Due to a lapse in appropriations, the majority of USGS websites may not be up to date and may not reflect current conditions. Websites displaying real-time data, such as Earthquake and Water and information needed for public health and safety will be updated with limited support. Additionally, USGS will not be able to respond to inquiries until appropriations are enacted. For more information, please see www.doi.gov/shutdown
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.
Ph.D., Geological Sciences, Florida State University, 2006
B.S., Geology, The George Washington University, 1998
Science and Products
This project will allow us to (1) develop innovative analytical techniques for isotope geochemistry and U-Pb geochronology using plasma ionization mass spectrometry and (2) apply our new analytical techniques to collaborative research projects of high priority to the Mineral Resources Program, including studies related to the U.S. midcontinent region and Alaska, and/or processes related to the...
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...Nassif, Miguel T.; Kuiper, Yvette D.; Goldfarb, Richard J.; Monecke, Thomas; Holm-Denoma, Christopher S.
Processes and facies relationships in a Lower(?) Devonian rocky shoreline depositional environment, East Lime Creek Conglomerate, south‐western Colorado, USA
Rocky shorelines are relatively common features along modern coastlines, but few have been recognized in the geological record. The hard substrates of rocky shorelines telescope the width of offshore marine environments, thus the diagnostic deposits observed in such settings today have a low preservation potential due to small accommodation space...Evans, James E.; Holm-Denoma, Christopher S.
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...Neymark, Leonid; Holm-Denoma, Christopher S.; Moscati, Richard J.
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...du Bray, Edward A.; Holm-Denoma, Christopher S.; Lund, Karen; Premo, Wayne R.
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...Dusel-Bacon, Cynthia; Holm-Denoma, Christopher S.; Jones, James V.; Aleinikoff, John N.; Mortensen, James K.
The Valmy thrust sheet: A regional structure formed during the protracted assembly of the Roberts Mountains allochthon, Nevada, USA
A synthesis of field, biostratigraphic, detrital zircon geochronologic, and remote sensing data across north-central Nevada, United States, defines a thick, regionally extensive sheet of Middle–Upper Ordovician Valmy Formation quartzite that structurally overlies deformed early Paleozoic units of the Roberts Mountains allochthon. Late Paleozoic...Holm-Denoma, Christopher S.; Hofstra, Albert H.; Rockwell, Barnaby W.; Noble, Paula J.
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...Neymark, Leonid; Holm-Denoma, Christopher S.; Pietruszka, Aaron; Aleinikoff, John N.; Fanning, C. Mark; Pillers, Renee M.; Moscati, Richard J.
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...Hagadorn, James S.; Whitely, Karen R.; Lahey, Bonita L.; Henderson, Charles M.; Holm-Denoma, Christopher S.
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...Merschat, Arthur J.; Merschat, Arthur J.; Southworth, C. Scott; Holm-Denoma, Christopher S.; McAleer, Ryan J.
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 (...du Bray, Edward A.; Holm-Denoma, Christopher S.; San Juan, Carma A.; Lund, Karen; Premo, Wayne R.; DeWitt, Ed
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...Barineau, Clinton I.; Tull, James F.; Holm-Denoma, Christopher S.
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...Lund, Karen; Box, Stephen E.; Holm-Denoma, Christopher S.; San Juan, Carma A.; Blakely, Richard J.; Saltus, Richard W.; Anderson, Eric D.; DeWitt, Ed