This Data Release accompanies the publication, "Paleogene sedimentary basin development in southern Nevada, USA" by Lundstern and others (2024) in the journal Lithosphere. Included here are U-Pb detrital zircon and Ar/Ar feldspar geochronologic data for middle Cenozoic sedimentary and volcanic rocks collected by Jens-Erik Lundstern and Theresa M. Schwartz in several parts of southern Nevada, U.S. The target strata are the lowest Cenozoic sedimentary rocks deposited above the base-Cenozoic unconformity. U-Pb detrital zircon data were obtained at the University of Arizona LaserChron Center in Tucson, Arizona in February 2021, October 2021, and January 2023. 40Ar/39Ar geochronologic data were collected at the U.S. Geological Survey in Denver, Colorado.

This document describes sedimentary rock samples and their associated detrital zircon U-Pb data that were collected to support geologic mapping and research initiatives within the context of the Geologic Framework of the Intermountain West Project. The data characterize the age and/or provenance of Neoproterozoic to Miocene strata exposed across the Intermountain West region of the United States, with outcrop locations distributed across parts of California, Colorado, Montana, Nevada, New Mexico, and Utah. Most detrital zircon U-Pb data presented herein were acquired at the University of Arizona LaserChron Center (Tucson, AZ) between 2019 and 2024; a small subset of data was acquired at the U.S. Geological Survey Plasma Lab (Lakewood, CO) in 2021.

This data release includes raw detrital zircon U-Pb data for isolated sandstones in Upper Triassic deposits of the Auld Lang Syne basin of northwest Nevada, USA. Detrital zircon U-Pb data for 11 sandstone samples (3269 zircon U-Pb dates) were acquired via LA-ICP-MS at the University of Arizona LaserChron Center for 11 sandstone samples. Primary insights from the data are twofold: 1) The data provide information about sediment provenance and indicate that sediment of the Auld Lang Syne basin was primarily derived from near the ancestral Ouachita orogen of Texas and Oklahoma. Sediment was transported to the Auld Lang Syne basin by a Late Triassic transcontinental river system, recorded today by the Upper Triassic Chinle and Dockum Groups of the southern continental interior region. 2) The youngest detrital zircon dates in each age distribution provide estimates of maximum depositional age. Maximum depositional ages are consistent with Late Triassic (Norian) deposition in the Auld Lang Syne basin, an age previously constrained by sparse invertebrate fossil data. This data release includes raw detrital zircon U-Pb data for isolated sandstones in Upper Triassic deposits of the Auld Lang Syne basin of northwest Nevada, USA. Detrital zircon U-Pb data for 11 sandstone samples (3269 zircon U-Pb dates) were acquired via LA-ICP-MS at the University of Arizona LaserChron Center for 11 sandstone samples. Primary insights from the data are twofold: 1) The data provide information about sediment provenance and indicate that sediment of the Auld Lang Syne basin was primarily derived from near the ancestral Ouachita orogen of Texas and Oklahoma. Sediment was transported to the Auld Lang Syne basin by a Late Triassic transcontinental river system, recorded today by the Upper Triassic Chinle and Dockum Groups of the southern continental interior region. 2) The youngest detrital zircon dates in each age distribution provide estimates of maximum depositional age. Maximum depositional ages are consistent with Late Triassic (Norian) deposition in the Auld Lang Syne basin, an age previously constrained by sparse invertebrate fossil data.

This data release includes raw detrital zircon U-Pb data for isolated sandstones in Upper Triassic deposits of the Auld Lang Syne basin of northwest Nevada, USA. Detrital zircon U-Pb data for 11 sandstone samples (3269 zircon U-Pb dates) were acquired via LA-ICP-MS at the University of Arizona LaserChron Center for 11 sandstone samples. Primary insights from the data are twofold: 1) The data provide information about sediment provenance and indicate that sediment of the Auld Lang Syne basin was primarily derived from near the ancestral Ouachita orogen of Texas and Oklahoma. Sediment was transported to the Auld Lang Syne basin by a Late Triassic transcontinental river system, recorded today by the Upper Triassic Chinle and Dockum Groups of the southern continental interior region. 2) The youngest detrital zircon dates in each age distribution provide estimates of maximum depositional age. Maximum depositional ages are consistent with Late Triassic (Norian) deposition in the Auld Lang Syne basin, an age previously constrained by sparse invertebrate fossil data. This data release includes raw detrital zircon U-Pb data for isolated sandstones in Upper Triassic deposits of the Auld Lang Syne basin of northwest Nevada, USA. Detrital zircon U-Pb data for 11 sandstone samples (3269 zircon U-Pb dates) were acquired via LA-ICP-MS at the University of Arizona LaserChron Center for 11 sandstone samples. Primary insights from the data are twofold: 1) The data provide information about sediment provenance and indicate that sediment of the Auld Lang Syne basin was primarily derived from near the ancestral Ouachita orogen of Texas and Oklahoma. Sediment was transported to the Auld Lang Syne basin by a Late Triassic transcontinental river system, recorded today by the Upper Triassic Chinle and Dockum Groups of the southern continental interior region. 2) The youngest detrital zircon dates in each age distribution provide estimates of maximum depositional age. Maximum depositional ages are consistent with Late Triassic (Norian) deposition in the Auld Lang Syne basin, an age previously constrained by sparse invertebrate fossil data.

This laser ablation ICPMS U-Pb zircon data set supports stratigraphic, biostratigraphic and age interpretations of the of the fossil-plant-bearing El Gameño 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) for Late Triassic to Jurassic sedimentary rocks that don’t have precisely known absolute ages.

This laser ablation ICPMS U-Pb zircon data set supports stratigraphic, biostratigraphic and age interpretations of the of the fossil-plant-bearing El Gameño 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) for Late Triassic to Jurassic sedimentary rocks that don’t have precisely known absolute ages.

This Laser ablation ICPMS U-Pb detrital zircon data set supports mapping and stratigraphic interpretations of the Upper Devonian Ignacio Formation in southwestern Colorado (Silverton area). All samples were collected from a measured stratigraphic section called "Sultan Creek South" located at 37.710010 and -107.67530 (Evans and others, 2019). The Ignacio Formation was previously interpreted as Cambrian, but evidence that it is Devonian includes reexamined fossil data and detrital zircon U-Pb geochronology. The Ignacio Formation has a stratigraphic trend of detrital zircon ages shifting from a single ca. 1.7 Ga age peak to bimodal ca. 1.4 Ga and ca. 1.7 Ga age peaks, which represents local source-area unroofing history. Specifically, the upper plate of a Proterozoic thrust system (ca. 1.7 Ga Twilight Gneiss) was eroded prior to exposure of the lower plate (ca. 1.4 Ga Uncompahgre Formation). These results are a significant alternative interpretation of the geologic history of the southern Rocky Mountains.

This Laser ablation ICPMS U-Pb detrital zircon data set supports mapping and stratigraphic interpretations of the Upper Devonian Ignacio Formation in southwestern Colorado (Silverton area). All samples were collected from a measured stratigraphic section called "Sultan Creek South" located at 37.710010 and -107.67530 (Evans and others, 2019). The Ignacio Formation was previously interpreted as Cambrian, but evidence that it is Devonian includes reexamined fossil data and detrital zircon U-Pb geochronology. The Ignacio Formation has a stratigraphic trend of detrital zircon ages shifting from a single ca. 1.7 Ga age peak to bimodal ca. 1.4 Ga and ca. 1.7 Ga age peaks, which represents local source-area unroofing history. Specifically, the upper plate of a Proterozoic thrust system (ca. 1.7 Ga Twilight Gneiss) was eroded prior to exposure of the lower plate (ca. 1.4 Ga Uncompahgre Formation). These results are a significant alternative interpretation of the geologic history of the southern Rocky Mountains.

This dataset includes U-Pb detrital zircon age data for samples from the Ingleside and Lyons formations in north-central Colorado collected from Owl Canyon and Park Creek Reservoir, from the Molas and Hermosa formations in southwestern Colorado collected from Molas Pass, and from the Lykins formation and its equivalents along the Front Range and in southeastern Colorado. It accompanies publications 'The Permian-Triassic Transition in Colorado' published in Unfolding the Geology of the West: Geological Society of America Field Guide 44, and 'Detrital zircon geochronology of Pennsylvanian-Permian strata in Colorado: evidence for Appalachian-derived sediment and implications for the timing of Ancestral Rocky Mountains uplift' published in The Mountain Geologist.

This dataset includes U-Pb detrital zircon age data for samples from the Ingleside and Lyons formations in north-central Colorado collected from Owl Canyon and Park Creek Reservoir, from the Molas and Hermosa formations in southwestern Colorado collected from Molas Pass, and from the Lykins formation and its equivalents along the Front Range and in southeastern Colorado. It accompanies publications 'The Permian-Triassic Transition in Colorado' published in Unfolding the Geology of the West: Geological Society of America Field Guide 44, and 'Detrital zircon geochronology of Pennsylvanian-Permian strata in Colorado: evidence for Appalachian-derived sediment and implications for the timing of Ancestral Rocky Mountains uplift' published in The Mountain Geologist.