AGGREGATE POTENTIAL - GRAVEL PITS

EASTERN CLAY COUNTY, MINNESOTA

Field | Description
Main ID Information | Metadata Updated 2007
Title | Aggregate Resource Potential of Eastern Clay County, Minnesota - Gravel Pits. This layer is part of Minnesota Department of Natural Resources, Minerals Division, Report 306, from 1997.
Filename | Shapefile: gp97apt3
Abstract | This dataset consists of gravel pits located as points, captured from USGS 1:24000 quadrangles or from field work done for this project. This work is authorized by Minnesota Statute 84.94.
Place Keywords | Clay County, Minnesota; eastern 18 townships of county (Barnesville, Cromwell, Eglon, Elkton, Felton, Flowing, Goose Prairie, Hagen, Hawley, Highland Grove, Humboldt, Keene, Parke, Riverton, Skree, Spring Prairie, Tansem, Ulen)
Theme Keywords | Gravel pits
Time Period of Content | 1966-1995
Parent Theme |
Spatial Extent of the Data | Eastern 18 townships of Clay County, Minnesota
Contact Person | Aggregate Resources Mapping Program
Contact Person Organization/Division | Minnesota Department of Natural Resources, Division of Lands and Minerals
Contact Person Position | Geologist or GIS Specialist
Contact Address | 500 Lafayette Road, Box 45
Contact City | St. Paul, MN
Contact Zip Code | 55155-4045
Contact Voice Phone | 651-259-5959
Contact Fax Phone | 651-296-5939
Additional ID Information |
Originator | Department of Natural Resources, Division of Lands and Minerals, Mineral Potential Section.
Purpose | To display the gravel pit locations in Clay County, Minnesota.
Progress | Complete
Currentness Reference | 1966-1995
Maintenance Frequency | None planned
Access Constraints | NA
Use Constraints | NA
Associated Data Sets | shapefiles: agg97py3 - aggregate potential and surficial geology, agg97ln3 - aggregate potential and surficial geology polygon lines, sym97ln3 - surficial geology/aggregate potential lines, gp97bpt3 - MN DOT test pit data, glb97pt3 - MN DOT test pit data - label points Access 97 database: dotpit97.mdb
Data Quality |
Attribute Accuracy |
Logical Consistency |
Completeness |
Horizontal Positional Accuracy | Varies. For pits mapped from USGS topographic maps, positional accuracy is deemed to be within National Map Accuracy Standards for 1:24,000 scale, that is, 40 feet (12.2 meters). For pits mapped by J.D. Lehr, Minnesota Department of Natural Resources, Division of Lands and Minerals, from airphotos and field observations, accuracy is deemed to be within the standards for the source scale of 1:40,000, that is, 67 feet (20 meters).
Vertical Positional Accuracy | NA
Lineage | This shapefile is part of Minnesota Department of Natural Resources, Minerals Divison, Report 306, Aggregate Resource Potential of eastern Clay County, 1997, by JD Lehr and is part of an ongoing statewide program to provide aggregate resource information to the public. For gravel pit features, 1:40,000 1991-1992 NAPP air photos were examined stereographically and recognizable pits were recorded on 1:24,000 scale USGS topographic quadrangle base maps. Some gravel pits that were observed during 1995 were also marked on the USGS maps. All point gravel pits, including those indicated by the USGS on their 1:24,000 topographic quadrangles, were then captured by digitizing in ARC/INFO. Base map for USGS pits is 1:24,000, while for those mapped directly by the Minnesota Department of Natural Resources, Division of Lands and Minerals, Mineral Potential Evaluation Unit, is 1:40,000. The user should recognize that this layer represents a "snapshot in time" of an evolving gravel pit picture in Clay County. Minnesota Department of Natural Resources, Division of Lands and Minerals, gravel pit information is generally dated 1991-1995, and should not be deemed representative of conditions either before or since. For a full discussion of this, contact the agency listed above. Gravel pits derived from USGS topographic map sources often date from the 1960s, and are a different vintage (see attribute QUADYEAR). This data layer presents three classes of gravel pits: a) Points denoted as gravel pit locations on the most current United States Geological Survey (USGS) 1:24,000 topographic quadrangle maps of the Clay County region. These pits are in almost all cases either currently inactive or have become part of larger (areal) gravel pits (as represented in dataset agg97py3). b) Gravel pits recognized on 1991-1992 NAPP photography that were too small to be mapped as area units, and were photointerpreted to be inactive as of that time. c) Active gravel pits, opened since 1991-1992 photo coverage, that were noted during field surveys in the summer of 1995. The description "gravel pit" covers both pits currently being mined as well as areas currently inactive. The distinction between "currently" active and inactive pits is made explicit in the data layer attribute "PITTYPE". This condition is subject to frequent change as pits open or close in response to aggregate supply and market conditions, making such a distinction of limited value. This information should therefore be used with caution. Point pits from USGS topographic quadrangle sources are classed separately (specifying neither active nor inactive), but are included for informational purposes.
Source Scale Denominator | 1:24,000 and 1:40,000
Spatial Reference |
Horizontal Coordinate Scheme | UTM
Ellipsoid | GRS80
Horizontal Datum | NAD83
Horizontal Units | Meters
Distance Resolution | NA
Altitude Datum | NA
Altitude Units | NA
Depth Datum | NA
Depth Units | NA
UTM Zone Number | 15, extended
Raster only |
Cell Width | NA
Cell Height | NA
Spatial Data Organization |
Geographic Reference for Tabular Data | NA
Native Dataset Environment | ArcView 3.1 / Arc/INFO 7.2.1
Vendor Specific Object Type | NA
Tiling Scheme | NA
Spatial Object Type | NA
Transfer Size | 25 kb
Entities -- Attributes |
Entity-Attribute Overview | The dataset includes locational information about the gravel pits in Clay County, Minnesota, as well as the source for the information.
Entity-Attribute Detailed Citation | Complete table below:

Table Name | Field Name | Begin Column | Definition | Valid Values | Descriptions
gp97apt3 shapefile | pittype |  | Number,3,0 | 90=active, 91=inactive, 99=USGS topo quad denoted pit. | Type of pit, given as a numeric code.
| pit_desc |  | Text,20 | Pit-active, Pit-inactive, Pit-USGS quad | Type of pit, described, listed in the same order as above, in pittype.
| source |  | Text,6 | AGGPNT=Minnesota DNR, Division of Lands and Minerals, denoted pit; USGSPT=topo quad denoted pit. | Source of data.
| aggpit |  | Text,1 | Y indicates that the USGS pit falls within a gravel pit mapped as a polygon in the agg97py3 cover; N indicates the pit does not fall within a polygon pit. | An attribute for USGS pits only, indicating if the pits are now part of a larger pit.
| pitnum |  | Number,4,0 | 0=used for all pits located wihtin a larger pit mapped as a polygon; 171-234 used for all the other pits. | Pits that lie within pits mapped as a polygon are not differentiated; a unique number is assigned to all the pits located outside of a pit mapped as a polygon in agg97py3.
| quadyear |  | Number,4,0 | 1966,1973,1981 | Year of source topographic quadrangle for USGS pits.