데이터셋 상세
미국
Luminescence and Radiocarbon data for: Geologic Map of the Sparta East, Sparta West, and parts of the Glade Valley and Whitehead 7.5-minute quadrangles, North Carolina and Virginia, and the epicentral area of the August 9, 2020, Mw 5.1 earthquake in Sparta, NC
New bedrock and surficial geologic mapping in the Blue Ridge of NW NC and SW VA covers the Sparta East, Sparta West, and parts of the Glade Valley and Whitehead 7.5-minute quadrangles and includes the epicentral area of the 9 August 2020 Mw 5.1 earthquake near Sparta, NC. Mapping documented (1) the co-seismic surface rupture from the 2020 earthquake and brittle structures in the bedrock; (2) the fault contact between the western Blue Ridge (wBR) and eastern Blue Ridge (eBR); (3) lithostratigraphy in the Lynchburg Group, Wills Ridge Formation, Ashe Metamorphic Suite (AMS) and Alligator Back Metamorphic Suite (ABMS); (5) the nature of the contact between Lynchburg Group, AMS and ABMS; and (4) surficial deposits. The wBR consists of Mesoproterozoic granitoid gneiss (1.3–1.0 Ga) intruded by the Neoproterozoic Striped Rock pluton (~740 Ma). These rocks are overprinted by a late Paleozoic greenschist facies foliation that intensifies into several anastomosing high-strain shear zones of the Fries fault zone; rocks within the shear zones are white-mica phyllonites to ultramylonites. Kinematic indicators consistently document top-to-NW thrust motion. To the southeast, the polydeformed eBR is juxtaposed over the wBR along the Gossan Lead fault, a ~1 km-wide shear zone. Lithostratigraphy in the eBR separates interlayered graphitic mica schists (Zlp), metagraywacke and graphitic schist (Zl), metaconglomerate and metagraywacke (Zlc), and metagabbro (Zlg) into the Lynchburg Group, Wills Ridge Formation. A SHRIMP U-Pb zircon age of ~455 Ma was obtained on a ~1 m thick metagabbro dike that intrudes metagraywacke in the Lynchburg Group. The Lynchburg Group rocks are separated from metaultramafic-bearing rocks of the AMS by an unnamed fault. The AMS consists of metagraywacke and schist (_Za), muscovite schist and metagraywacke (_Zas), metaconglomerate and metagraywacke (_Zac), amphibolite (_Zaa) and metaultramafic schists and rocks (_Zau and _Zaud). NE-SW trending structures dominate the eBR: relict S0 bedding, S1 foliations and intrafolial F1 folds are transposed into a regional S2 foliation (mean 063/52). Map-scale isoclinal F2 folds are overprinted by an S3/F3 crenulation. The structurally higher ABMS consists of pinstriped mica gneiss and schist (_Zab). The contact between the AMS and ABMS is a dextral shear zone. In the epicentral area, the Little River fault (~110/45) is mapped for ~4 km and similarly oriented brittle faults occur in the Bledsoe Creek valley up to 4 km to the NW. Manganese-coated, striated brittle faults and surfaces are common; manganese cemented breccias occur locally. Terrace deposits are mapped above the New River, Little River, Bledsoe Creek, and major tributaries. Terrace deposits above Bledsoe Creek in the epicentral area overlie a brittle fault and yield cosmogenic burial ages of ~500 Ka. Potential paleoliquefaction structures were identified at 4 locations. This report consists of a surficial and bedrock geologic map with cross sections, correlation of map units, and description of map units, and a GeMS level 3 geodatabase. Mapping was supported by the National Cooperative Geologic Mapping Program and Earthquake Hazards Program; a EDMAP Grant supported mapping by A. Lynn and K. G. Stewart.
데이터 정보
연관 데이터
Data Release for Luminescence:Paleoseismic liquefaction associated with Holocene earthquakes on the Wallula Fault zone, Southeast Washington, USA
공공데이터포털
Observations of widespread liquefaction and stratigraphic and structural relationships in a trench across an ambiguous scarp are used to constrain the timing of Holocene earthquakes on the northwest-striking Wallula fault zone in southeast Washington and Oregon. Additional observations and age constraints from OSL analysis of samples collected from large-scale liquefaction features that crosscut the Mount St Helens J tephra (13.8-13.7 ka) exposed at a nearby outcrop suggest up to 3 Holocene regional liquefaction events, any of which were likely triggered by seismic shaking sourced from either the Wallula fault and/or faults of the Yakima fold and thrust belt. Our observations provide plausible evidence supporting that the scarp formed during the M6 1936 Milton-Freewater earthquake. In addition, stratigraphic relationships observed in this study indicate that the end of the Missoula Floods in the southeast Washington region occurred sometime between 13.8–13.5 cal. k.y. B.P., approximately 1,000 years earlier than prior estimates.
Luminescence and Radiocarbon data for: Geologic map of the Big Levels Quadrangle, Virginia
공공데이터포털
At the Rockbridge Stone Products sand and gravel open pit mine along Loves Run, two Optically Stimulated Luminescence samples from an f2 fan deposit yielded dates from ca. 157 to 139 ka (Carter and others, 2017). These two ages were used to define the Pleistocene map units within the quad.
DATA RELEASE for LUMINESCENCE: Mid to Late Quaternary Geomorphic and Paleoseismic Event History, Cheraw Fault, Colorado
공공데이터포털
Despite its subdued expression and isolated location within the Great Plains of southeastern Colorado, the 80-km-long Cheraw fault may be one of the most active faults in North America east of the Southern Rocky Mountains. We present geomorphic analyses, geochronology, and paleoseismic trenching data to 1) document the rupture history of the ~45-km-long southwestern section of the Cheraw fault over the past ~19 ka, and 2) evaluate slip-rate changes for the entire fault over the past ~200 ka. Results from new trenches excavated at the Old Ranch site show evidence of four surface-rupture events since ~19 ka, each with an average vertical displacement of 0.75 m. An additional event is likely only slightly older than ~19 ka. Evidence for relatively small displacements at and near the Old Ranch site suggests that most of these earthquakes were M 7 or less and likely did not rupture the full length of the Cheraw fault. Since ~19 ka, the average slip rate is ~0.16 mm/yr near the Old Ranch site with an average interevent time of 3 - 5 kyr. New geochronologic data for mid- to late Quaternary geomorphic surfaces cut by the Cheraw fault imply rapid incision by local Arkansas River tributaries from ~145 ka to ~100 ka. Maximum vertical offsets of 7 to 9 m for these surfaces indicate that from ~19 to >200 ka the average slip rate was no greater than ~0.03 mm/yr. The accelerated slip rate since ~19 ka suggests a possible response to rapid erosional unloading and/or a limited late Cenozoic, <40 kyr, paleoseismic history for the Cheraw fault.
U-Pb detrital zircon data for: lower Paleozoic sedimentary rocks near Silverton, CO USA
공공데이터포털
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.
Seismic data for study of shallow mountain bedrock limits seepage-based headwater climate refugia, Shenandoah National Park, Virginia: U.S. Geological Survey data release
공공데이터포털
A combination of long-term daily temperature records and depth to bedrock measurements were used to parametrize one-dimensional models of shallow aquifer vertical heat transport in Shenandoah National Park, VA, USA. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employed rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting coldwater-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park. The methods are fully documented in the associated journal article, Briggs, M.A., J.W. Lane, C.D. Snyder, E.A. White, Z.C. Johnson, D.L. Nelms, and N.P. Hitt, 2017, Shallow mountain bedrock limits seepage-based headwater climate refugia, Limnologica, https://dx.doi.org/10.1016/j.limno.2017.02.005. This Data Release includes seismic data collected as part of the study.
Data Release for Luminescence: Floodplain Sediment Storage Timescales of the Laterally Confined Meandering Powder River, U.S.A
공공데이터포털
The following report summarizes the dating results from the. Within this report, we detail the methodology used to determine the storage time distribution for a 17 km length of Powder River in Montana, U.S.A. by the age distribution of eroded sediment. This data is used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement, equivalent dose determination, and dating-related calculations. We recommend that this report be included as the supplementary material for any publication(s) that use the ages within this report. This version supersedes all previous age estimates and reports.
Data Release for Luminescence: Floodplain Sediment Storage Timescales of the Laterally Confined Meandering Powder River, U.S.A
공공데이터포털
The following report summarizes the dating results from the. Within this report, we detail the methodology used to determine the storage time distribution for a 17 km length of Powder River in Montana, U.S.A. by the age distribution of eroded sediment. This data is used by the USGS Luminescence Geochronology Laboratory to obtain ages including sample preparation methods, luminescence measurement, equivalent dose determination, and dating-related calculations. We recommend that this report be included as the supplementary material for any publication(s) that use the ages within this report. This version supersedes all previous age estimates and reports.
Data Release for Luminescence: OSL Data and Ages in support of the Surficial Geology and Quaternary Fault Map of the Las Vegas Valley, Clark County, Nevada
공공데이터포털
The data release includes 35 new luminescence ages and 3 new radiocarbon ages. The new age data further brackets the ages of the Las Vegas basin Quaternary stratigraphy and provide new constraints on the timing of Quaternary fault activity.
Data Release for Luminescence: OSL Data and Ages in support of the Surficial Geology and Quaternary Fault Map of the Las Vegas Valley, Clark County, Nevada
공공데이터포털
The data release includes 35 new luminescence ages and 3 new radiocarbon ages. The new age data further brackets the ages of the Las Vegas basin Quaternary stratigraphy and provide new constraints on the timing of Quaternary fault activity.
Datasets documenting limited evidence of Late Pleistocene tectonic surface deformation in the Eastern Tennessee Seismic Zone, Tennessee, USA
공공데이터포털
These datasets provide lineament mapping, catchment-averaged metrics of hypsometry and channel steepness, field observations, and a structure from motion model and orthomosiac photograph of sites in the Eastern Tennessee seismic zone in eastern Tennessee, USA. The lineament mapping contains linework of possible neotectonic features mapped from 1-m lidar data. Catchment-averaged metric of hypsometry and channel steepness are for selected catchments along the Powell River in northern Tennessee. Field observations provides points and notes of reconnaissance fieldwork to describe and document select lineaments in the Powell River and Oak Ridge areas. The structure from motion model and orthomosiac photograph document the Little River exposure described in previous studies. These datasets are associated with the manuscript: Thompson Jobe, J. A., R. W. Briggs, R. D. Gold, L. Bauer, and C. Collett (in review). Limited evidence for Late Pleistocene tectonic surface deformation in the Eastern Tennessee Seismic Zone, USA.
목록