John Valley

Research

My research interests span many fields in Earth Science, including:

• The igneous and metamorphic evolution of the crust during orogenesis with emphasis on the role of magmas, fluids, and thermobarometry.
• Precambrian geology and Early Earth
• Silicate and carbonate diagenesis.
• The rock record of past climate.
• Astrobiology.
• Mineralogy & gemology.
• New technology for microanalysis of stable isotope ratios.

Projects generally stress an integrated approach to field-oriented studies, combining isotope geochemistry and mineral chemistry.

Many of these projects have involved use of laboratories for advanced geochemical
analysis in the Department of Geoscience, UW-Madison including:

• Stable Isotope Lab
• Electron Microprobe and SEM
• Radiogenic Isotope Lab
• CAMECA 1280 Ion Microprobe.

Recent graduate theses include:

• Cephalopod ecology inferred from SIMS analyses of stable isotopes (Ben Linzmeier PhD 2017)
• Oxygen isotope thermometry in emery, Naxos, Greece (Rachelle Turnier MS 2017)
• Quartz-inclusion thermometry in Hadean zircons (Emma Cameron MS 2017)
• Carbonate diagenesis in sandstone, Illinois basin (Adam Denny MS 2016)
• Polyphase history of the 3.4 Ga Strelley Pool Chert (Jake Cammack MS 2015)
• Isotope zoning in titanite: Rapid cooling and uplift in the Grenville (Chloe Bonamici PhD 2013).
• Diagenesis and fluid flow, Illinois basin (Anthony Pollington PhD 2013).
• Genesis of low d¹⁸O rhyolites, Snake River Plain (Tyler Blum MS 2013).
• Isotope zoning in eclogite facies garnets (Ashley Russell MS 2012).
• Oxygen isotope study of daily depth migration of nautiloids (Ben Linzmeier MS 2012).
• Seasonality in Holocene Climate, Speleothems From Soreq Cave Israel (Ian Orland, MS 2008; PhD 2012).
• Oxygen isotope geochemistry, dinkey dome Pluton, Sierra Nevada (Raiza Quintero, MS 2011).
• Mineral inclusions in zircon, Hadean to present (Dayi Ortiz, MS 2010).
• Migmatites in the Adirondacks (Penny Lancaster, MS 2007).
• Analysis of oxygen isotope ratios in quartz overgrowths in St. Peter Sandstone,migration of basin brines and the genesis of MVT-type Pb-Zn ore deposits (Jacque Kelly, MS 2006).
• Oxygen isotope geochemistry of the Sierra Nevada batholith: magmatic source,  wall rock contamination, cooling history (JS Lackey, PhD 2005).
• 4.4-4.0 Ga, Early Archean detrital zircons, Jack Hills, W. Australia, U-Pb
  and O isotopes, oceans on Early Earth (Aaron Cavosie, PhD 2005).
• Origin of subduction-related silicic magmas, Nicaragua and Costa Rica (Jake
  Eaton, MS 2004).
• Contact metamorphism of the Biwabik Fe Formation, MN, oxygen isotope speedometry.
  (Beth Valaas MS 2004).
• Carbon isotope thermometry in granulite facies marbles, Salinian Block,
  CA (Joyashish Thakurta, MS 2003).
• Source and alteration of granitic magmas, western US (Liz King PhD, 2001).
• Genesis of polymetamorphosed skarns, Marcy Anorthosite Massif, Adirondack
  Mts, NY (Cory Clechenko, MS 2001).
• Fluid flow and formation of wollastonite skarns, Mt. Morrison Pendant, CA
  (JS Lackey, MS 2000).
• Crustal input to anorthosite magmas, Grenville Province, Quebec and NY (William
  Peck, PhD 2000).

Teaching

I teach a variety of courses including Physical Geology, Principles of Mineralogy, Elementary Petrology, Advanced Metamorphic Petrology, and Seminars in Stable Isotope Geochemistry, Metamorphic Petrology, and Astrobiology.

Professional Responsibilities

• Gemological Institute of America, Board of Governors 2014-
• Elements: Senior Editor, 2011-2015
• Mineralogical Society of America: President 2005-06
• American Journal of Science: Associate Editor, 1996-
• Geochemical Society: Program Committee, 1988-91
• Associate Editor, G.S.A. Bulletin, 1985-91