This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data, mineral chemistry, and monazite and xenotime geochronology for Proterozoic rocks in the Needle Mountains of southwestern Colorado and for Proterozoic rocks sampled from drill cores from Colorado, North Dakota, Nevada, Wyoming, Montana, and Nebraska. Samples from the Needle Mountains were collected in order to constrain the polyphase tectonic evolution of the area. Additionally, multi-scale compositional mapping, petrologic modeling and in-situ geochronology constrain the pressure-temperature-time paths from basement gneisses and quartzites. Drill core samples are part of a larger characterization of the age and geochemical character of basement terranes in the United States.

This U.S. Geological Survey (USGS) data release provides monazite and xenotime geochronology from Proterozoic rocks collected from outcrop in central Colorado and whole rock isotope geochemistry, and zircon and monazite geochronology from a Proterozoic rock sampled from a drill core from western Colorado. The drill core sample was collected from the 1 Paradox Valley injection core near Bedrock, CO at a depth of 4,755-4,765 m below the surface. The samples were in order to constrain the age, provenance, metamorphic history, and geochemical character of basement terranes in Colorado.

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 part of a larger characterization of the age and geochemical character of basement terranes in the United States.

This U.S. Geological Survey (USGS) data release includes whole-rock major, trace, and rare earth element geochemical data, whole-rock and mineral Nd-Pb-Sr isotopic data collected by thermal ionization mass spectrometry (TIMS), and uranium-lead isotopic data collected by Sensitive High Resolution Ion Microprobe-Reverse Geometry (SHRIMP-RG) methods that characterize the Mountain Pass Rare Earth Element deposit, associated Mesoproterozoic igneous rocks, and their Paleoproterozoic host rocks in Arizona, California, and Nevada. SHRIMP-RG data were collected between 2013 and 2018. Sample collection and whole-rock geochemistry were carried out between 1981 and 2015.

This U.S. Geological Survey (USGS) data release includes whole rock geochemical and isotopic data, and uranium-lead isotopic data collected by both Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Sensitive High Resolution Ion Microprobe-Reverse Geometry (SHRIMP-RG) methods for rocks in Colorado, Wyoming, Utah, and New Mexico.

This U.S. Geological Survey (USGS) data release includes whole rock geochemical and isotopic data, and uranium-lead isotopic data collected by both Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Sensitive High Resolution Ion Microprobe-Reverse Geometry (SHRIMP-RG) methods for rocks in Colorado, Wyoming, Utah, and New Mexico.

In 2024, the United States Geological Survey (USGS) compiled rock properties data from the USGS Core Research Center's (CRC) database for the Southwestern Wyoming Province and adjoining areas to better characterize the potential hydrocarbon sources and reservoirs in the area. Data from 53 wells were collected from data analysis results located in the CRC database. These data are derived from a combination of USGS and non-USGS laboratory analyses, with samples provided over several decades by researchers who accessed the CRC collection. The compiled data are from pre-Cretaceous Formations in the Southwestern Wyoming Province area. For each well, accompanying metadata details the sample sources, analytical methods, and quality considerations to aid in scientific analysis and public use.

This U.S. Geological Survey (USGS) data release presents U-Th-Pb concentrations, isotopic ratios, and geochronologic data collected by thermal ionization mass spectrometry (TIMS) for Proterozoic igneous and metamorphic rocks of the Mojave Province, California and Nevada. Sample and data collection occurred by 1984 and 1990.

In 2021 the United States Geological Survey (USGS) sampled the lower part of the Upper Cretaceous Lewis Shale in the eastern part of the Southwestern Wyoming Province to better characterize its petroleum source rock potential for an upcoming resource assessment. Ninety-five samples from 24 wells were collected from well cuttings of the lower part of the Lewis Shale stored at the U.S. Geological Survey Core Research Center in Lakewood, Colorado. The selected wells are located near the shallow margins of the basin to obtain samples that were not subjected to the effects of deep burial and subsequent organic carbon loss due to thermal maturation as described by Daly and Edman (1987) (fig, 1). The sample intervals were selected based on high gamma ray responses that Pyles and Slatt (2007) interpreted to be organic-rich condensed sections. Special emphasis was given to the Asquith marker bed which represents the maximum transgression of the Lewis Shale (Pasternack, 2005) (fig. 2).

In 2021 the United States Geological Survey (USGS) sampled the lower part of the Upper Cretaceous Lewis Shale in the eastern part of the Southwestern Wyoming Province to better characterize its petroleum source rock potential for an upcoming resource assessment. Ninety-five samples from 24 wells were collected from well cuttings of the lower part of the Lewis Shale stored at the U.S. Geological Survey Core Research Center in Lakewood, Colorado. The selected wells are located near the shallow margins of the basin to obtain samples that were not subjected to the effects of deep burial and subsequent organic carbon loss due to thermal maturation as described by Daly and Edman (1987) (fig, 1). The sample intervals were selected based on high gamma ray responses that Pyles and Slatt (2007) interpreted to be organic-rich condensed sections. Special emphasis was given to the Asquith marker bed which represents the maximum transgression of the Lewis Shale (Pasternack, 2005) (fig. 2).