SURFICIAL GEOLOGY - BOUNDARY
LINES
Field |
Description |
Main ID Information |
Metadata Updated 2007 |
Title |
Nicollet County Aggregate Evaluation - Surficial Geology |
Filename |
Sg00xln3 (ArcView Shapefile) |
Abstract |
This dataset consists of information about the types of boundary lines found within the surficial geology layer. The six types of lines between mapping units are: the County border, Geologic Contact (inferred), Geologic Contact (Well Defined), Channel Scarp (Inferred), Channel Scarp (Well Defined), and North Mankato. |
Place Keywords |
Nicollet County, Minnesota |
Theme Keywords |
Boundary Lines, Geological Contacts |
Time Period of Content |
Summer and Fall 1999 |
Parent Theme |
NA (SG00XPY3) |
Spatial Extent of the Data |
Nicollet County, Minnesota |
Contact Person |
Aggregate Resource Mapping
Program (Geologist or GIS Specialist) St. Paul, MN 55155-4045 |
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 (solid, hatched, or dashed) can be used to show these contacts on a map. |
Progress |
Complete |
Currentness Reference |
1999-2000 |
Maintenance Frequency |
None planned |
Access Constraints |
NA |
Use Constraints |
NA |
Associated Data Sets |
Surficial Geology (sg00xpy3.shp and sgsymln3) |
Data Quality |
|
Attribute Accuracy |
These lines were digitized on screen with DOQ's and DRG's (topographic maps) as the backdrops. |
Logical Consistency |
Overshoots, undershoots, etc. were fixed by a variety of techniques, thus the lines have been checked and completed. |
Completeness |
The units were delineated by aerial photograph interpretation (1:40,000), and digitized on screen using ARCVIEW; with DOQ's and DRG's (topographic maps) as the backdrops. |
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). 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 Nicollet 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, galaciofluvial 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 |
Raster only |
|
Cell Width |
NA |
Cell Height |
NA |
Spatial Data Organization |
|
Geographic Reference for Tabular Data |
The units that the lines delineate are referenced as geological features. |
Native Dataset Environment |
ArcView 3.1 / ArcInfo 8.0.2 |
Vendor Specific Object Type |
NA |
Tiling Scheme |
NA |
Spatial Object Type |
Vector |
Transfer Size |
2669 kb |
Entities -- Attributes |
|
Entity-Attribute Overview |
Arcs that delineate polygon features for the surficial geology layer. |
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 |
Sg00xln3.shp |
Uniqln_id |
|
Number,3,0 |
1 |
Nicollet County Boundary |
|
|
|
|
261 and 761 |
Geological contact - well defined |
|
|
|
|
262 and 762 |
Geological contact - inferred |
|
|
|
|
265 and 765 |
Channel Scarp - well defined |
|
|
|
|
266 and 766 |
Channel Scarp - inferred |
|
|
|
|
269 |
North Mankato (City Boundary) |
|
Sgeolntype |
|
Text, 30 |
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 |
|
|
|
|
North Mankato (City Boundary) |
City boundary of North Mankato |