Igneous petrology and isotope geochemistry, with particular emphasis on the origin and evolution of melts associated with subduction zones.
Professional Experience
2012 - Present Research Geologist, USGS Alaska Science Center, Anchorage, Alaska
2011 - 2012 Postdoctoral Research Associate, WWU - University of Münster
2005 - 2011 Research and Teaching Assistant, University of California, Santa Cruz, CA
Education and Certifications
Ph.D. 2011 University of California, Santa Cruz, CA Earth Sciences
M.S. 2005 Northern Arizona University, Flagstaff, AZ Geology
B.S. 1999 University of Florida, Gainesville, FL Geology
Affiliations and Memberships*
American Geophysical Union
Geochemical Society
Geological Society of America
InterRIDGE
Science and Products
Metallogeny and Tectonics of the Lake Clark and Neacola Mountains Region, South-central Alaska
U-Pb Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-ablation Split Stream (LASS) Analysis of Igneous and Metamorphic Zircons from the Yukon-Tanana Upland, Eastern Alaska
U-Pb Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Western Alaska Range
Uranium-Lead Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Darby Mountains Area, Seward Peninsula, Alaska
Whole Rock Major and Trace Element Chemistry for Igneous and Metamorphic Rocks from the Yukon-Tanana Upland, Alaska
Whole Rock Major and Trace Element Chemistry for Igneous Rocks from Tyonek, Lime Hills, Talkeetna, McGrath, and Lake Clark Quadrangles, Western Alaska Range, Alaska
Whole Rock Major and Trace Element Chemistry for Igneous and Sedimentary Rocks from the Western Alaska Range, Alaska
U-Pb Isotopic Data and Ages of Zircon and Titanite from Rocks from the Western Alaska Range, Northern Aleutian Range, Taylor Mountains, and Tikchik Mountains Regions, Alaska
Chemical geodynamics insights from a machine learning approach
Juvenile continental crust evolution in a modern oceanic arc setting: Petrogenesis of Cenozoic felsic plutons in Fiji, SW Pacific
Breaking up is hard to do: Magmatism during oceanic arc breakup, subduction reversal, and cessation
Sr, Nd, Hf and Pb isotope geochemistry of Early Miocene shoshonitic lavas from the South Fiji Basin: Note
Cretaceous to Oligocene magmatic and tectonic evolution of the western Alaska Range: insights from U-Pb and 40Ar/39Ar geochronology
Basalt geochemistry and mantle flow during early backarc basin evolution: Havre Trough and Kermadec Arc, southwest Pacific
Links between tectonics, magmatism, and mineralization in the formation of Late Cretaceous porphyry systems in the Yukon-Tanana upland, eastern Alaska, USA
U-Pb and Lu-Hf isotope, age, and trace-element data from zircons at four sites in the western Alaska Range and Talkeetna Mountains, Alaska
Copahue volcano and its regional magmatic setting
GIS-Based Identification of Areas with Mineral Resource Potential for Six Selected Deposit Groups, Bureau of Land Management Central Yukon Planning Area, Alaska
Effects of simple acid leaching of crushed and powdered geological materials on high-precision Pb isotope analyses
Science and Products
- Science
Metallogeny and Tectonics of the Lake Clark and Neacola Mountains Region, South-central Alaska
Alaska hosts a well-documented belt of ore deposits that lies roughly parallel to the Alaska Range, beginning at the Alaska Peninsula in the southwest, continuing up through the Fairbanks Mining District in the north, and curving back into the Tintina Gold Belt on its eastern end. Known mineral prospects and occurrences include porphyry copper, intrusion-related gold, volcanogenic massive sulfides... - Data
U-Pb Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-ablation Split Stream (LASS) Analysis of Igneous and Metamorphic Zircons from the Yukon-Tanana Upland, Eastern Alaska
This data set contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the Yukon-Tanana Upland, eastern Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2013 to 2019. Zircon was obtained from these igneous rocks to determine the crysU-Pb Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Western Alaska Range
This data set contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the western Alaska Range of south-central Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2011 to 2013. We also analyzed portions of remainders of previously colUranium-Lead Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Darby Mountains Area, Seward Peninsula, Alaska
This data set contains uranium-lead (U-Pb) isotopic data and ages, hafnium (Hf) isotope data, and trace element concentrations of zircon from igneous rocks collected from the Darby Mountains area of the Seward Peninsula, Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted in 2017. The data tables accompanying thisWhole Rock Major and Trace Element Chemistry for Igneous and Metamorphic Rocks from the Yukon-Tanana Upland, Alaska
This data set consists of one table containing whole-rock geochemistry data for 753 igneous and metamorphic rocks from the Yukon-Tanana upland of eastern interior Alaska, collected between 2013 and 2019. All materials were analyzed by ALS Global, between 2014 and 2020, by a range of different techniques, so multiple unique entries for a given element relate to different analytical methods or prepaWhole Rock Major and Trace Element Chemistry for Igneous Rocks from Tyonek, Lime Hills, Talkeetna, McGrath, and Lake Clark Quadrangles, Western Alaska Range, Alaska
This data release contains whole rock major and trace element data for 69 igneous rock samples collected from the Western Alaska Range between 2011 and 2012. The Series field relates to chronological units discussed in Jones et al. (2021, Geosphere) and Todd et al. (2022 IN PREP). Descriptions are from original collector notebooks and are provided here for informational purposes only.Whole Rock Major and Trace Element Chemistry for Igneous and Sedimentary Rocks from the Western Alaska Range, Alaska
This data release contains whole rock major and trace element data for 399 igneous and sedimentary rock samples collected from the Western Alaska Range between 1968 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey. All materials were analyzed by ALS Global, between 2014 and 2018, by a range of different techniques, so multiple unique entries for a given element reU-Pb Isotopic Data and Ages of Zircon and Titanite from Rocks from the Western Alaska Range, Northern Aleutian Range, Taylor Mountains, and Tikchik Mountains Regions, Alaska
This data set contains U-Pb isotopic data and ages of zircon and titanite from igneous and metamorphic rocks collected from the western Alaska and northern Aleutian Range of south-central Alaska. The data sets also contain U-Pb isotopic data and ages of detrital zircon from sedimentary and metasedimentary rocks collected in the same region but also from the Taylor and Wood River Mountains of south - Multimedia
- Publications
Chemical geodynamics insights from a machine learning approach
The radiogenic isotope heterogeneity of oceanic basalts is often assessed using 2D isotope ratio diagrams. But because the underlying data are at least six dimensional (87Sr/86Sr, 143Nd/144Nd, 176Hf/177Hf, and 208,207,206Pb/204Pb), it is important to examine isotopic affinities in multi-dimensional data space. Here, we apply t-distributed stochastic neighbor embedding (t-SNE), a multi-variate statAuthorsAndreas Stracke, M. Willig, F. Genske, P. Béguelin, Erin ToddJuvenile continental crust evolution in a modern oceanic arc setting: Petrogenesis of Cenozoic felsic plutons in Fiji, SW Pacific
Viti Levu, Fiji, provides one of the best exposed Phanerozoic analogues for the formation of juvenile continental crust in an intra-oceanic setting. Tonalites and trondhjemites are present in several large (75–150 km2) adjacent, mid-Cenozoic plutons. We report major and trace element data including rare earth element (REE) and high-precision high field strength element (HFSE) compositions, new Hf-AuthorsChris S. Marien, Elizabeth Kathleen Drewes, Allen Stork, Erin Todd, James B Gill, J. Elis Hoffman, Kenichiro Tani, Charlotte M. Allen, Carsten MünkerBreaking up is hard to do: Magmatism during oceanic arc breakup, subduction reversal, and cessation
The formerly continuous Vitiaz Arc broke into its Vanuatu and Fijian portions during a reversal of subduction polarity in the Miocene. Basaltic volcanism in Fiji that accompanied the breakup ranged from shoshonitic to low-K and boninitic with increasing distance from the broken edge of the arc that, presumably, marks the broken edge of the slab. The Sr-Pb-Nd isotope ratios of the slab-derived compAuthorsJames F. Gill, Erin Todd, Kaj Hoernle, Folkmar Hauff, Alison Ann Price, Matthew G. JacksonSr, Nd, Hf and Pb isotope geochemistry of Early Miocene shoshonitic lavas from the South Fiji Basin: Note
We present new Sr, Nd, Hf and Pb isotope data for Early Miocene shoshonitic and high-K lavas dredged from seamounts in the South Fiji Basin, southwest Pacific Ocean. Our analyses provide a useful reference dataset for this distinctive compositional suite. The shoshonitic lavas formed in an intra-oceanic back-arc basin setting and are broadly coeval with nearby arc and back-arc basin lavas. FurtherAuthorsNick Mortimer, Delphine Bosch, Christine Laporte-Magoni, Erin Todd, James B GillCretaceous to Oligocene magmatic and tectonic evolution of the western Alaska Range: insights from U-Pb and 40Ar/39Ar geochronology
New U-Pb and 40Ar/39Ar ages integrated with geologic mapping and observations across the western Alaska Range constrain the distribution and tectonic setting of Cretaceous to Oligocene magmatism along an evolving accretionary plate margin in south-central Alaska. These rocks were emplaced across basement domains that include Neoproterozoic to Jurassic carbonate and siliciclastic strata of the FareAuthorsJames V. Jones, Erin Todd, Stephen E. Box, Peter J. Haeussler, Christopher Holm-Denoma, Susan M. Karl, Garth E. Graham, Dwight C. Bradley, Andrew R.C. Kylander-Clark, Richard M. Friedman, Paul W. LayerBasalt geochemistry and mantle flow during early backarc basin evolution: Havre Trough and Kermadec Arc, southwest Pacific
The Havre Trough (HT) backarc basin in the southwest Pacific is in the rifting stage of development. We distinguish five types of basalt there based on their amount and kind of slab component: backarc basalts (BAB) with little or no slab component, modified BAB with slight amounts, reararc (RA) with more, remnants of the preexisting arc (Colville Ridge horsts), and arc front volcanoes within the HAuthorsJames B Gill, Kaj Hoernle, Erin Todd, Folkmar Hauff, Reinhard Werner, Christian Timm, Dieter Garbe-Schönberg, Marcus GutjahrLinks between tectonics, magmatism, and mineralization in the formation of Late Cretaceous porphyry systems in the Yukon-Tanana upland, eastern Alaska, USA
Cretaceous-Paleocene porphyry Cu(±Mo±Au) occurrences are scattered throughout the Yukon-Tanana upland in eastern Alaska. Known occurrences in eastern Alaska are poorly characterized, despite a resurgence in exploration. Porphyry deposits in the upland are emplaced into structurally complex metamorphic rocks representing a variety of tectonic environments, resulting in diverse alteration and mineraAuthorsDouglas C. Kreiner, James V. Jones, Erin Todd, Christopher Holm-Denoma, Jonathan Caine, Jeff BenowitzU-Pb and Lu-Hf isotope, age, and trace-element data from zircons at four sites in the western Alaska Range and Talkeetna Mountains, Alaska
This Division of Geological & Geophysical Surveys (DGGS) Raw Data File presents U-Pb geochronology and Lu-Hf isotopic compositions, age-dating results, and additional trace-elemental composition of zircons from four granitoids sampled during investigations by DGGS geologists in the western Alaska Range and the Talkeetna Mountains. The purpose of the Lu-Hf and U-Pb isotopic study was to better undeAuthorsErin Todd, Andrew R. C. Kylander-Clark, Alicja Wypych, Evan Twelker, Karri R. SicardCopahue volcano and its regional magmatic setting
Copahue volcano (Province of Neuquen, Argentina) has produced lavas and strombolian deposits over several 100,000s of years, building a rounded volcano with a 3 km elevation. The products are mainly basaltic andesites, with the 2000–2012 eruptive products the most mafic. The geochemistry of Copahue products is compared with those of the main Andes arc (Llaima, Callaqui, Tolhuaca), the older CaviahAuthorsJ. C. Varekamp, J. E. Zareski, L. M. Camfield, Erin ToddGIS-Based Identification of Areas with Mineral Resource Potential for Six Selected Deposit Groups, Bureau of Land Management Central Yukon Planning Area, Alaska
This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and paleoplacerAuthorsJames V. Jones, Susan M. Karl, Keith A. Labay, Nora B. Shew, Matthew Granitto, Timothy S. Hayes, Jeffrey L. Mauk, Jeanine M. Schmidt, Erin Todd, Bronwen Wang, Melanie B. Werdon, Douglas B. YagerEffects of simple acid leaching of crushed and powdered geological materials on high-precision Pb isotope analyses
We present new results of simple acid leaching experiments on the Pb isotope composition of USGS standard reference material powders and on ocean island basalt whole rock splits and powders. Rock samples were leached with cold 6 N HCl in an ultrasonic bath, then on a hot plate, and washed with ultrapure H2O before sample digestion in HF‐HNO3 and chromatographic purification of Pb. Lead isotope anaAuthorsErin Todd, Andreas Stracke, Erik Scherer
*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