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Christopher Holm-Denoma

Chris Holm-Denoma is a Research Geologist at the U.S. Geological Survey in Denver, CO.

He is currently involved in studies related to the structure, tectonics, and geochronology of regions with mineral deposits. Chris started his career at the the USGS as a postdoc in the Mendenhall Research Fellowship Program where he studied the structure and stratigraphy of the Roberts Mountains allochthon as related to Carlin-type Au deposits. Chris was an Lecturer at the University of Vermont from 2007-2008 where he taught Introductory Geology, Petrology, and a seminar in Appalachian Geology. He also spent a year in Minneapolis as a visiting scholar at the University of Minnesota and concurrently taught Geology and Oceanography courses at North Hennepin Community College. During his Ph.D. he used detailed mapping, structural analyses and isotopic/geochemical methods to investigate the Paleozoic evolution of a backarc and associated igneous rocks in the southern Appalachians. His areas of expertise include: structure/tectonics, field mapping, in situ geochronology (SHRIMP and LA-ICP-MS) and trace element geochemistry.

Education and Certifications

  • Ph.D., Geological Sciences, Florida State University, 2006

  • B.S., Geology, The George Washington University, 1998

Science and Products

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plasma lab instruments

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...
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
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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...
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Map of basement domains

Basement Tectonic Framework of the U.S.: Role of Cratonization of Juvenile Crust and Structural Modification in Forming Metallogenic Provinces

Project objectives were to publish a map of the nation's geologic basement. The map portrayed these pieces (domains) from the most ancient to recent, by the events that influenced their composition, starting with their origin.
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
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Basement Tectonic Framework of the U.S.: Role of Cratonization of Juvenile Crust and Structural Modification in Forming Metallogenic Provinces

Project objectives were to publish a map of the nation's geologic basement. The map portrayed these pieces (domains) from the most ancient to recent, by the events that influenced their composition, starting with their origin.
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granitoid

Petrogenesis and REE Metallogenesis of 1.4 Ga Magmatism in the Conterminous U.S.

This project evaluated the petrology and metallogeny of rare earth element-mineralized 1.4 Ga intrusive systems at Mountain Pass and in the St. Francois Mountains relative to those of other, apparently, unmineralized 1.4 Ga intrusive systems in the conterminous U.S.
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
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Petrogenesis and REE Metallogenesis of 1.4 Ga Magmatism in the Conterminous U.S.

This project evaluated the petrology and metallogeny of rare earth element-mineralized 1.4 Ga intrusive systems at Mountain Pass and in the St. Francois Mountains relative to those of other, apparently, unmineralized 1.4 Ga intrusive systems in the conterminous U.S.
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U-Pb zircon data for: Upper Triassic and Jurassic sedimentary rocks from Sonora, MX

This laser ablation ICPMS U-Pb zircon data set supports stratigraphic, biostratigraphic and age interpretations of the of the fossil-plant-bearing El Game?o Formation of west-central Sonora, Mexico and the potentially age-correlative fossil-plant-bearing Santa Clara and Coyote formations of southeastern Sonora, Mexico. The zircon data provides minimum age constraints (maximum depositional ages) fo
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Geology, Geophysics, and Geochemistry Science Center

Data to accompany U.S. Geological Survey Data Series 1099: Petrographic, geochemical and geochronologic data for Cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada

This dataset is the assembled analytical results of geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada. Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during geologic map
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

U-Pb data for: In situ LA-ICPMS U-Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to Tertiary

This dataset accompanies the publication, 'In situ LA-ICPMS U-Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to Tertiary', published in Chemical Geology (https://doi.org/10.1016/j.chemgeo.2018.03.008), which reports a LA-ICPMS analytical procedure for dating cassiterite, a main ore mineral in tin deposit
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Geologic map of the Poncha Pass area, Chaffee, Fremont, and Saguache Counties, Colorado

This report presents a 1:24,000-scale geologic map, cross sections, and descriptive and interpretative text for the Poncha Pass area in central Colorado. The map area is irregular in shape, covering all of one 7 ½' quadrangle (Poncha Pass) and parts of five others (Mount Ouray, Maysville, Salida West, Salida East, and Wellsville). The map boundaries were drawn to cover all of the “Poncha mountain
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Geosciences and Environmental Change Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 27

Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska

We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the Healy schis
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Energy and Minerals, Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

High spatial resolution U-Pb geochronology and Pb isotope geochemistry of magnetite-apatite ore from the Pea Ridge iron oxide-apatite deposit, St. Francois Mountains, southeast Missouri, USA

The Pea Ridge iron oxide-apatite (IOA) deposit is one of the major rhyolite-hosted magnetite deposits of the St. Francois Mountains terrane, which is located within the Mesoproterozoic (1.5–1.3 Ga) Granite-Rhyolite province in the U.S. Midcontinent. Precise and accurate determination of the timing and duration of oreforming processes in this deposit is crucial for understanding its origin and plac
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

The Permian–Triassic transition in Colorado

The Lykins Formation and its equivalents in Colorado are a stratigraphically poorly constrained suite of redbeds and intercalated stromatolitic carbonates, which is hypothesized to span the Permian-Triassic boundary. Herein we present a preliminary detrital zircon geochronology, new fossil occurrences, and δ13C chemostratigraphy for exposures along the Front Range and in southeastern Colorado, to
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Geology, Geophysics, and Geochemistry Science Center

Geochemical, modal, and geochronologic data for 1.4 Ga A-type granitoid intrusions of the conterminous United States

Introduction The purpose of this report is to present available geochemical, modal, and geochronologic data for approximately 1.4 billion year (Ga) A-type granitoid intrusions of the United States and to make those data available to ongoing petrogenetic investigations of these rocks. A-type granites, as originally defined by Loiselle and Wones (1979), are iron-enriched granitoids (synonymous with
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center

A Laurentian margin back-arc: the Ordovician Wedowee-Emuckfaw-Dahlonega basin

Independent researchers working in the Talladega belt, Ashland-Wedowee-Emuckfaw belt, and Opelika Complex of Alabama, as well as the Dahlonega gold belt and western Inner Piedmont of Alabama, Georgia, and the Carolinas, have mapped stratigraphic sequences unique to each region. Although historically considered distinct terranes of disparate origin, a synthesis of data suggests that each includes l
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Basement domain map of the conterminous United States and Alaska

The basement-domain map is a compilation of basement domains in the conterminous United States and Alaska designed to be used at 1:5,000,000-scale, particularly as a base layer for national-scale mineral resource assessments. Seventy-seven basement domains are represented as eighty-three polygons on the map. The domains are based on interpretations of basement composition, origin, and architecture
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Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center

Early to Middle Ordovician back-arc basin in the southern Appalachian Blue Ridge: characteristics, extent, and tectonic significance

Fault-dismembered segments of a distinctive, extensive, highly allochthonous, and tectonically significant Ordovician (ca. 480–460 Ma) basin, which contains suites of bimodal metavolcanic rocks, associated base metal deposits, and thick immature deep-water (turbiditic) metasediments, occur in parts of the southern Appalachian Talladega belt, eastern Blue Ridge, and Inner Piedmont of Alabama, Georg
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Integration of new geologic mapping and satellite-derived quartz mapping yields insights into the structure of the Roberts Mountains allochthon applicable to assessments for concealed Carlin-type gold deposits

Geologic mapping and remote sensing across north-central Nevada enable recognition of a thick sheet of Middle and Upper Ordovician Valmy Formation quartzite that structurally overlies folded and faulted Ordovician through Devonian stratigraphic units of the Roberts Mountains allochthon. In the northern Independence Mountains and nearby Double Mountain area, the Valmy Formation is in fault contact
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Geology of the Mount Rogers area, revisited: Evidence of Neoproterozoic continental rifting, glaciation, and the opening and closing of the Iapetus ocean, Blue Ridge, VA–NC–TN

Recent field and geochronological studies in eight 7.5-minute quadrangles near Mount Rogers in Virginia, North Carolina and Tennessee recognize important stratigraphic and structural relationships for the Neoproterozoic Mount Rogers and Konnarock formations, the northeast end of the Mountain City window, the separation of Mesoproterozoic rocks of the Blue Ridge into three age groups, and timing an
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Florence Bascom Geoscience Center

Review of the geochemistry and metallogeny of approximately 1.4 Ga granitoid intrusions of the conterminous United States

The conterminous United States hosts numerous volumetrically significant and geographically dispersed granitoid intrusions that range in age from 1.50 to 1.32 billion years before present (Ga). Although previously referred to as A-type granites, most are better described as ferroan granites. These granitoid intrusions are distributed in the northern and central Rocky Mountains, the Southwest, the
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

In situ LA-ICPMS U–Pb dating of cassiterite without a known-age matrix-matched reference material: Examples from worldwide tin deposits spanning the Proterozoic to the Tertiary

Cassiterite (SnO2), a main ore mineral in tin deposits, is suitable for U–Pb isotopic dating because of its relatively high U/Pb ratios and typically low common Pb. We report a LA-ICPMS analytical procedure for U–Pb dating of this mineral with no need for an independently dated matrix-matched cassiterite standard. LA-ICPMS U-Th-Pb data were acquired while using NIST 612 glass as a primary non-matr
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Structural evolution of a gold-bearing transtensional zone within the Archean Porcupine-Destor deformation zone, southern Abitibi greenstone belt, eastern Ontario, Canada

The Garrison camp comprises four structurally distinct orogenic gold deposits that formed in different host lithologies during progressive deformation. Detailed field mapping, drill core logging, and geochronological constraints suggest that the 2678 ± 2 Ma Garrison granitic stock played a fundamental rheological role in the location of the four deposits. Initial local shear movement occurred alon
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Geology, Geophysics, and Geochemistry Science Center

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