J. W. Valley

J. W. Valley
University of Wisconsin–Madison | UW · Department of Geoscience

PhD

About

804
Publications
114,286
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35,363
Citations
Additional affiliations
June 1983 - present
University of Wisconsin–Madison
Position
  • Professor
Description
  • valley@geology.wisc.edu

Publications

Publications (804)
Article
The Ediacaran Shuram excursion (SE) records a global decrease in carbonate carbon isotope (δ¹³Ccarb) values from +6‰ down to ca. –10‰, representing the largest δ¹³Ccarb negative anomaly in Earth history. While the SE is widely recorded in the upper Doushantuo Formation of South China, it shows highly variable δ¹³Ccarb profiles among correlative sec...
Article
Full-text available
Infiltration-driven metamorphism has produced the widespread development of forsterite in the siliceous dolomites of the Alta, Utah contact aureole. SIMS (secondary ion mass spectrometry) δ¹⁸O analyses show that in most of the middle to outer forsterite zone samples, forsterite, calcite and dolomite are homogenous in δ¹⁸O at the grain-scale, but fo...
Article
The instrumental bias (here expressed as bias*, the difference relative to San Carlos Olivine, SC-Ol) of oxygen isotopes in secondary ion mass spectrometry (SIMS) analyses of olivine and pyroxene were investigated. Seventeen olivine (Fo0–100), nine orthopyroxene (En70–100Wo0–3), and three clinopyroxene (En28-49Wo45–50) reference materials (RMs) wer...
Article
Full-text available
Significance There is a common consensus that lode gold deposits mostly precipitated from metamorphic fluids via fluid boiling and/or fluid–rock interaction, but whether magmatic hydrothermal fluids and the mixing of such fluids with an external component have played a vital role in the formation of lode gold deposits remains elusive. We use garnet...
Article
Full-text available
The nature of Earth's earliest crust and crustal processes remain unresolved questions in Precambrian geology. While some hypotheses suggest that plate tectonics began in the Hadean, others suggest that the Hadean was characterized by long‐lived protocrust and an absence of significant plate tectonic processes. Recently proposed trace‐element proxi...
Article
SignificanceThe permanent disappearance of mass-independent sulfur isotope fractionation (S-MIF) from the sedimentary record has become a widely accepted proxy for atmospheric oxygenation. This framework, however, neglects inheritance from oxidative weathering of pre-existing S-MIF-bearing sedimentary sulfide minerals (i.e., crustal memory), which...
Chapter
We addressed fundamental questions about the lithology, age, structure, and thermal evolution of the deep crust of the retroarc hinterland of the North American Cordilleran orogen through systematic investigation of zircons from Cretaceous plutons in the Snake Range and Kern Mountains of east-central Nevada. Geochronological (U-Pb) and geochemical...
Article
Tellurium-rich (Te) adularia-sericite epithermal Au-Ag deposits are an important current and future source of precious and critical metals. However, the source and evolution of ore-forming fluids in these deposits are masked by traditional bulk analysis of quartz oxygen isotope ratios that homogenize fine-scale textures and growth zones. To advance...
Article
The study of serpentinites and ophicarbonates from ophiolitic terrains provides a three-dimensional perspective on the hydration and carbonation processes affecting modern oceanic lithosphere. The Chenaillet ophiolite (western Alps) is interpreted as a fragment of an oceanic core complex that resembles a modern slow spreading center, and it was wea...
Article
Full-text available
The southern Coast Mountain batholith was episodically active from Jurassic to Eocene time and experienced four distinct high magmatic flux events during that period. Similar episodicity has been recognized in arcs worldwide, yet the mechanism(s) driving such punctuated magmatic behavior are debated. This study uses zircon Hf and O isotopes, with w...
Article
Full-text available
We present >500 zircon δ18O and Lu-Hf isotope analyses on previously dated zircons to explore the interplay between spatial and temporal magmatic signals in Zealandia Cordillera. Our data cover ~8500 km2 of middle and lower crust in the Median Batholith (Fiordland segment of Zealandia Cordillera) where Mesozoic arc magmatism along the paleo-Pacific...
Article
The Ediacaran Period (ca. 635-539 Ma) witnessed the earliest paleontological evidence for macroscopic life (i.e., Ediacara biota) and geochemical observations of the largest carbon cycle J o u r n a l P r e-p r o o f Journal Pre-proof anomaly in Earth history (i.e., Shuram Excursion, SE). Numerous hypotheses have been proposed for the origins of th...
Article
This study addresses the question of how and where arc magmas obtain their chemical and isotopic characteristics. The Wooley Creek batholith and Slinkard pluton are a tilted, mid-to upper-crustal part of a vertically extensive, late-Jurassic, arc-related magmatic system in the Klamath Mountains, northern California. The main stage of the system is...
Article
Full-text available
This study addresses the question of how and where arc magmas obtain their chemical and isotopic characteristics. The Wooley Creek batholith and Slinkard pluton are a tilted, mid- to upper-crustal part of a vertically extensive, late-Jurassic, arc-related magmatic system in the Klamath Mountains, northern California. The main stage of the system is...
Conference Paper
The largest carbon isotope (δ13C) negative anomaly recorded in marine carbonates in Earth history — the Ediacaran Shuram Excursion (SE) — preserves values down to ca. –10‰ on a global scale. Despite the intensive geochemical and theoretical work published in the past decade, its origin and the degree to which its geochemical signature has been diag...
Article
Zircon U-Pb dating is a powerful and widely used geochronologic technique to constrain the timing and rates of magmatic and high and lower-grade metamorphic processes, as well as sediment provenance. Zircon trace element (TE) compositions also record magmatic and metamorphic processes during zircon growth. In this study, zircon laser ablation split...
Article
Detrital chromites are commonly reported within Archean metasedimentary rocks, but have thus far garnered little attention for use in provenance studies. Systematic variations of Cr-Fe spinel mineral chemistry with changing tectonic setting has resulted in the extensive use of chromite as a petrogenetic indicator, and so detrital chromites represen...
Article
Full-text available
The 119 Ma Dinkey Dome pluton in the central Sierra Nevada Batholith is a peraluminous granite and contains magmatic garnet and zircon that are complexly zoned with respect to oxygen isotope ratios. Intracrystalline SIMS analysis tests the relative importance of magmatic differentiation processes vs. partial melting of metasedimentary rocks. Wherea...
Article
U–Pb ages, trace element content and oxygen isotope ratios of single zircons from five plagiogranite intrusions of the Troodos ophiolite were measured to determine their crystallization age and assess the importance of fractional crystallization versus crustal anatexis in their petrogenesis. The results indicate that oceanic magmatism in Troodos to...
Article
The Colorado Plateau has undergone as much as 1.8 km of uplift over the past 80 Ma, but never underwent the pervasive deformation common in the neighboring tectonic provinces of the western USA. To understand the source, timing and distribution of mantle hydration, and its role in plateau uplift, garnets from four eclogite xenoliths of the Moses Ro...
Article
Full-text available
Three tourmaline reference materials sourced from the Harvard Mineralogical and Geological Museum (schorl 112566, dravite 108796 and elbaite 98144), which are already widely used for the calibration of in situ boron isotope measurements, are characterised here for their oxygen and lithium isotope compositions. Homogeneity tests by secondary ion mas...
Article
The ability to constrain the petrogenesis of multiple serpentine generations recorded at the microscale is crucial for estimating the extent and conditions of modern versus fossil serpentinisation in ophiolites. To address matrix bias effects during oxygen isotope analysis by SIMS, we present the first investigation analysing antigorite in the comp...
Conference Paper
High Spatial-resolution Assessment of Diagenesis and Primary Isotopic Variability in Maastrichtian Molluscan Carbonates from Antarctica - Benjamin Linzmeier, Thomas Tobin, Peter Ward, Ian Orland, Daniella Assing, Kouki Kitajima, Phillip Gopon, Brian Huber, Shanan Peters, John Valley
Article
Full-text available
Earth's hydrological cycle was profoundly perturbed by massive carbon emissions during an ancient (56 Ma) global warming event referred to as the Paleocene‐Eocene thermal maximum (PETM). One approach to gaining valuable insight into the response of the hydrological cycle is to construct sea‐surface salinity (SSS) records that can be used to gauge c...
Article
Ediacaran-aged (635–541 million years ago) marine sediments contain a large negative carbon isotope (δ13C) excursion, in which carbonate δ13C values reach −12‰ (VPDB). Known as the ‘Shuram’ excursion, many workers have interpreted this δ13C record as an unprecedented perturbation to the global carbon cycle, leading to speculation about a causal con...
Article
Full-text available
Recent work suggests that the C- and O-isotope composition of laminated soil carbonate rinds can provide high-resolution (100s yr/sample) information about hydrologic processes and vegetation over tens of thousands of years. However, while this archive can potentially provide quantitative reconstructions, most interpretations have thus far been qua...
Article
Carbonate carbon isotope (δ¹³Ccarb) chemostratigraphy is a valuable tool in Precambrian stratigraphic correlation. The effectiveness of this tool rests on the assumption that δ¹³Ccarb data record global seawater signals. However, in some cases δ¹³Ccarb data may exhibit rapid and noisy stratigraphic variations that appear to have been influenced by...
Article
We present quantitative petrographic data, high spatial resolution oxygen isotope analyses of quartz cement, basin modelling and a kinetic model for quartz precipitation for two Paleocene-Eocene Wilcox Group sandstones from Texas and two Jurassic Fulmar Formation sandstones from the Central North Sea. At each location, one sandstone has been buried...
Article
Oxygen isotope analyses of diagenetic cements can provide detailed evidence of sedimentary burial processes and conditions, as the δ18O values of precipitating minerals reflect contemporaneous local δ18Owater and temperature conditions. Uncertainties in the timing and rates of pore water δ18O evolution in sedimentary basins can complicate interpret...
Article
The Reef Deposit is an anomalous AuCu occurrence in the Paleoproterozoic terranes of northern Wisconsin, better known as host to significant CuZn volcanogenic massive sulfide (VMS) deposits. Previous work using lead isotopes and fluid inclusions has identified a protracted development of the mineralization from initial formation as the root zone ve...
Article
The Paleocene-Eocene thermal maximum (PETM) was an extraordinary pulse of global warming that left an indelible mark on the Earth approximately 56 Ma ago. This warming event is associated with an addition of large amounts of 13 C-depleted carbon into the atmosphere-ocean system, but the magnitude of the negative carbon isotope excursion (CIE) signa...
Conference Paper
Carbonate carbon isotopes have been used widely to study Precambrian paleoclimate, paleoceanography, and chemostratigraphic correlation. This is particularly true in the study of Precambrian climatic change, oceanic and atmospheric redox conditions, and stratigraphic correlation, because few Precambrian fossils provide diagnostic information about...
Article
Corundum (Crn), including sapphire, occurs in emery pods surrounded by marble on the island of Naxos, Greece. The emery formed from bauxite deposited in karst that was metamorphosed to 400 to 700 °C at 20‐15 Ma. Many of these rocks initially appeared well suited for refractory accessory mineral (RAM) thermometry, which uses oxygen isotope fractiona...
Article
Diagenetic minerals preserve records of burial processes that overprint records of seawater chemistry and impact reservoir porosity. The Mississippian-Devonian aged Bakken Formation in the Williston Basin is a reservoir rock of economic importance whose productivity is affected by diagenetic carbonates, particularly dolomite-ankerite-series carbona...
Conference Paper
The globally-recorded Ediacaran Shuram Excursion (SE) represents the largest carbonate carbon isotope (δ13Ccarb) negative anomaly in Earth’s history. Typically, the SE is characterized by δ13Ccarb values that plunge to a nadir of ca. −10‰ over a short stratigraphic interval and then rise steadily in the overlying tens or hundreds of meters before r...
Conference Paper
The Marinoan glaciation (a.k.a. the Snowball Earth) represents a profound paleoclimatic anomaly in deep time. However, the detailed mechanism of its termination remains largely unknown. It was hypothesized that massive releases of methane via clathrate destabilization at ~635 Ma may have played a role in terminating the glaciation. A key piece of s...
Article
A Nanoscale Record of Impact-Induced Pb Mobility in Lunar Zircon - Volume 25 Supplement - Tyler B. Blum, David A. Reinhard, Matthew A. Coble, Michael J. Spicuzza, Yimeng Chen, Aaron J. Cavosie, Lutz Nasdala, Chutimun Chanmuang N., Ty J. Prosa, David J. Larson, John W. Valley
Article
Full-text available
Skarn garnets in the Mineral King roof pendant of the south–central Sierra Nevada within Sequoia National Park, California, USA reveal variable fluid chemistry with a significant component of meteoric water during metasomatism in the Early Cretaceous Sierra Nevada Batholith. We focus on andradite garnet associated with Pb–Zn mineralization in the W...
Article
Oxygen isotopes were analyzed in human teeth dating to approximately 1250 BC from a Bronze Age battlefield along the Tollense River in northwestern Germany. Tooth enamel was sectioned, prepared, and analyzed using Secondary Ion Mass Spectrometry (SIMS) and Confocal Laser Fluorescence Microscopy (CLFM). The results of the study indicate that diagene...
Book
Volume 16 of Reviews in Mineralogy inroduces to high-temperature stable isotope geochemistry and should provide an entry into the pertinent literature, as well as some understanding of the basic concepts and potential applications. The first three chapters focus on the theory and experimental data base for equilibrium, disequilibrium, and kinetics...
Book
Volume 43 of Reviews in Mineralogy and Geochemistry follows the 1986 Reviews in Mineralogy (Vol. 16) in approach but reflects significant changes in the field of Stable Isotope Geochemistry. In terms of new technology, new sub-disciplines, and numbers of researchers, the field has changed more in the past decade than in any other since that of its...
Technical Report
Full-text available
ABSTRACT A basic outline is established here for the dolomitization history of the mixed carbonate-clastic facies that comprise the middle Bakken tight-oil reservoir of the Williston Basin (Late Devonian – Early Mississippian). A mineralogical dataset compiled from sources in the public domain reveals a strong correspondence between the clay and do...
Data
Appendix S2. Measurement results from EPMA (n = 84 for each of the two zircon samples) at Universität Göttingen, Germany.
Data
Appendix S3. Documentation of locations of EPMA (Universität Göttingen, Germany) linescans, and plots and histograms of mass fractions of HfO2, ThO2 and UO2.
Data
Appendix S1. Details for ID‐TIMS analytical procedures in the laboratories.
Data
Appendix S4. Measurement results from SHRIMP analyses (Curtin University, Perth, Australia) including additional Concordia plots and Th/U histograms.
Article
Full-text available
Zircon xenocrysts from alkali basalts in Ratanakiri Province, Cambodia represent a unique low-Hf zircon within a 12,000 km long Indo-Pacific megacryst zone. Colorless, yellow, brown, and red crystals ({100}, {101}, subordinate {211}, {1103}), with hopper growth and corrosion features range up to 20 cm in size. Zircon chemistry indicates juvenile, Z...