Drew T. Downs May Sas 20260317 spreadsheet Reston, VA U.S. Geological Survey https://doi.org/10.5066/P1CW2KCM Drew T. Downs May Sas 2026 publication This dataset includes major-, minor-, and trace-element analyses by electron probe microanalysis (EPMA) and trace-element analyses by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of olivine, plagioclase, clinopyroxene, and orthopyroxene minerals from scoria and lava samples from the Kamakaiʻa Hills of the Southwest Rift Zone of Kīlauea volcano, Island of Hawaiʻi, USA. Chemical analyses by EPMA were performed at the U.S. Geological Survey in Moffett Field, California, and LA-ICP-MS chemical analyses were performed at Western Washington University in Bellingham, Washington. The data were collected as part of volcanic research on the Kamakaiʻa Hills of the Southwest Rift Zone of Kīlauea volcano, Island of Hawaiʻi. Samples were used to quantitatively measure major-, minor-, and trace-element by electron microprobe (EPMA) and trace-element abundances by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) on the minerals of clinopyroxene, orthopyroxene, plagioclase, and olivine. 19690101 20250101 ground condition Complete None planned -155.38920 -155.34980 19.30950 19.21710 USGS Thesaurus Volcanology Volcanic Activity Chemical Analyses Lava Flow Tephra Volcanic Fissure Clinopyroxene Orthopyroxene Plagioclase Olivine Volcanology USGS Metadata Identifier USGS:68da9f7ad4be021b36eb5f6d Geographic Names Information System (GNIS) Island of Hawaiʻi Kīlauea Southwest Rift Zone Kamakaiʻa Hills None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Drew T. Downs U.S. Geological Survey - Hawaiian Volcano Observatory Research Geologist mailing and physical

1266 Kamehameha Avenue, Suite A-8

Hilo Hawaii 96720 US 808-967-7328 ddowns@usgs.gov Western Washington University No formal attribute accuracy tests were conducted. No formal logical accuracy tests were conducted. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted. No formal positional accuracy tests were conducted. Mineral (clinopyroxene, orthopyroxene, plagioclase, and olivine) compositions from the Kamakaiʻa Hills flow field were analyzed on polished thin sections using a five spectrometer JEOL Hyperprobe JXA-8530F+ electron microprobe at the U.S. Geological Survey in Menlo Park, California. Secondary standards were routinely measured to assess data quality and monitor for drift. For all EPMA data, X-ray intensities were converted to concentrations using standard ZAF corrections based on atomic number (Z), absorption (A), and fluorescence excitation (F). Analyses with totals <98.5 and >101 wt. % were rejected. Spot analyses of pyroxene and olivine were performed using an accelerating voltage of 20 keV, a 15 nA beam current, a 5 µm beam diameter, and count times of 20 seconds (Si, Mg, and Fe), 40 seconds (Ca, Mn, Al, Na, Ti, and Cr), and 60 seconds (Ni). San Carlos Olivine USNM 111312/444 and Clinopyroxene PX-1 (Jarosewich and others, 1980) were analyzed as unknowns to monitor for analytical drift. Spot analyses of plagioclase were performed using an accelerating voltage of 15 keV, a 10 nA beam current, a 5 µm beam diameter, and count times of 10 seconds (Na and K), 20 seconds (Si, Al, and Ca), and 40 seconds (Fe, Mg, Sr, and Ba). Crystal Bay Bytownite, Orthoclase OR-1A, and Strontianite (Jarosewich and others, 1980) were analyzed as unknowns to monitor for analytical drift. Jarosewich, E., Nelen, J.A., and Norberg, J.A., 1980, Reference samples for electron microprobe analysis. Geostandards Newsletter, v. 4, p. 43–47, https://doi.org/10.1111/j.1751-908X.1980.tb00273.x. 20250101 Trace element mineral compositions of crystals were measured on an Agilent 7900 quadruple ICP-MS equipped with a RESOlution-SE 193 nm ArF excimer laser ablation introduction system at Western Washington University in Bellingham, Washington. Ablation conditions include a 24 μm diameter spot size, laser repetition rate of 10 Hz, and a fluence of 2 J/cm2. The carrier gas, He, was set at a flow rate of 400 mL/min and mixed with 1000 mL/min of Ar. The masses collected constitute 7Li, 23Na, 25Mg, 27Al, 29Si, 39K, 43Ca, 45Sc, 47Ti, 51V, 53Cr, 55Mn, 57Fe, 59Co, 60Ni, 65Cu, 66Zn, 85Rb, 88Sr, 89Y, 90Zr, 93Nb, 137Ba, and 153Eu. The SRM glass NIST-610 was used for tuning, USGS basaltic glass GSD-1G was used as the calibration standard, and USGS basaltic glasses GSE-1G, BCR-2G, and BHVO-2G were used as secondary standards and compared to GeoReM preferred concentrations (Jochum and others, 2005). Fractionation was monitored using 238U/232Th and adjusted to be ~1. Interferences for oxides were monitored using 248ThO/232Th and were <0.09%, and interferences for doubly-charged ions were monitored using 44Ca++/44Ca+ and were <0.11%. Data were processed using the data reduction software GLITTER (Griffin and others, 2008) with Mg and Al as the internal standards for ferromagnesian phases and feldspar, respectively. Griffin, W.L., Powell, W.J., Pearson, N.J., and O’Reilly, S.Y., 2008, GLITTER: Data reduction software for laser ablation ICP-MS, in Sylvester, P.J., ed., Laser Ablation ICP-MS in the Earth Sciences: Current Practices and Outstanding Issues, Short Course Series, Mineralogical Association of Canada, p. 308–311. Jochum, K.P., Willbold, M., Raczek, I., Stoll, B., and Herwig, K., 2005, Chemical Characterisation of the USGS Reference Glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G Using EPMA, ID-TIMS, ID-ICP-MS and LA-ICP-MS: Geostandards and Geoanalytical Research, v. 29, p. 285–302, https://doi.org/10.1111/j.1751-908X.2005.tb00901.x. 20250101 Point Point Universal Transverse Mercator 5 0.9996 -153.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 meters North_American_Datum_1983 GRS 1980 6378137.0 298.257222101 The data dictionary for entity and attribute data was constructed for EPMA data, LA-ICP-MS data, EPMA standards data, and LA-ICP-MS standards data from laboratory reports. The data dictionary is provided on the Description of Terms tab on the excel spreadsheet. U.S. Geological Survey GS ScienceBase mailing address

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. All trademarks and trade names are the property of their respective owners. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P1CW2KCM None 20260317 Drew T. Downs U.S. Geological Survey - Hawaiian Volcano Observatory Research Geologist mailing and physical

1266 Kamehameha Avenue, Suite A-8

Hilo Hawaii 96720 US 808-967-7328 ddowns@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998