Dataset Identification:
Resource Abstract:
- description: The United States Geological Survey (USGS), in collaboration with other state and federal agencies, industry,
and academia, is conducting a National Geochemical Survey (NGS) to produce a database of geochemical information for the United
States based primarily on stream sediments, analyzed using a single set of methods. This data set will comprise a national-scale
geochemical coverage of the US, and will enable construction of geochemical maps, refine estimates of baseline chemical element
concentrations in the sampled media, and provide context for a wide variety of geological and environmental studies. The goal
of the NGS is to analyze at least one stream-sediment sample within every 289 km2 area across the US, using a consistent set
of analytical methods, substituting soil samples where necessary. The survey incorporates geochemical data from a variety
of sources, including existing analyses in USGS databases, reanalyses of samples in USGS archives, and analyses of recently
collected samples. Currently, the NGS data covers ~71% of the land area of the US, and includes samples from all 50 states.
The Iowa Geological Survey (IGS) of the Iowa Department of Natural Resources (IDNR) entered into an agreement with the USGS
in September of 2002 whereby the IGS would design a database for field parameters and collect two soil sample sets. One set
for the USGS to process and analyze, and one set to reposit. Field parameters included ambient site conditions, GPS location,
elevation, landscape position, vegetation type, NRCS soil type, sample depth, and soil horizon, texture, color and moisture.
Digital photographs were taken of the site and samples at each location. The samples were sieved to -100 mesh, then analyzed
for 40 elements using inductively coupled plasma-atomic emission spectrometry/acid dissolution (ICP40), and 6 elements using
atomic absorption spectrometry (AA). Arsenic (As) and gold (Au) were analyzed for using both methods. Analyses were performed
by the USGS or an approved laboratory, using standard methods and an U.S.E.P.A. approved quality assurance/quality control
plan. To maximize statistical reliability, sample collection in Iowa was based on a 17 km x 17 km grid, displayed on USGS
1:250,000 quad maps. Each grid or cell was identified by quad name and cell column and row position, and divided into four
72 km2 quadrants, and one was selected at random for sampling. The IGS selected specific sampling sites within the selected
quadrants. To separate leached horizons from those accumulating CO3, one shallow (0-8 inches) and one deep (12-24 inches)
sample were collected from 463 regular and 72 analysis of variance (AOV) sites from May through August of 2003 and shipped
to the USGS in August. Randomly selected AOV sites were sampled to provide a data set for statistical analysis to test the
adequacy of the samples to measure differences of sediment chemistry between cells, within cells, within sites, and between
chemical analyses. "AOV1" was collected within the designated quadrant of the cell, then one of the three other
quadrants of the cell were selected at random for "AOV2" and "AOV3" which were collected about 10 feet
apart, preferably within the same soil type. The field data were described on data collection sheets and later transferred
to the IGS network through an entry routine on a daily to weekly basis. The DBASE entry routine and database were developed
and maintained by IGS personnel, then after the analyses were performed, the data were joined with the soil sample analyses
by USGS personnel. The joined database can be accessed at the IGS website at http://www.igsb.uiowa.edu, and for a detailed
description of the NGS, visit the USGS website at http://tin.er.usgs.gov/geochem/doc/home.htm; abstract: The United States
Geological Survey (USGS), in collaboration with other state and federal agencies, industry, and academia, is conducting a
National Geochemical Survey (NGS) to produce a database of geochemical information for the United States based primarily on
stream sediments, analyzed using a single set of methods. This data set will comprise a national-scale geochemical coverage
of the US, and will enable construction of geochemical maps, refine estimates of baseline chemical element concentrations
in the sampled media, and provide context for a wide variety of geological and environmental studies. The goal of the NGS
is to analyze at least one stream-sediment sample within every 289 km2 area across the US, using a consistent set of analytical
methods, substituting soil samples where necessary. The survey incorporates geochemical data from a variety of sources, including
existing analyses in USGS databases, reanalyses of samples in USGS archives, and analyses of recently collected samples. Currently,
the NGS data covers ~71% of the land area of the US, and includes samples from all 50 states. The Iowa Geological Survey (IGS)
of the Iowa Department of Natural Resources (IDNR) entered into an agreement with the USGS in September of 2002 whereby the
IGS would design a database for field parameters and collect two soil sample sets. One set for the USGS to process and analyze,
and one set to reposit. Field parameters included ambient site conditions, GPS location, elevation, landscape position, vegetation
type, NRCS soil type, sample depth, and soil horizon, texture, color and moisture. Digital photographs were taken of the site
and samples at each location. The samples were sieved to -100 mesh, then analyzed for 40 elements using inductively coupled
plasma-atomic emission spectrometry/acid dissolution (ICP40), and 6 elements using atomic absorption spectrometry (AA). Arsenic
(As) and gold (Au) were analyzed for using both methods. Analyses were performed by the USGS or an approved laboratory, using
standard methods and an U.S.E.P.A. approved quality assurance/quality control plan. To maximize statistical reliability, sample
collection in Iowa was based on a 17 km x 17 km grid, displayed on USGS 1:250,000 quad maps. Each grid or cell was identified
by quad name and cell column and row position, and divided into four 72 km2 quadrants, and one was selected at random for
sampling. The IGS selected specific sampling sites within the selected quadrants. To separate leached horizons from those
accumulating CO3, one shallow (0-8 inches) and one deep (12-24 inches) sample were collected from 463 regular and 72 analysis
of variance (AOV) sites from May through August of 2003 and shipped to the USGS in August. Randomly selected AOV sites were
sampled to provide a data set for statistical analysis to test the adequacy of the samples to measure differences of sediment
chemistry between cells, within cells, within sites, and between chemical analyses. "AOV1" was collected within
the designated quadrant of the cell, then one of the three other quadrants of the cell were selected at random for "AOV2"
and "AOV3" which were collected about 10 feet apart, preferably within the same soil type. The field data were described
on data collection sheets and later transferred to the IGS network through an entry routine on a daily to weekly basis. The
DBASE entry routine and database were developed and maintained by IGS personnel, then after the analyses were performed, the
data were joined with the soil sample analyses by USGS personnel. The joined database can be accessed at the IGS website at
http://www.igsb.uiowa.edu, and for a detailed description of the NGS, visit the USGS website at http://tin.er.usgs.gov/geochem/doc/home.htm
Citation
- Title National Geochemical Survey Locations and Results for Iowa.
-
- creation Date
2013-07-19T16:00:27.646351
Resource language:
Processing environment:
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Digital Transfer Options
-
- Linkage for online resource
-
- name Dublin Core references URL
- URL: http://<http://tin.er.usgs.gov/geochem/>
- protocol WWW:LINK-1.0-http--link
- link function information
- Description URL provided in Dublin Core references element.
Metadata data stamp:
2018-08-06T21:11:05Z
Resource Maintenance Information
- maintenance or update frequency:
- notes: This metadata record was generated by an xslt transformation from a dc metadata record; Transform by Stephen M. Richard, based
on a transform by Damian Ulbricht. Run on 2018-08-06T21:11:05Z
Metadata contact
-
pointOfContact
- organisation Name
CINERGI Metadata catalog
-
- Contact information
-
-
- Address
-
- electronic Mail Address cinergi@sdsc.edu
Metadata language
eng
Metadata character set encoding:
utf8
Metadata standard for this record:
ISO 19139 Geographic Information - Metadata - Implementation Specification
standard version:
2007
Metadata record identifier:
urn:dciso:metadataabout:5013a350-eaa9-46ab-991d-e05e8a64146f
Metadata record format is ISO19139 XML (MD_Metadata)