Field |
Description |
Main ID Information |
Metadata Updated 2007 |
Title |
Blue Earth County Aggregate Evaluation - Features (lines) |
Filename |
Sgsymln3 (ArcView Shapefile) |
Abstract |
This dataset consists of information about the types of landforms and features that are represented by an line (arc). These landforms consist of crevasse fills, eskers, and moraine ridges. |
Place Keywords |
Blue Earth County, Minnesota |
Theme Keywords |
Landforms, Features |
Time Period of Content |
Summer 1998 |
Parent Theme |
NA (SG99XPY3) |
Spatial Extent of the Data |
Blue Earth County, Minnesota |
Contact Person |
Aggregate Resources Mapping Program |
Contact Person Organization/Division |
Department of Natural Resources, Division of 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 Minerals, Mineral Potential Section |
Purpose |
To display linear geologic landforms and features that were too small to be mapped as polygons. |
Progress |
Complete |
Currentness Reference |
1998-1999 |
Maintenance Frequency |
Non planned |
Access Constraints |
NA |
Use Constraints |
NA |
Associated Data Sets |
Surficial Geology (sg99xpy3.shp and sg99xln3.shp) |
Data Quality |
|
Attribute Accuracy |
These lines were digitized off 1:24,000 topographic maps. |
Logical Consistency |
NA |
Completeness |
The units were delineated by aerial photograph interpretation (1:40,000) and transferred onto 1:24,000 topographic maps. |
Horizontal Positional Accuracy |
1:50000 |
Vertical Positional Accuracy |
NA |
Lineage |
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; Figure 2). 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 Blue Earth 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, deltas, kames, 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 |
Raster only |
|
Cell Width |
NA |
Cell Height |
NA |
Spatial Data Organization |
|
Geographic Reference for Tabular Data |
The lines represent geologic landforms that are too small to be mapped as polygons. |
Native Dataset Environment |
ArcView 3.1 / ArcInfo7.2.1 |
Vendor Specific Object Type |
NA |
Tiling Scheme |
NA |
Spatial Object Type |
Vector |
Transfer Size |
87.9 kb |
Entities -- Attributes |
|
Entity-Attribute Overview |
The lines represent geologic landforms that are too small to be mapped as polygons. |
Entity-Attribute Detailed Citation |
See table below: 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), filename_ (unique id for line, assigned by software), filename_i or filename_id if filename is less than 8 characters (an id usually assigned during theme creation). |
Table Name |
Field Name |
Begin Column |
Definition |
Valid Values |
Descriptions |
Sgsymln3.shp |
Uniqln_id |
|
Number,3,0 |
250 |
Crevasse Fill - distinct |
|
|
|
|
251 |
Crevasse Fill - less distinct |
|
|
|
|
255 |
Esker - well defined |
|
|
|
|
260 |
Moraine - distinct |
|
|
|
|
261 |
Moraine - less distinct |
|
Sgeolntype |
|
Text, 30 |
Crevasse Fill - distinct |
Landform description - Crevasse Fill - distinct |
|
|
|
|
Crevasse Fill - less distinct |
Crevasse Fill - less distinct |
|
|
|
|
Esker - well defined |
Esker - well defined |
|
|
|
|
Moraine - distinct |
Moraine ridge - distinct |
|
|
|
|
Moraine - less distinct |
Moraine ridge - less distinct |