AGGREGATE POTENTIAL BOUNDARIES BETWEEN

AGGREGATE POTENTIAL MAPPING UNITS

DODGE COUNTY, MINNESOTA

Field | Description
Main ID Information | Metadata Updated 2007
Title | Dodge County Aggregate Evaluation Boundaries between Aggregate Potential Mapping Units
Filename | Agg02ln3 (ArcView Shapefile)
Abstract | This dataset consists of information about the types of geologic contacts, or boundaries, between the mapping unit polygons of the aggregate potential layer. The seven types of contacts or boundaries are county border, geologic contact inferred, geologic contact well defined, channel scarp inferred, channel scarp well defined, glacial margin inferred, channel margin well defined.
Place Keywords | Dodge County, Minnesota
Theme Keywords | Geological contacts, channel scarps, glacial margin
Time Period of Content | Fall 2001 and Spring 2002
Parent Theme | NA (Agp02py3)
Spatial Extent of the Data | Dodge County, Minnesota
Contact Person | Aggregate Resources Mapping Program
Contact Person Organization/Division | 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
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 differentiate the types of geological contacts so that various line symbols (e.g., solid lines, hatched lines, or dashed lines) can be used to show the contacts between polygons on a map.
Progress | Complete
Currentness Reference | All data was gathered in summer and fall of 2001 and compiled in the fall of 2001 through the spring of 2002.
Maintenance Frequency | None planned
Access Constraints | NA
Use Constraints | NA
Associated Data Sets | County Aggregate Mapping Program datasets for Dodge County, including data on sand and gravel potential, crushed stone potential, field observations, rock piles, and test pit quality.
Data Quality |
Attribute Accuracy | The lines delineating the sand and gravel resources and surficial geology were digitized on screen with DOQs (1:12000 USGS Digital Orthophotoquadrangles) and DRGs (1:24000 USGS scanned topographic maps digital raster graphics) as the backdrops. The lines delineating the crushed stone resources were based on a model to define a depth to bedrock surface (see the Lineage section below for additional information).
Logical Consistency | Overshoots, undershoots, etc. were fixed by a variety of techniques, thus the lines have been checked and completed.
Completeness | The sand and gravel resource units were delineated by aerial photograph (at a scale of 1:40,000) interpretation and digitized onscreen, using ARCVIEW with 1:12000 USGS DOQs and 1:24000 USGS DRGs as the spatially registered backdrops.
Horizontal Positional Accuracy | 1:50000
Vertical Positional Accuracy | Not applicable
Lineage | For sand and gravel: Color infrared and black-and-white aerial photographs were used to delineate geological landforms and aggregate resources. Stereoscopic pairs of color infrared aerial photographs (NAPP, 9"x9" at 1:40,000 scale, April 1991 and 1992) were used along with reconnaissance-level, high-altitude, black-and-white photographs (1:80,000 scale). Aerial photographs (DOQs) were also available digitally and used within ARCVIEW (1:12,000 scale). Aerial photographic interpretation was completed with a glacial mapping technique known as the landsystems approach. This technique relies on the principle that depositional glacial landforms are composed of a predictable range of sediments, some consisting of sorted sand and gravel and others consisting of silts, clays, or unsorted materials. In addition to the landsystems approach, several other general characteristics helped determine the nature of the material, such as tonal contrasts, texture, context, shape, size, trend, association, and patterns. These characteristics can help determine the properties of the surface material (e.g., certain vegetation grows on well drained soils such as sand and gravel, which on an aerial photograph has a distinctive texture, tone, pattern, etc.). The landform recognition approach (part of the landsystems approach) was also used when interpreting the topography within Dodge County; glacial landforms have distinct and unique shapes and patterns that can be observed in their topographic expression. Topographic maps (USGS 1:24,000), digital elevation models, and shaded relief maps were all used to help delineate these sand and gravel bearing features. The topographic expression of a feature can also be observed by looking at the distribution of lakes and wetlands. For example, a string of lakes and/or wetlands may be the signature of a glacial outwash channel or collapsed channel, which may host sand or gravel deposits. Several aggregate bearing features were located using this technique (outwash channels, collapsed channels, glaciofluvial fans, eskers, and terraces).
Source Scale Denominator | 1:50000
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 | .
Native Dataset Environment | ArcView 3.1 / ArcInfo 8.0.2
Vendor Specific Object Type | NA
Tiling Scheme | NA
Spatial Object Type | Vector
Transfer Size |
Entities -- Attributes |
Entity-Attribute Overview | The lines delineate the polygon mapping units found in the aggregate potential layer. Note: some of these lines, specifically the channel scarps and glacial margin, are also found in the sgeoxln3 shapefile, to enable the user to portray these special features as a continuous line symbol.
Entity-Attribute Detailed Citation | ArcView specific fields include shape (i.e., feature type - polyline), fnode_ (id of beginning node of line), tnode_ (id of ending node of line), lpoly_ (id of polygon to the left of the line - 0" if a line feature, not a line defining a polygon), rpoly_ (id of polygon to the right of the line - 0" if a line feature, not a line defining a polygon), length (length of the line segment), agp02ne3_ (unique id for line, assigned by Arc/INFO software), agp02ne3_i (an id usually assigned during theme creation). The aggregate potential line attributes are described in the table below.

Table Name | Field Name | Begin Column | Definition | Valid Values | Descriptions
Agg02ln3.shp | Uniqln_id |  | Number,3,0 | 1 | Dodge County Boundary
|  |  |  | 261 | Geological contact - well defined
|  |  |  | 262 | Geological contact inferred
|  |  |  | 265 | Channel Scarp - well defined
|  |  |  | 266 | Channel Scarp inferred
|  |  |  | 270 | Glacial Margin well defined
|  |  |  | 271 | Glacial Margin - inferred
| Agplntype |  | Text, 33 | County Boundary | Descriptions of unique Identifiers
|  |  |  | Geological Contact (Well Defined) | Geological contact - well defined
|  |  |  | Geological Contact (Inferred) | Geological contact - inferred
|  |  |  | Channel Scarp (Well Defined) | Channel Scarp - well defined
|  |  |  | Channel Scarp (Inferred) | Channel Scarp - inferred
|  |  |  | Glacial Margin (Well Defined) | Glacial Margin well defined
|  |  |  | Glacial Margin (Inferred) | Glacial Margin - inferred