Geologic dating

used for all methods of dating geologic (or archaeologic) materials, including both absolute dating methods (yielding numerical ages) relative dating methods (for determining the relative order of geologic events).

10 results listed by similarity [list alphabetically]
Geochemistry of sediment and organic matter in drainages burned by the Altas and Nuns wildfires in October 2017 and of nearshore seabed sediment in north San Francisco Bay from March to April 2018

Fine-grained sediment was collected from the banks of Napa River, Sonoma Creek, and tributaries in March 2018 and from shallow nearshore areas of the northern reach of San Francisco Bay in April 2018. Bulk sediment was dated using activities of short-lived cosmogenic radionuclides (beryllium-7, cesium-137, and lead-210). Contents of potentially toxic metals and source-rock-indicative elements, including rare earth elements, were quantified in the fine fraction of sediment (particles less than 0.063 mm ...

Geochemical and isotopic compositions of stream sediment, parent rock, and nearshore sediment from southwest Puerto Rico, April 2017-June 2018

Geochemical and isotopic compositions were determined in stream sediment and parent rocks collected in April 2017 and June 2017 and in nearshore sediment collected bimonthly in sediment traps from May 2017 to June 2018 in the coastal zone and 12 drainages of southwest Puerto Rico: Rio Loco, Yauco, Guayanilla, Macana, Tallaboa, Matilde, Portugues, Bucana, Inabon, Jacaquas, Descalabrado, and Coamo. Geochemical compositional data include: a) total contents of major, minor, trace, and rare earth elements in the ...

Geophysical properties, geochronologic, and geochemical data of sediment cores collected from San Pablo Bay, California, October 17-20, 2016

Geophysical properties (P-wave velocity, gamma ray density, and magnetic susceptibility), geochronologic (radiocarbon, excess Lead-210, and Cesium-137), and geochemical data (organic carbon content and 60 element contents) are reported for select vibracores collected aboard the S/V Retriever October 17-20, 2016, in San Pablo Bay, California. Geophysical properties were measured with a Geotek Multi-Sensor Core Logger (MSCL). Radiocarbon was measured by accelerator mass spectrometry (AMS). Excess Lead-210 and ...

Geochemistry of fine-grained sediment in Bellingham Bay, Nooksack River, and small creeks from June 2017 to September 2019

Elemental compositions are reported for the fine fraction of surface sediments from Bellingham Bay (June 2017 and March 2019) and in the fine fraction of streambank sediment from the Nooksack River (September 2017, March 2019, September 2019), Squalicum Creek (March and September 2019), Whatcom Creek (March and September 2019), and Padden Creek (March and September 2019). Major oxide percentages are reported in Nooksack River fine sediment collected in September 2017. Ancillary data for sediment collected ...

Geochemistry of surface sediment and sediment cores in Bellingham Bay, Whatcom County, Washington, in February 2020

Geochemical data are reported for surface sediments and long sediment cores from Bellingham Bay, Whatcom County, Washington, collected in early February 2020 after flood conditions on the Nooksack River. Data include total organic carbon content (TOC), carbonate content (CaCO3), ratios of stable carbon 13/12 isotopes (d13C), ratios of total carbon to total nitrogen (C:N), short-lived cosmogenic radionuclide activities (Beryllium-7, Cesium-137, and excess Lead-210), and elemental chemistry.

Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) in watershed soil and reef sediment at Olowalu, Maui, 2022

Seventy six parent and alkylated polycyclic aromatic compounds, including polycyclic aromatic hydrocarbons (PAHs), were quantified in watershed and reef sediment from Olowalu, Maui, in February 2022 to explore urban and wildfire effects. Sample locations and total organic carbon contents (OC) are available in the accompanying file OlowaluWatershedReef2022_compositions.csv.

Elemental chemistry, radionuclides, and charcoal in watershed soil and reef sediment at Olowalu, Maui, 2022

Fine-sediment elemental chemistry, short-lived cosmogenic radionuclides (Beryllium-7, Cesium-137, and Lead-210), charcoal counts, and total organic carbon contents were quantified to describe urban and wildfire effects and land-based sediment sources and runoff to Olowalu Reef in February 2022.

Census counts of benthic foraminifera, environmental parameters (temperature, salinity, and oxygen concentration), and radiocarbon measurements from cores obtained under and near a whale-fall off western Vancouver Island, British Columbia, Canada

This data release provides census counts of benthic foraminifera (in percent for the total fauna and as raw counts for just the living specimens) as well as environmental parameters (temperature, salinity, and oxygen concentration) at the sampling sites, and radiocarbon measurements from selected push core samples obtained under and near a whale-fall off western Vancouver Island, British Columbia, Canada.

Core descriptions and sedimentologic data from vibracores collected in 2021 from Central Florida Gulf Coast Barrier Islands

In 2021, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) conducted ground penetrating radar (GPR) and sediment sampling surveys on barrier islands located along the central Florida Gulf Coast (CFGC), Pinellas County, Florida (FL). This study investigated the past evolution of the CFGC from field sites at Anclote Keys, Caladesi and Honeymoon Islands, and Fort DeSoto to quantify changes that occurred along these barrier systems prior to the 20th ...

Core descriptions and sedimentologic data from vibracores and sand augers collected in 2021 and 2022 from Fire Island, New York

In 2021 and 2022, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) and the USGS New York Water Science Center (NYWSC), on behalf of SPCMSC, conducted sediment sampling and ground penetrating radar (GPR) surveys at Point O' Woods and Ho-Hum Beach (NYWSC, 2021) and Watch Hill, Long Cove, and Smith Point (SPCMSC, 2022), Fire Island, New York. These data complement previous SPCMSC GPR and sediment sampling surveys conducted at Fire Island in 2016 ...