AGGREGATE POTENTIAL – SAND AND
GRAVEL MAPPING UNITS
DODGE COUNTY, MINNESOTA
Field |
Description |
Main ID Information |
Metadata Updated 2007 |
Title |
Dodge County Aggregate
Resource Evaluation |
Filename |
Agg02py3 (ArcView
Shapefile) |
Abstract |
This dataset consists
of information about the geology, geological characteristics, and sand and
gravel potential of 69 map units.
Five fields (attributes) relate to the surficial geology of the map
unit. Eleven fields (attributes)
relate to the sand and gravel characteristics, including probability,
quality, texture, overburden thickness, and deposit size, of the map
unit. These characteristics were used
to calculate the aggregate potential of the map unit for sand and gravel. |
Place Keywords |
Dodge County, Minnesota |
Theme Keywords |
Surficial Geology,
Geological Characteristics, Aggregate Potential, Sand, Gravel |
Time Period of
Content |
Fall 2001 – Spring 2002 |
Parent Theme |
|
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 summarize the
geological characteristics, surficial geology, and aggregate potential (sand,
gravel) of the different units. To
help categorize the geological characteristics and incorporate them into a
model to help determine the aggregate potential of the deposit. |
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. |
Data Quality |
|
Attribute Accuracy |
|
Logical Consistency |
NA |
Completeness |
The sand and gravel and
surficial geology units were delineated by the interpretation of aerial
photographs at a 1:40000 scale. These
interpretations were plotted on 1:24000 USGS topographic maps. These delineations and unit descriptions
were field checked and revised. The
final coverage was digitized onscreen using Arcview with USGS DOQs (at a
scale of 1:12000) and USGS DRGs (at a scale of 1:24000) as the spatially
registered backdrops. This was a
reconnaissance-scale survey and was mapped at 1:50000. |
Horizontal
Positional Accuracy |
1:50,000 for sand and
gravel. |
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 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 |
1:50,000 |
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 |
|
Native Dataset
Environment |
ArcView 3.1/ArcInfo
8.0.2 |
Vendor Specific
Object Type |
NA |
Tiling Scheme |
County |
Spatial Object Type |
Vector-polygon |
Transfer Size |
2080 kb |
Entities --
Attributes |
|
Entity-Attribute
Overview |
The polygons were delineated to represent geological features, geological characteristics, and aggregate potential for sand and gravel. |
Entity-Attribute
Detailed Citation |
ArcView specific fields
include shape (i.e., feature type = polygon), area (given in square meters),
perimeter (given in meters), Agg02ne3_ (counter field - assigned by the software),
and Agg02ne3_id (an id usually assigned during theme creation). The aggregate potential attributes for the polygons are described in the table below. |
Table Name |
Field Name |
Begin Column |
Definition |
Valid Values |
Descriptions |
Agg02py3.dbf |
Sg_mapu |
|
Number,4,0 |
Ex: 101-240. |
Unique identifier for
mapping units |
|
Surfdesc |
|
Text, 60 |
Ex: Glaciofluvial Outwash, Outwash Modified
Till. |
A short, summarized description
of the surficial geologic mapping units. |
|
Sgeo_age |
|
Text, 30 |
Ex: Holocene,
Precambrian, Quaternary, etc. |
Describes the age of
the material encountered at the surface. |
|
Surfgeo_pl3 |
|
Text, 50 |
Ex: Alluvial Fan Sediments,
Alluvial Terrace Sediments, Glaciofluvial Fan Sediments, etc. |
Describes the surficial
geologic unit. It may be a bedrock
material, a glacial sediment, or a modern Holocene sediment |
|
Sgeo_proc |
|
Text, 30 |
Alluvial |
The geological process
that deposited these features. Alluvial processes are modern stream
processes. |
|
|
|
|
Alluvial over
Glaciofluvial |
Modern stream processes
overlying glaciofluvial (glacial stream) processes |
|
|
|
|
Bedrock |
Ordovician age
limestones, shales, and sandstones that were deposited by an ancient sea
millions of years ago. |
|
|
|
|
Colluvium |
Material that was
deposited as slope wash or slump along steep banks. |
|
|
|
|
Eolian |
Material that was deposited
by wind. |
|
|
|
|
Eeolian over
Glaciofluvial |
Material that was
deposited by wind overlying glaciofluvial (glacial stream) processes |
|
|
|
|
Eroded Glaciofluvial |
Glacial sediments that were
originally sorted and deposited by meltwater and was has since been subject
to erosion |
|
|
|
|
Erosional Glacial |
Unsorted glacial
material that was subject to erosion. |
|
|
|
|
Glacial |
Unsorted glacial
material deposited in place. |
|
|
|
|
Glaciofluvial |
Glacial sediments that
have been sorted by meltwater. |
|
|
|
|
Laucustrrine |
Sediments deposited at
the bottom of an ancient glacial lake. |
|
Sgeo_feat |
|
Text, 35 |
Ex: Alluvial Fan, Alluvial
Terrace, Bedrock Outcrop, Beach, Kame, Esker, Flood Plain, etc... |
The type of geological
feature encountered at the surface (surficial geology). Surficial Geology is defined as the geologic
units encountered within the top 5 to 10 feet of the surface. |
|
Sgeo_mat |
|
Text, 35 |
Ex: Des Moines Till,
Granite, Sand, Sand and Gravel, Silt and Clay, etc… |
The dominant type of
material encountered in the surficial geologic unit. |
|
Sg_prob |
|
Text, 20 |
Very High, High,
Moderately High, Moderate, Moderately Low, Low, Very Low. |
The relative degree of
certainty that sand and gravel exists within a unit. Based on air photo interpretations, field
observations, CWI, drilling, presence of gravel pits and quarries, etc. Each unit is relative to the other units
and range from very high to very low. |
|
Sg_depsize |
|
Text, 20 |
Very Large |
Size of the sand and
gravel deposit (areal extent). Ex:
number of acres. A very large deposit
would be considered > 50 acres. |
|
|
|
|
Large |
40-50 acres |
|
|
|
|
Moderately Large |
30-40 acres |
|
|
|
|
Moderate |
20-30 acres |
|
|
|
|
Moderately Small |
10-20 acres |
|
|
|
|
Small |
5-10 acres |
|
|
|
|
Very Small |
< 10 acres |
|
Sg_thick |
|
Text, 10 |
Ex: 0-10, <10,
>10, 20-50, >50 |
The assumed range of
thickness of the sand and gravel deposit (in feet). |
|
Sg_ovrbrdn |
|
Text, 10 |
Ex:
0-10, 0-3,<5, >20, 10-20, 20-50 |
The assumed range of
overburden thickness of a sand and gravel deposit (in feet). |
|
Sg_texture |
|
Text, 20 |
Very Good, Good,
Moderately Good, Moderate, Moderately Poor, Poor, Very Poor. |
A relative scale of the
textural quality of the sand and gravel resource (sieve analysis). The coarser the material the higher the
rating. Fine sand material would have
a poorer rating. See MN/DOT Pit
sheets for more detail. |
|
Sg_quality |
|
Text, 20 |
Very Good, Good, Moderately
Good, Moderate, Moderately Poor, Poor, Very Poor. |
A relative scale of the
quality of the sand and gravel (soundness, durability, and mineral
makeup). Determined from MN/DOT pit
sheets. |
|
Sg_pot_pl1 |
|
Text, 15 |
Limited, Sand and Gravel. |
Sand
and Gravel Potential that is depicted on plate 1 (Significant Aggregate
Resources). Sand and Gravel refers to
those units that have a high to moderate potential of containing significant
sand and gravel deposits.
Desirability is determined by the sand and gravel potential attributes
(Sg_xxxxx, as described above). |
|
Sg_pot_pl2 |
|
Text, 15 |
High, Moderate, Low,
Limited. |
Sand and Gravel
Potential that is depicted on plate 2 (Aggregate Resources). High, Moderate, and Low refer to the
relative potential of the Sand and Gravel units. Desirability is determined by the sand and gravel potential
attributes (Sg_xxxxx, as described above).
Limited refers to those units that do not contain sand and gravel or
where the deposits are insignificant. |
|
SGpot_plate1 |
|
Text, 15 |
Sand and Gravel |
Aggregate Potential
(Sand, Gravel, and Crushed Stone) that is depicted on Plate 1 (Significant
Aggregate Resources). Sand and Gravel
refers to those units with moderate or high potential of containing
significant sand and gravel resources. |
|
|
|
|
Bedrock |
Those units with
moderate or high potential of containing significant crushed stone resources. |
|
|
|
|
Sand and Gravel over
Bedrock. |
Those units with
moderate or high potential of containing significant sand and gravel
resources overlying areas with moderate or high potential of containing
significant crushed stone resources. |
|
|
|
|
Limited |
Those areas containing
low potential sand, gravel, and crushed stone resources, as well as area with
limited potential. |
|
Sg_min |
|
Number,3,0 |
Ex: 0,5,10,15,20,50 |
Describes the minimum
thickness of the sand and gravel unit. |
|
Sg_max |
|
Number,3,0 |
Ex: 0, 5, 10, 20, 30,
40, 50 |
Describes the maximum
thickness of the sand and gravel unit. |
|
Sgover_min |
|
Number,3,0 |
Ex: 0, 10,20 |
Describes the minimum
thickness of the overburden covering the sand and gravel. |
|
Sgover_max |
|
Number,3,0 |
Ex: 0, 3, 5, 10, 20, 30 |
Describes the maximum
thickness of the overburden covering the sand and gravel. |