Great Basin Groundwater Sodium Concentration Map

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Zehner, R.E.
Originator: Coolbaugh, M.F.
Originator: Shevenell, Lisa
Publication_Date: 20120831
Title: Great Basin Groundwater Sodium Concentration Map
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: University of Nevada, Reno
Publisher: Nevada Bureau of Mines and Geology
Other_Citation_Details:
Zehner, R.E., Coolbaugh, M.F., and Shevenell, Lisa, 2006, Regional groundwater geochemical trends in the Great Basin: Implications for Geothermal Exploration, GRC Transactions 2006
Online_Linkage:
\\palido.unr.edu\geothermal\_projects\metadata_updates\_auth\tdozet\04_Geochemical\RicksCationAnionGrids2012\gbsodium
Description:
Abstract:
Maps of Great Basin groundwater geochemistry show distinctive regional spatial patterns. Factors affecting the concentrations of dissolved constituents include bedrock lithology, location within structural zones, geothermal systems, and surficial playa deposits and salt lakes. In this study, a large geochemical database of ~51,577 Great Basin groundwater samples from springs and wells was compiled from multiple sources. These data were uploaded into a geographic information system (GIS) and used to produce concentration maps for As, B, Ba, Ca, Cl, F, Fe, HCO3, K, Li, Mg, Mn, Na, SiO2, and SO4. These maps were then examined to identify geologic factors that might have influenced their concentration, including the presence of geothermal systems.
Purpose: Geothermal exploration
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date:
REQUIRED: The year (and optionally month, or month and day) for which the data set corresponds to the ground.
Currentness_Reference:
REQUIRED: The basis on which the time period of content information is determined.
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -122.917337
East_Bounding_Coordinate: -110.435490
North_Bounding_Coordinate: 44.034041
South_Bounding_Coordinate: 34.515813
Keywords:
Theme:
Theme_Keyword_Thesaurus:
REQUIRED: Reference to a formally registered thesaurus or a similar authoritative source of theme keywords.
Theme_Keyword: geochemistry
Theme_Keyword: groundwater
Theme_Keyword: hot spring
Theme_Keyword: sodium
Place:
Place_Keyword: USA
Place_Keyword: Western United States
Place_Keyword: Great Basin
Place_Keyword: Nevada
Place_Keyword: California
Place_Keyword: Utah
Place_Keyword: Idaho
Place_Keyword: Arizona
Place_Keyword: Oregon
Place_Keyword: Wyoming
Access_Constraints:
Although these data have been processed successfully on the computer system at the Nevada Bureau of Mines and Geology, no warranty expressed or implied is made regarding the accuracy or utility of the data on any system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that these data be directly acquired from the Nevada Bureau of Mines and Geology. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with the data. The Nevada Bureau of Mines and Geology shall not be held liable for improper use of the data described and/or contained herein. By using this data you hereby agree to these conditions.
Use_Constraints:
Reference and acknowledge the Nevada Bureau of Mines and Geology or specific author in products derived from this map. Do not reproduce for commercial purposes. This data is not surveyed data.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Nevada Bureau of Mines and Geology
Contact_Person: web/GIS/database person
Contact_Position: web/GIS/database
Contact_Address:
Address_Type: mailing and physical address
Address: University of Nevada, Reno MS178
City: Reno
State_or_Province: NV
Postal_Code: 89557-0178
Country: USA
Contact_Voice_Telephone: 775-784-6691
Contact_Electronic_Mail_Address: nbmg@unr.edu
Hours_of_Service: 8:00 a.m. - 3:00 p.m. (PST)
Contact_Instructions: web/GIS/database person
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.1850
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Unknown. Data is derived from several sources (NWIS, Geo-Heat Center, NBMG Geothermal Database) with unknown sample location and attribute accuracy.
Logical_Consistency_Report: Unknown
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: unknown
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report: unknown
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Zehner, R.E.
Originator: Coolbaugh, M.F.
Originator: Shevenell, Lisa
Publication_Date: 20060530
Title:
Regional Groundwater Geochemical Trends in the Great Basin, Implications for Geothermal Exploration
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: University of Nevada, Reno
Publisher: Nevada Bureau of Mines and Geology
Process_Step:
Process_Description:
The data set was constructed using groundwater geochemical data (springs and wells) from the Great Basin Groundwater Geochemical Database (<http://www.unr.edu/geothermal/GeochemDB.htm>) Spring and well samples within a 100 km radius of the Great Basin were used so that outside values would form a continuous concentration surface right up to the Great Basin boundary. Not all samples were analyzed for all constituents; few of the samples were analyzed for all 14 constituents that were examined. The data were first screened to remove surface water samples. Next, some of the data had analytical flags that were treated as below:
FLAG DATA "N.D." or "Not detected" Removed from dataset "<" or "L.T." (less than) Value reset to one half lower detection limit ">" or "G.T." (greater than) Value set to 1.5 times detection limit EST or "Estimated" Included in dataset All other flags Removed from dataset
Next, a histogram analysis was performed that identified that all constituents followed an approximate log-normal distribution. Consequently, the [natural] log of concentration of the 14 cations/anions was calculated. Some sites had multiple sampling; the sample values of each constituent at each site were then averaged: for the database in its one-to-many format, sample data was averaged for each location of the site table.
The following table shows the number of samples, sites, and the amount of flagged data (kept in the dataset) for each constituent:
CONSTITUENT SAMPLES SITES FLAGGED DATA As 8,234 3,285 931 B 13,554 2,661 338 Ba 4,042 6,114 262 Ca 23,112 10,990 16 Cl 29,169 11,822 71 F 19,615 9,126 1,218 Fe 13,633 6,439 4,821 HCO3 6,254 3,653 3 K 20,081 9,544 19 Li 4,416 2,907 258 Mg 22,507 10,689 131 Mn 11,339 5,396 5,731 Na 22,013 10,057 11 SiO2 20,225 9,858 22 SO4 25,031 11,181 214 TOTAL DATASET 51,576

The log-normalized point data were then interpolated over the Great Basin using an inverse distance weighting (IDW) method (neighbors = 12, power = 2) to generate a set of concentration maps. Maps were produced for As, B, Ba, Ca, Cl, F, Fe, HCO3, K, Li, Na, Mn, SO4, and SiO2. The sample density of some cations (As, Ba, Fe, Li, Mn) was limited over portions of the Great Basin; large areas greater than 50 km from the nearest sample site were not considered in the analysis and appear as blank areas on the maps. The resulting grid maps were then clipped to the Great Basin boundaries as defined by <http://www.unr.edu/geothermal/MetadataPages/gboutline.htm>.
The IDW interpolation method estimates values between points using a 'nearest neighbors' approach, which does not take into account hydrologic factors such as basin boundaries, faults, or low-permeability rock units. Since deep-seated geothermal systems operate primarily below the region of near-surface groundwater flow, this approach is probably warranted for the analysis of regional groundwater trends. The smoothness of the concentration gradients on most of the maps attests to the relative uniformity of sample concentrations at the regional scale.
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 2071
Column_Count: 2001
Vertical_Count: 1
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 11
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -117.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 500.000000
Ordinate_Resolution: 500.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6378206.400000
Denominator_of_Flattening_Ratio: 294.978698
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: AREA
Attribute:
Attribute_Label: PERIMETER
Attribute:
Attribute_Label: FEDLANP020
Attribute:
Attribute_Label: FEATURE1
Attribute:
Attribute_Label: FEATURE2
Attribute:
Attribute_Label: FEATURE3
Attribute:
Attribute_Label: AGBUR
Attribute:
Attribute_Label: URL
Attribute:
Attribute_Label: NAME1
Attribute:
Attribute_Label: NAME2
Attribute:
Attribute_Label: NAME3
Attribute:
Attribute_Label: STATE
Attribute:
Attribute_Label: STATE_FIPS
Overview_Description:
Entity_and_Attribute_Overview:
The grid units are the natural log of concentration. They are in ESRI real number format with a cell size = 500 m. The data set was constructed using groundwater geochemical data (springs and wells) from the Great Basin Groundwater Geochemical Database (<http://www.unr.edu/geothermal/GeochemDB.htm>). This database comes from three primary sources: (1) the National Water Information System ("NWIS", USGS, 2005), which includes cold temperature springs and wells along with the former GEOTHERM database, (2) the Nevada Bureau of Mines and Geology's geothermal database (http: HTTP://www.nbmg.unr.edu/geothermal/gthome.htm), and (3) the Geo-Heat Center's Western Geothermal Database (Reed et al., 1983; Boyd, 2002).
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Nevada Bureau of Mines and Geology
Contact_Person: web/GIS/database person
Contact_Position: web/GIS/database
Contact_Address:
Address_Type: mailing and physical address
Address: University of Nevada, Reno MS178
City: Reno
State_or_Province: NV
Postal_Code: 89557-0178
Country: USA
Contact_Voice_Telephone: 775-784-6691
Contact_Electronic_Mail_Address: nbmg@unr.edu
Hours_of_Service: 8:00 a.m. - 3:00 p.m. (PST)
Contact_Instructions: web/GIS/database person
Resource_Description: Downloadable Data
Distribution_Liability:
Requestor hereby releases the Nevada Bureau of Mines and Geology, the University of Nevada, Reno, and their agents, consultants, contractors or employees from any and all claims, action, or causes of action for damages including, but not limited to any costs of recovering, reprogramming or reproducing any programs or data stored in or used with the GIS data, damage to property, damages for personal injury or for any lost profits, lost savings, or other special, incidental or consequential damages arising out of the use of or inability to use the GIS data, even if said parties have been advised of the possibility of such damage. Requestor agrees to indemnify and hold harmless the Nevada Bureau of Mines and Geology, the University of Nevada, Reno, and their agents, consultants, contractors and employees from any and all liability claims or damages to any person arising from or connected with the use of this GIS data.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
File_Decompression_Technique: Zip file
Transfer_Size: 16.250
Metadata_Reference_Information:
Metadata_Date: 20100706
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Nevada Bureau of Mines and Geology
Contact_Person: web/GIS/database person
Contact_Position: web/GIS/database
Contact_Address:
Address_Type: mailing and physical address
Address: University of Nevada, Reno, MS 178
City: Reno
State_or_Province: NV
Postal_Code: 89557-0178
Country: USA
Contact_Voice_Telephone: 775-784-6691
Contact_Electronic_Mail_Address: nbmg@unr.edu
Hours_of_Service: 8:00 a.m. - 3:00 p.m. (PST)
Contact_Instructions: web/GIS/database person
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile
Generated by mp version 2.9.14 on Fri Sep 14 13:20:03 2012