This data release contains geochemical data for volcanic tephra from Kīlauea Volcano, Hawaiʻi, sampled between March 19 and April 16, 2008.

This data release contains geochemical data for volcanic tephra from Kīlauea Volcano, Hawaiʻi, sampled between March 19 and April 16, 2008.

Zircon geochronology of Torok and Nanushuk Formations sandstones at Slope Mountain and a Seabee Formation tephra deposit at Ninuluk Bluff, central North Slope, Alaska, Raw Data File 2024-33, presents LA-ICPMS and CA-ID-TIMS U-Pb data for five DZ samples collected from a well-known exposure at Slope Mountain, which is one of the few localities where the transition between mid-Cretaceous Torok and Nanushuk Formations is preserved in outcrop. We also report new U-Pb tephra zircon data from basal Seabee Formation at Ninuluk Bluff, a key-and similarly rare-site where the transition between Late Cretaceous Nanushuk strata and overlying Seabee crops out. These tandem-dated samples were collected during summer field seasons in 2018 and 2019 as part of DGGS's North Slope and Brooks Range foothills basin analysis program. The new zircon geochronology results from Slope Mountain and Ninuluk Bluff are documented and permanently archived herein. These data and report are available from the DGGS website: http://doi.org/10.14509/31152.

The Kluane Ranges, located in southwest Yukon, are underlain by Late Paleozoic to Late Triassic volcanic and sedimentary rocks assigned to Wrangellia. Bedrock mapping completed within the White River area indicates Wrangellian rocks underwent several phases of deformation between Late Triassic and Miocene time. Middle Triassic marine, fine-grained sedimentary rocks are preserved in grabens where they are overlain by basal conglomerates and breccias of the Nikolai formation. The grabens are related to uplift associated with the deposition of Nikolai formation flood basalts and intrusion of ultramafic bodies. Late Jurassic to Early Cretaceous compression resulted in structural stacking of older rocks and northeast- and southwest-verging overturned folds. Latest (?) Cretaceous to Miocene dextral strike-slip along the Denali fault system led to the formation of steeply dipping faults, extensional and compressional basins and refolding of older regional scale folds. Reactivation of Jura-Cretaceous faults also occurred at this time. An enigmatic pre-Middle Triassic deformation event is believed to be preserved locally in rocks of the Hasen Creek Formation.

U-Pb ages and concentrations of selected trace elements were analyzed in zircon crystals from nine samples of Cenozoic igneous rocks collected near Tonopah, Nevada. U-Pb ages were obtained from four samples, and trace element analyses were obtained from both the dated samples and an additional five samples.

Tephra samples from the Kulanaokuaiki Tephra Member (400 to 1000 C.E.) of the Uwēkahuna Ash (200 B.C.E. to 1000 C.E.) were sampled from Kīlauea volcano, Island of Hawai‘i. Samples were analyzed by dynamic imaging analysis using Microtrac CAMSIZER P4 and X2 instruments for grain shape and Anton nitrogen pycnometer instruments for density in the U.S. Geological Survey - Hawaiian Volcano Observatory tephra lab. Componentry analysis was done by hand through point-counting and identification of >200 individual clasts. Data shown is for number of grains picked in each category. Grain shape parameter means of sphericity, aspect ratio, convexity, transparency, compactness, and Krumbein roundness are reported, as well as for half phi grain size bins starting at 4, 3, 2, 1, 0, -1, -2, -3, and -4 phi. Additional methodology and details are outlined in Nalesnik (2025). This data release includes site and sample metadata, followed by deposit componentry, density, and grain shape.

Between the Cretaceous granitic rocks (Hake Batholith on the west; Cassiar Batholith to the east) are three belts of metamorphic rocks, collectively part of Yukon-Tanana terrane. These are remnants of oceanic and continental volcanic arcs, and marginal basin sediments of Early to mid-Paleozoic age. At the head of Borden Creek are thick carbonate and andesitic volcanic rocks correlated with Klinkit Group. The Ram Creek fault and Hidden Lake fault are not exposed but deduced to be steeply dipping brittle structures with northeastward thrust or transpressional offset, based upon more complete exposure to the southeast in 105B/3 map area. The former is likely of Cretaceous age; the latter was active between mid-Permian and Early Jurassic time.

This dataset includes radiocarbon ages, wavelength dispersive X-ray fluorescence (WD-XRF) major-oxide and trace-element whole-rock analyses, and glass, olivine, and pyroxene analyses by electron microprobe (EPMA) of spatter and lava samples from the summit and Southwest Rift Zone of Kīlauea volcano, Island of Hawaiʻi. All of the radiocarbon ages were analyzed by DirectAMS in Bothell, Washington, USA and are from the 1823 CE lava flow in the Southwest Rift Zone (using the methods of Tate and others, 2023). Whole-rock chemical analyses were performed at both the Hamilton Analytical Laboratory at Hamilton College in Clinton, New York, USA and Washington State University GeoAnalytical Lab in Pullman, Washington, USA (using the methods of Johnson and others, 1999). Glass chemical analyses were performed at the U.S. Geological Survey in Menlo Park, California, USA and the University of Hawai‘i at Mānoa, Mānoa, Hawaii, USA. All olivine and pyroxene chemical analyses were performed at the University of Hawai‘i at Mānoa, Mānoa, Hawaii, USA (using the methods of Donovan and Tingle, 1996). This data set was collected and used for the interpretations in Tonato and others (2025). Donovan, J.J., and Tingle, T.N., 1996, An improved mean atomic number background correction for quantitative microanalysis: Microscopy and Microanalysis, v. 2, p. 1–7, https://doi.org/10.1017/S1431927696210013. Johnson, D.M., Hooper, P.R., and Conrey, R.M., 1999, XRF analysis of rocks and minerals for major and trace elements on a single low dilution Li-tetraborate fused bead: JCPDS-International Centre for Diffraction Data, p. 843–867. Tate, A.M.,Heile, J., Giacomo, J., and Zoppi, U., 2023, Status report: A decade of traditional radiocarbon dating applications by DirectAMS: Nuclear Instruments and Methods in Physics Research Sections B: Beam Interactions with Materials and Atoms, v. 537, p. 23–28, https://doi.org/10.1016/j.nimb.2023.01.013. Tonato, A., Shea, T., Downs, D.T., and Kelfoun, K., 2025, Rapid emplacement of the 1823 CE Keaīwa lava flow from the Great Crack in the Southwest Rift Zone of Kīlauea volcano: Journal of Volcanology and Geothermal Research.

Regional-scale thrust faults in the Klondike District separate major lithologic units that include medium-grade metamorphic rocks of the Upper Permian Klondike Schist and middle to late Paleozoic Finlayson (Nasina) assemblage, as well as relatively low-grade greenstone and ultramafic rocks of the Slide Mountain terrane. These units were emplaced in the Jurassic as a series of kilometre-scale stacked thrust slices that are locally separated by additional ultramafic slices. A distinctive set of post-metamorphic compressional structures related to thrusting, particularly a set of ductile recumbent folds and associated spaced cleavage, is preserved in all thrust slices and is well developed near bounding faults. In carbonaceous units within the Klondike Schist, spatially associated with some thrusts, carbonaceous material is locally concentrated along the thrust-related spaced cleavage. Thrust-related fabrics are overprinted by kink-folding that locally affects the Finlayson assemblage, but is mainly developed in Klondike Schist. Gold-bearing veins appear confined to Klondike Schist and were emplaced in local sites of extension controlled principally by axial surfaces of these kink folds.