A. Kate Souders
Kate Souders is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Igneous and Metamorphic Working Group
The Igneous and Metamorphic Working Group supports the Geologic Framework of the Intermountain West (IMW) Project by conducting geologic mapping in igneous terranes and research focused on understanding the magmatic and metamorphic processes that shaped the Intermountain West region and their implications for mineral resource exploration and tectonic history. This research provides a process-based...
From Outcrop to Ions: development and application of in-situ isotope ratio measurements to solve geologic problems
Project objectives are to (1) develop innovative analytical techniques for isotope geochemistry and U-Pb geochronology using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and (2) apply these techniques to collaborative research projects of high priority to the Mineral Resources Program, including studies related to the formation of "critical mineral" deposits, and...
Serving the U.S. Geological Survey’s geochronological data
Geochronological data provide essential information necessary for understanding the timing of geologic processes and events, as well as quantifying rates and timescales key to geologic mapping, mineral and energy resource and hazard assessments. The USGS’s National Geochronological Database (NGDB) contains over 30,000 radiometric ages, but no formal update has occurred in over 20 years...
U-Th-Pb Geochronology of the Mentor Anorthosite Intrusive Complex (MAIC) and Regional Plutonic Units U-Th-Pb Geochronology of the Mentor Anorthosite Intrusive Complex (MAIC) and Regional Plutonic Units
This U.S. Geological Survey (USGS) data release accompanies planned publication 'Geophysical architecture and geochronology of the Neoarchean Mentor anorthosite intrusive complex, northwestern Minnesota: largest anorthosite complex of the Superior Province?'. The data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology data...
LA-MC-ICP-MS Hf isotopes in zircons from the Mountain Pass Intrusive Suite, California LA-MC-ICP-MS Hf isotopes in zircons from the Mountain Pass Intrusive Suite, California
This U.S. Geological Survey (USGS) data release accompanies planned publication ‘Geochemistry and radiogenic isotopes constrain the mantle source region of the Mountain Pass Intrusive Suite, California' and planned data release 'Whole-rock geochemical and isotopic data for the Mountain Pass Intrusive Suite, California'. The data release includes laser ablation multi-collector inductively...
LA-ICP-MS U-Pb Geochronology Data for Igneous Rocks Constraining the Timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA LA-ICP-MS U-Pb Geochronology Data for Igneous Rocks Constraining the Timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA
This U.S. Geological Survey (USGS) data release accompanies planned publication ‘New constraints on location and timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA. The data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon data and/or U-Pb apatite data for two samples from the Upper Peninsula, Michigan, USA...
Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota
This U.S. Geological Survey (USGS) data release provides whole rock isotope geochemistry, zircon hafnium isotope geochemistry, feldspar mineral chemistry, and zircon, monazite, and xenotime geochronology for a paragneiss sampled from a drill core from North Dakota. The sample was collected from the 9-11R E-M Larson well in order to constrain the depositional age, provenance, metamorphic...
Zircon U-Pb data for Proterozoic rocks in southwestern Colorado and rocks from drill core from Wyoming, Montana, and Nebraska Zircon U-Pb data for Proterozoic rocks in southwestern Colorado and rocks from drill core from Wyoming, Montana, and Nebraska
This U.S. Geological Survey (USGS) data release provides U-Pb zircon data and geochronology for Proterozoic rocks in the Needle Mountains of southwestern Colorado and for Proterozoic rocks sampled from drill cores from Wyoming, Montana, and Nebraska. Samples from the Needle Mountains were collected in order to constrain the polyphase tectonic evolution of the area. Drill core samples are...
USGS Geochron: A Database of Geochronological and Thermochronological Dates and Data (ver. 4.0, May 2025) USGS Geochron: A Database of Geochronological and Thermochronological Dates and Data (ver. 4.0, May 2025)
USGS Geochron is a database of geochronological and thermochronological dates and data. The data set contains published ages, dates, analytical information, sample metadata including location, and source citations. The following analytical techniques are represented in the data set: 40Ar/39Ar, K-Ar, U-Th-Pb, Sm-Nd, Rb-Sr, Lu-Hf, fission track, luminescence, U-series, (U-Th)/He, Re-Os...
Filter Total Items: 14
Re-Os geochronology of molybdenite by LA-ICP-MS/MS Re-Os geochronology of molybdenite by LA-ICP-MS/MS
Re-Os geochronology is a powerful tool to directly date sulphide mineralisation using phases such as molybdenite, pyrite and chalcopyrite. We present a snapshot of a method in development utilizing laser ablation inductively coupled-plasma ‘triple quad’ mass spectrometry (LA-ICP-MS/MS) for Re-Os geochronology of molybdenite. While traditional LA-(MC)-ICP-MS measurements are limited by...
Authors
Amanda Souders, Jay Michael Thompson
New constraints on location and timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA New constraints on location and timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA
The Great Lakes tectonic zone (GLTZ) forms the boundary between the Wawa–Abitibi and Minnesota River Valley subprovinces within the Archean Superior Province. The GLTZ is concealed for all of its 1100 km length, except for a segment in the central Upper Peninsula of Michigan. There, it is exposed as a northwest-striking mylonite zone along a 11 km segment, extending to the onlap of...
Authors
Benjamin J. Drenth, Amanda Souders, William F. Cannon, Jay Michael Thompson
In situ Re-Os geochronology of Re-rich Palaeogene molybdenite by LA-ICP-MS/MS In situ Re-Os geochronology of Re-rich Palaeogene molybdenite by LA-ICP-MS/MS
In situ Re–Os geochronology by LA-ICP-MS/MS was previously demonstrated by reacting Os with CH4 or N2O reaction gasses. However, for both reactions, a minor proportion of the Re parent isotope also reacts, potentially leading to significant isobaric interferences of 187Re on 187Os, especially for young samples with little radiogenic in-growth. Here we present an interlaboratory...
Authors
Stijm Glorie, Jay Michael Thompson, Sarah E. Gilbert, Amanda Souders
Accuracy and precision of U–Pb zircon geochronology at high spatial resolution (7–20 μm spots) by laser ablation-ICP-single-collector-sector-field-mass spectrometry Accuracy and precision of U–Pb zircon geochronology at high spatial resolution (7–20 μm spots) by laser ablation-ICP-single-collector-sector-field-mass spectrometry
Use of small spots (≤20µm) for laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology is of increasing interest in the Earth sciences because the temporal record of geologic processes is often preserved on a fine-scale within zircon grains. However the systematic biases and external sources of uncertainity of U-Pb ages is poorly defined when...
Authors
P. Mukherjee, Amanda Souders, Paul J. Sylvester
Geochemical and geochronologic evidence for a contiguous northeastern Wyoming Province Geochemical and geochronologic evidence for a contiguous northeastern Wyoming Province
The extent and nature of the Wyoming Province, an Archean craton in southwestern Laurentia, are poorly understood due to limited exposure between spatially isolated basement-cored uplifts. This lack of exposure has led to debate about whether the northeastern Wyoming Province is underlain by contiguous Archean crust or Proterozoic rocks and suture zone associated with the Trans-Hudson...
Authors
Ian William Hillenbrand, Amy K. Gilmer, Amanda Souders, Ilya N. Bindeman
Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen
The crustal evolution of the southernmost ∼2000–1800 Ma Trans-Hudson orogen (THO) is enigmatic due to burial by Phanerozoic sediments. We provide new insights through petrochronologic analysis of a paragneiss drill core sample. Detrital zircon age peaks at 2625, 2340, and 1880 Ma and Hf isotopes suggest Paleoproterozoic arc development proximal to Archean source(s). Phase equilibria...
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Amanda Souders, Michael J. Jercinovic, Heather A. Lowers, Jorge A. Vazquez
Science and Products
Igneous and Metamorphic Working Group
The Igneous and Metamorphic Working Group supports the Geologic Framework of the Intermountain West (IMW) Project by conducting geologic mapping in igneous terranes and research focused on understanding the magmatic and metamorphic processes that shaped the Intermountain West region and their implications for mineral resource exploration and tectonic history. This research provides a process-based...
From Outcrop to Ions: development and application of in-situ isotope ratio measurements to solve geologic problems
Project objectives are to (1) develop innovative analytical techniques for isotope geochemistry and U-Pb geochronology using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and (2) apply these techniques to collaborative research projects of high priority to the Mineral Resources Program, including studies related to the formation of "critical mineral" deposits, and...
Serving the U.S. Geological Survey’s geochronological data
Geochronological data provide essential information necessary for understanding the timing of geologic processes and events, as well as quantifying rates and timescales key to geologic mapping, mineral and energy resource and hazard assessments. The USGS’s National Geochronological Database (NGDB) contains over 30,000 radiometric ages, but no formal update has occurred in over 20 years...
U-Th-Pb Geochronology of the Mentor Anorthosite Intrusive Complex (MAIC) and Regional Plutonic Units U-Th-Pb Geochronology of the Mentor Anorthosite Intrusive Complex (MAIC) and Regional Plutonic Units
This U.S. Geological Survey (USGS) data release accompanies planned publication 'Geophysical architecture and geochronology of the Neoarchean Mentor anorthosite intrusive complex, northwestern Minnesota: largest anorthosite complex of the Superior Province?'. The data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology data...
LA-MC-ICP-MS Hf isotopes in zircons from the Mountain Pass Intrusive Suite, California LA-MC-ICP-MS Hf isotopes in zircons from the Mountain Pass Intrusive Suite, California
This U.S. Geological Survey (USGS) data release accompanies planned publication ‘Geochemistry and radiogenic isotopes constrain the mantle source region of the Mountain Pass Intrusive Suite, California' and planned data release 'Whole-rock geochemical and isotopic data for the Mountain Pass Intrusive Suite, California'. The data release includes laser ablation multi-collector inductively...
LA-ICP-MS U-Pb Geochronology Data for Igneous Rocks Constraining the Timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA LA-ICP-MS U-Pb Geochronology Data for Igneous Rocks Constraining the Timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA
This U.S. Geological Survey (USGS) data release accompanies planned publication ‘New constraints on location and timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA. The data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon data and/or U-Pb apatite data for two samples from the Upper Peninsula, Michigan, USA...
Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota
This U.S. Geological Survey (USGS) data release provides whole rock isotope geochemistry, zircon hafnium isotope geochemistry, feldspar mineral chemistry, and zircon, monazite, and xenotime geochronology for a paragneiss sampled from a drill core from North Dakota. The sample was collected from the 9-11R E-M Larson well in order to constrain the depositional age, provenance, metamorphic...
Zircon U-Pb data for Proterozoic rocks in southwestern Colorado and rocks from drill core from Wyoming, Montana, and Nebraska Zircon U-Pb data for Proterozoic rocks in southwestern Colorado and rocks from drill core from Wyoming, Montana, and Nebraska
This U.S. Geological Survey (USGS) data release provides U-Pb zircon data and geochronology for Proterozoic rocks in the Needle Mountains of southwestern Colorado and for Proterozoic rocks sampled from drill cores from Wyoming, Montana, and Nebraska. Samples from the Needle Mountains were collected in order to constrain the polyphase tectonic evolution of the area. Drill core samples are...
USGS Geochron: A Database of Geochronological and Thermochronological Dates and Data (ver. 4.0, May 2025) USGS Geochron: A Database of Geochronological and Thermochronological Dates and Data (ver. 4.0, May 2025)
USGS Geochron is a database of geochronological and thermochronological dates and data. The data set contains published ages, dates, analytical information, sample metadata including location, and source citations. The following analytical techniques are represented in the data set: 40Ar/39Ar, K-Ar, U-Th-Pb, Sm-Nd, Rb-Sr, Lu-Hf, fission track, luminescence, U-series, (U-Th)/He, Re-Os...
Filter Total Items: 14
Re-Os geochronology of molybdenite by LA-ICP-MS/MS Re-Os geochronology of molybdenite by LA-ICP-MS/MS
Re-Os geochronology is a powerful tool to directly date sulphide mineralisation using phases such as molybdenite, pyrite and chalcopyrite. We present a snapshot of a method in development utilizing laser ablation inductively coupled-plasma ‘triple quad’ mass spectrometry (LA-ICP-MS/MS) for Re-Os geochronology of molybdenite. While traditional LA-(MC)-ICP-MS measurements are limited by...
Authors
Amanda Souders, Jay Michael Thompson
New constraints on location and timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA New constraints on location and timing of the Great Lakes tectonic zone, central Upper Peninsula, Michigan, USA
The Great Lakes tectonic zone (GLTZ) forms the boundary between the Wawa–Abitibi and Minnesota River Valley subprovinces within the Archean Superior Province. The GLTZ is concealed for all of its 1100 km length, except for a segment in the central Upper Peninsula of Michigan. There, it is exposed as a northwest-striking mylonite zone along a 11 km segment, extending to the onlap of...
Authors
Benjamin J. Drenth, Amanda Souders, William F. Cannon, Jay Michael Thompson
In situ Re-Os geochronology of Re-rich Palaeogene molybdenite by LA-ICP-MS/MS In situ Re-Os geochronology of Re-rich Palaeogene molybdenite by LA-ICP-MS/MS
In situ Re–Os geochronology by LA-ICP-MS/MS was previously demonstrated by reacting Os with CH4 or N2O reaction gasses. However, for both reactions, a minor proportion of the Re parent isotope also reacts, potentially leading to significant isobaric interferences of 187Re on 187Os, especially for young samples with little radiogenic in-growth. Here we present an interlaboratory...
Authors
Stijm Glorie, Jay Michael Thompson, Sarah E. Gilbert, Amanda Souders
Accuracy and precision of U–Pb zircon geochronology at high spatial resolution (7–20 μm spots) by laser ablation-ICP-single-collector-sector-field-mass spectrometry Accuracy and precision of U–Pb zircon geochronology at high spatial resolution (7–20 μm spots) by laser ablation-ICP-single-collector-sector-field-mass spectrometry
Use of small spots (≤20µm) for laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology is of increasing interest in the Earth sciences because the temporal record of geologic processes is often preserved on a fine-scale within zircon grains. However the systematic biases and external sources of uncertainity of U-Pb ages is poorly defined when...
Authors
P. Mukherjee, Amanda Souders, Paul J. Sylvester
Geochemical and geochronologic evidence for a contiguous northeastern Wyoming Province Geochemical and geochronologic evidence for a contiguous northeastern Wyoming Province
The extent and nature of the Wyoming Province, an Archean craton in southwestern Laurentia, are poorly understood due to limited exposure between spatially isolated basement-cored uplifts. This lack of exposure has led to debate about whether the northeastern Wyoming Province is underlain by contiguous Archean crust or Proterozoic rocks and suture zone associated with the Trans-Hudson...
Authors
Ian William Hillenbrand, Amy K. Gilmer, Amanda Souders, Ilya N. Bindeman
Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen
The crustal evolution of the southernmost ∼2000–1800 Ma Trans-Hudson orogen (THO) is enigmatic due to burial by Phanerozoic sediments. We provide new insights through petrochronologic analysis of a paragneiss drill core sample. Detrital zircon age peaks at 2625, 2340, and 1880 Ma and Hf isotopes suggest Paleoproterozoic arc development proximal to Archean source(s). Phase equilibria...
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Amanda Souders, Michael J. Jercinovic, Heather A. Lowers, Jorge A. Vazquez