AGGREGATE POTENTIAL:  For the purpose of this study, aggregate potential is defined as an assessment of the relative probability that an
aggregate deposit exists within a given area, with almost all emphasis placed upon geologic evidence, parameters, and interpretation at the 
reconnaissance level, rather than upon economic feasibility evaluation or other parameters.  This assessment does not imply that economic 
aggregate deposits exist everywhere within a given map unit designated as "Potential Aggregate Resources".  Rather, that within such a map 
unit, geologic processes were active that could have created aggregate deposits at specific sites.  Geologic measurements of aggregate deposits 
remain constant, but economic criteria and environmental permitting vary across time and place.  Important site-specific factors such as 
ownership, zoning, protected waters and wetlands, environmental permitting, distance to markets, royalties, and individual site characteristics, 
such as access, all contribute to the final "potential" of a specific parcel; however, these factors were not included in this study.

POTENTIAL SAND AND GRAVEL RESOURCES:  Geologic units that are inferred to contain moderately to highly desirable sand 
and gravel deposits.  These units exhibit the geologic characteristics that typically produce sand and gravel deposits.  Existing 
gravel pits and MN/DOT aggregate sources lying within these units indicate identified or known resources.  The geologic units 
having potential for sand and gravel include alluvial features (flood plains, terraces, and fans), glacial outwash features (channels, 
terraces, and fans), and ice-contact features (eskers and kames).  These units typically contain sorted sand and gravel with little 
silt or clay.

POTENTIAL CRUSHED STONE RESOURCES:  Bedrock formations that consist of moderately and highly desirable granite that is 
suitable for crushing.  These granite units consist of some of the highest quality crushed stone resources in the state of Minnesota.  
The units are inferred to be very thick (50 to several hundred feet), with overburden thicknesses of less than 30 feet.  Quarries 
located within these units indicate identified or known resources.  These bedrock resources are most commonly at or near the 
surface in the southwest and northeast parts of the county. 

LIMITED POTENTIAL FOR AGGREGATE RESOURCES:  Units that generally have less desirable, or little or no potential for 
aggregate resources.  These units exhibit geologic characteristics that are typically not consistent with significant aggregate 
deposits.  The geologic units that have less desirable potential include alluvial features (beaches and flood plains), glacial outwash 
features (outwash channels, fans, and deltas), and ice-contact features (eskers and kames) that are typically small, thin, or have 
too fine of a material to be of commercial value.  The geologic units having limited potential include eolian (wind-blown), lacustrine 
(lake plains), morainic (till), small alluvial deposits, and bedrock with overburden thicknesses greater than 50 feet.  These units 
typically contain clay, silt, fine sand, unsorted sediments (specifically in till), or very thin layers of sand and gravel.  The units may 
include aggregate deposits that are too small to be mapped.


IDENTIFIED AGGREGATE RESOURCES:  Areas where aggregate resources (sand, gravel, and/or crushed stone) have been or are currently 
being mined.  Pit and quarry locations have been gathered from several different reference sources, including topographic maps, aerial 
photographs, county records, county highway department maps, soil surveys, MN/DOT files, fieldwork, gravel operators, and other 
miscellaneous sources.  The pits and quarries range in size from less than 1 acre to greater than 50 acres and may be active, inactive,
depleted, or reclaimed.  The aggregate quality of the pits varies.
Gravel Pits:  Locations were gathered from several different reference sources.  Any given pit may be active, inactive, 
depleted, or reclaimed.

Gravel Pits - MN/DOT files:  Locations gathered from ASIS, the Minnesota Department of Transportation's Aggregate 
Source Information System listing of aggregate sources.  Test hole logs, sieve, and quality test data are available.

Quarries:  Granite quarries from several different reference sources.  Any given unit may be active, inactive, depleted, 
or reclaimed.


OTHER FEATURES:
WETLANDS:  Wetland area.

WATER:  Lakes or rivers.

