https://data.amerigeoss.org/dataset/7dfb18d5-1b0a-493d-94f0-f682e6d94eba
type: Dataset
description: This data release documents nine Microsoft Excel tables that contain data for understanding groundwater ages in the Glacial aquifer system. Results for the four sample networks (PAS, principal aquifer study; MSS, modeling support study; FPS, flow path study) are described by three tables each: dissolved gas modeling results, environmental tracer concentrations (tritium, tritiogenic helium-3, sulfur hexafluoride, carbon-14, and radiogenic helium-4), and results for the mean age and age distribution. Tables are labeled by network and data type (as described below) separated by an underscore (_). For example, dissolved gas modeling results from the PAS network is label ‘PAS_NGmodel’. Dissolved gas modeling results (NGmodel) contains detailed information on the calibration of dissolved gas models to dissolved gas concentrations (neon, argon, krypton, xenon, and nitrogen). Calibration was done using methods described by Aeschbach-Hertig and others (1999) with modifications to include nitrogen gas (Weiss 1970). In most cases, a single set of noble gas data (neon, argon, krypton, and xenon) were used to determine recharge conditions (recharge temperature, excess air or entrapped air, fractionation). In cases where noble gas data were not available, multiple analyses of nitrogen and argon (collected sequentially on the same sample date) were used to determine recharge conditions. Environmental tracer results (Tracers) contain detailed information on calculations of environmental tracer data. Dissolved gas models were paired with sulfur hexafluoride and helium isotopes (3He/4He) and helium to determine concentrations of tritiogenic helium-3 (from decay of tritium; Solomon and Cook, 2000) and radiogenic helium-4 (from decay of uranium and thorium in aquifer materials; Solomon, 2000). Multiple tracer concentrations were computed when sites had multiple dissolved gas model results and analyses for sulfur hexafluoride or helium isotopes. Mean age and age distribution results (LP…
issued: 2025-11-22T22:43:01.629048
modified: 20200827
spatial: Location
title: Data Release for Dissolved Gas, Environmental Tracer Concentrations, and Lumped Parameter Modeling Results Used in Determination of Groundwater Mean Age and Age Distributions in the Glacial Aquifer System, Conterminous United States
contact point: Organization
  fn: John E Solder
keyword: amerigeo
keyword: amerigeoss
keyword: ckan
keyword: connecticut
keyword: cycle-3
keyword: dissolved-gas
keyword: geo
keyword: geoss
keyword: glacial-aquifer-system
keyword: groundwater
keyword: groundwater-age
keyword: idaho
keyword: illinois
keyword: indiana
keyword: iowa
keyword: kansas
keyword: lumped-parameter-modeling
keyword: maine
keyword: massachusetts
keyword: michigan
keyword: minnesota
keyword: missouri
keyword: montana
keyword: national
keyword: nawqa
keyword: nebraska
keyword: new-hampshire
keyword: new-jersey
keyword: new-york
keyword: north-america
keyword: north-dakota
keyword: ohio
keyword: pennsylvania
keyword: recharge-temperature
keyword: rhode-island
keyword: south-dakota
keyword: united-states
keyword: usgs-5a3d4f05e4b0d05ee8b8e5cd
keyword: vermont
keyword: washington
keyword: water-quality
keyword: wisconsin
theme: {geospatial}

Digital Data
type: Distribution
description: Landing page for access to the data
format: XML
issued: 2022-08-07T03:32:15.522274
modified: 2025-11-22T22:43:01.607438
access URL: https://doi.org/10.5066/F77S7KT5
media type: application/http

Original Metadata
type: Distribution
description: The metadata original format
format: XML
issued: 2022-08-07T03:32:15.522268
modified: 2025-11-22T22:43:01.606880
access URL: https://data.usgs.gov/datacatalog/metadata/USGS.5a3d4f05e4b0d05ee8b8e5cd.xml
media type: text/xml

US Migrating
type: Agent