney

The Cretaceous Ascutney Mountain igneous complex affords a classic exposure of the White Mountain Igneous Suite. Often called Vermont’s most famous volcano, Mount Ascutney (elev. 3,144 feet, 958 m) stands as a prominent monadnock in the Connecticut River Valley. The mountain often serves as an inspirational landmark, as it does when viewed from locations throughout the valley including the Saint-
Authors
Gregory J. Walsh, Brooks P. Proctor, Karri R. Sicard, Peter M. Valley
By
Florence Bascom Geoscience Center

Geochronology of the Oliverian Plutonic Suite and the Ammonoosuc Volcanics in the Bronson Hill arc: Western New Hampshire, USA

U-Pb zircon geochronology by sensitive high-resolution ion microprobe–reverse geometry (SHRIMP-RG) on 11 plutonic rocks and two volcanic rocks from the Bronson Hill arc in western New Hampshire yielded Early to Late Ordovician ages ranging from 475 to 445 Ma. Ages from Oliverian Plutonic Suite rocks that intrude a largely mafic lower section of the Ammonoosuc Volcanics ranged from 474.8 ± 5.2 to 4

Authors
Peter M. Valley, Gregory J. Walsh, Arthur J. Merschat, Ryan J. McAleer
By
Florence Bascom Geoscience Center, Bascom ARgon Dating (BARD) Laboratory

A transect through the base of the Bronson Hill Terrane in western New Hampshire

This trip will present the preliminary results of ongoing bedrock mapping in the North Hartland and Claremont North 7.5-minute quadrangles in western New Hampshire. The trip will travel from the Lebanon pluton to just north of the Sugar River pluton (Fig. 1) with the aim of examining the lower structural levels of the Bronson Hill anticlinorium (BHA), and the nature of the boundary with the rocks
Authors
Gregory J. Walsh, Peter M. Valley, Karri R. Sicard
By
Florence Bascom Geoscience Center

Bedrock geologic map of the Springfield 7.5- x 15-minute quadrangle, Windsor County, Vermont, and Sullivan County, New Hampshire

The bedrock geology of the 7.5- by 15-minute Springfield quadrangle consists of highly deformed and metamorphosed Mesoproterozoic through Devonian metasedimentary and meta-igneous rocks. In the west, Mesoproterozoic gneisses of the Mount Holly Complex are the oldest rocks and form the eastern side of the Chester dome. The Moretown slice structurally overlies the Chester dome along the Keyes Mounta
By
Florence Bascom Geoscience Center

Bedrock geologic map of the Mount Ascutney 7.5- x 15-minute quadrangle, Windsor County, Vermont, and Sullivan County, New Hampshire

The bedrock geology of the Mount Ascutney 7.5- x 15-minute quadrangle consists of highly deformed and metamorphosed Mesoproterozoic through Devonian metasedimentary and meta-igneous rocks intruded by rocks of the Mesozoic White Mountain Igneous Suite. In the west, Mesoproterozoic gneisses of the Mount Holly Complex are the oldest rocks and form the northeastern flank of the Chester dome. The alloc
By
Florence Bascom Geoscience Center

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government