Isotopic compositions (87Sr/86Sr, 143Nd/144Nd, 176Hf/177Hf, 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb) and major oxide and trace element concentrations of Quaternary basalts, hawaiites, mugearites, benmoreites, and trachytes from northern Harrat Rahat, Kingdom of Saudi Arabia.

The data are the results of mass spectrometer experiments to measure 40Ar/39Ar ages of groundmass and mineral separates from volcanic rocks in northern Harrat Rahat, Kingdom of Saudi Arabia. The data were collected using a MAP216 noble gas mass spectrometer at the USGS facility in Menlo Park, Calif. These data were collected as part of a collaborative study conducted by the U.S. Geological Survey and Saudi Geological survey to assess the volcanic and seismic hazards associated with the northern Harrat Rahat volcanic field.

This dataset includes X-ray fluorescence (XRF) major-oxide and trace-elements analysis and inductively coupled plasma-mass spectrometry (ICP-MS) trace-element analysis of Cenozoic, mainly Quaternary, basalts, hawaiites, mugearites, benmoreites, and trachytes from the northern third of the Harrat Rahat volcanic field and surrounding area in the Kingdom of Saudi Arabia. These samples were collected and analyzed to support geologic mapping of the volcanic field and reconstruction of its volcanic history as part of a collaborative project between the Saudi Geological Survey (SGS) and the U.S. Geological Survey (USGS), supported by the Kingdom of Saudi Arabia. Chemical analyses were performed at the GeoAnalytical Laboratory of Washington State University in Pullman, Washington, USA under contract with the USGS. Secondary minerals consisting mainly of zeolites, sulfates, and carbonates are present in pores in many of the collected rocks, and their abundances were reduced or eliminated prior to chemical analysis by hand-picking, followed by soaking rock chips in hot deionized water, and then extended ultrasonication in deionized water. Chemical compositions were further screened to exclude samples with original analytical totals of less than 94 weight percent, yielding a total of 691 samples with acceptable analyses presented in this data release, along with their sample names (called "Stations"), locations as easting and northing (in WGS1984 UTM Zone 37N), stratigraphic abbreviations (called "StratCode") defined in an associated geologic map, XRF and ICP-MS analyses, and other published references.

This dataset includes X-ray fluorescence (XRF) major-oxide and trace-elements analysis and inductively coupled plasma-mass spectrometry (ICP-MS) trace-element analysis of Cenozoic, mainly Quaternary, basalts, hawaiites, mugearites, benmoreites, and trachytes from the northern third of the Harrat Rahat volcanic field and surrounding area in the Kingdom of Saudi Arabia. These samples were collected and analyzed to support geologic mapping of the volcanic field and reconstruction of its volcanic history as part of a collaborative project between the Saudi Geological Survey (SGS) and the U.S. Geological Survey (USGS), supported by the Kingdom of Saudi Arabia. Chemical analyses were performed at the GeoAnalytical Laboratory of Washington State University in Pullman, Washington, USA under contract with the USGS. Secondary minerals consisting mainly of zeolites, sulfates, and carbonates are present in pores in many of the collected rocks, and their abundances were reduced or eliminated prior to chemical analysis by hand-picking, followed by soaking rock chips in hot deionized water, and then extended ultrasonication in deionized water. Chemical compositions were further screened to exclude samples with original analytical totals of less than 94 weight percent, yielding a total of 691 samples with acceptable analyses presented in this data release, along with their sample names (called "Stations"), locations as easting and northing (in WGS1984 UTM Zone 37N), stratigraphic abbreviations (called "StratCode") defined in an associated geologic map, XRF and ICP-MS analyses, and other published references.

The Yellowstone Plateau Volcanic field consists of lavas from the last two million years. The most recent volcanic units are the Central Plateau Member and the older Upper Basin Member rhyolites (Christiansen, 2001). Investigations into the elemental and isotopic composition of these lavas can provide insight into the recent volcanic history of the different eruptive episodes and provide constraints on the hydrothermal fluid compositions that result from water-rock interactions occurring at depth within the hydrothermal system. In this Data Release, twenty-one samples of Yellowstone rhyolite samples from Upper Basin and Central Plateau Member lava flows were analyzed for major and trace element concentrations and strontium isotopic compositions. Analyzed samples include recently collected samples along with samples from the rock collection of Robert L. Christiansen (Robinson and others, 2021). This data was collected to constrain models of fluid-rock interaction of Yellowstone’s hydrothermal system. Christiansen, R.L., 2001, The Quaternary and Pliocene Yellowstone Plateau Volcanic Field of Wyoming, Idaho, and Montana. U.S. Geological Survey Professional Paper 729-G, 120 p. Robinson, J.E., McConville, E.G., Szymanski, M.E., and Christiansen, R.L., 2021, Yellowstone Sample Collection - database: U.S. Geological Survey data release, https://doi.org/10.5066/P94JTACV.

The Yellowstone Plateau Volcanic field consists of lavas from the last two million years. The most recent volcanic units are the Central Plateau Member and the older Upper Basin Member rhyolites (Christiansen, 2001). Investigations into the elemental and isotopic composition of these lavas can provide insight into the recent volcanic history of the different eruptive episodes and provide constraints on the hydrothermal fluid compositions that result from water-rock interactions occurring at depth within the hydrothermal system. In this Data Release, twenty-one samples of Yellowstone rhyolite samples from Upper Basin and Central Plateau Member lava flows were analyzed for major and trace element concentrations and strontium isotopic compositions. Analyzed samples include recently collected samples along with samples from the rock collection of Robert L. Christiansen (Robinson and others, 2021). This data was collected to constrain models of fluid-rock interaction of Yellowstone’s hydrothermal system. Christiansen, R.L., 2001, The Quaternary and Pliocene Yellowstone Plateau Volcanic Field of Wyoming, Idaho, and Montana. U.S. Geological Survey Professional Paper 729-G, 120 p. Robinson, J.E., McConville, E.G., Szymanski, M.E., and Christiansen, R.L., 2021, Yellowstone Sample Collection - database: U.S. Geological Survey data release, https://doi.org/10.5066/P94JTACV.

Mineral compositions are reported for Quaternary volcanic rocks of the Matan volcanic center, northern Harrat Rahat, Saudi Arabia. Compositions were measured by wavelength-dispersive methods with the 5-spectrometer JEOL-8900 electron microprobe at the USGS facility in Menlo Park, California; background-corrected X-ray intensities were reduced to oxide weight concentrations with the JEOL proprietary version of the CITZAF reduction schema. These results are part of a collaborative study by the U.S. Geological Survey and Saudi Geological survey to assess the volcanic and seismic hazards associated with the northern Harrat Rahat volcanic field.

The Harrat Rahat volcanic field, located in the west-central part of the Kingdom of Saudi Arabia, is the largest of 15 harrats (Arabic for 'volcanic field') hosted within the Arabian plate. Harrat Rahat is 50 to 75 km wide (east-west) and 300 km long (north-south), covering an area of approximately 20,000 square kilometers and encompassing more than 900 observable vents. The overall map area and its dataset show the volcanic geology of the northern part (about 3,340 square kilometers) of Harrat Rahat, at a scale of 1:75,000. Two additional map areas and their feature classes highlight areas of interest at 1:25,000 scale. Northern Harrat Rahat is of interest owing to the location of the city of Al-Madinah Al-Munawarah (hereafter, referred to as Al-Madinah), which sits atop (and is recently expanding over) the north end of the volcanic field. Al-Madinah is home to more than 1.5 million residents, and the city experiences an additional influx of approximately 3 million pilgrims annually. The downtown area of Al-Madinah is less than 8 km from lava flows of the only confirmed historical eruption (unit bla; eruptive stage 1), which occurred in 1256 C.E.

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The data are the results of mass spectrometer experiments to measure 40Ar/39Ar ages of sanidine crystals hosted in Yellowstone rhyolites. The data were collected using a MAP216 noble gas mass spectrometer and a Nu Noblesse noble gas mass spectrometer at the USGS facility in Menlo Park, Calif.