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.