Table Name

Field Name

Begin Column

Definition

Valid Values

Descriptions

carlcsp.dbf

OBJECTID

 

Number,4,0

Ex: 1,2,9

Unique Number for each crushed stone potential polygon

 

 

POTENTIAL

 

Text, 75

See Below

Significant Potential for Crushed Stone Resources

Basalt and metavolcanic formations (e.g., metagabbro) suitable for crushing. These units are inferred to be relatively thick (greater than 100 feet), with overburden thicknesses ranging from 0 to 20 feet. No quality tests have been conducted on these rock types within Carlton County.

Nonsignificant Potential for Crushed Stone Resources

Bedrock geology units of sedimentary rocks, metamorphosed sedimentary rocks, and volcanic rocks that are not suitable for crushing with varying degrees of overburden.  Or basalt and metavolcanic formations (e.g., metagabbro) that are suitable for crushing however have overburden greater than 10 feet for metavolcanics or 50 feet for basalt. 

 

 

CLASS

 

Text, 75

See Below

Moderate Potential for Crushed Stone Resources

Basalt exposed or buried beneath 0 to 20 feet of overburden and metavolcanic formations exposed or buried beneath 0 to 10 feet of overburden.  Based on generalized rock quality assessments, these units have a moderate to moderately high probability of providing material suitable for crushed stone aggregates.

Low Potential for Crushed Stone Resources

Basalt buried beneath 50 feet of overburden and metavolcanics buried beneath 10 to 20 feet of overburden.  Based on generalized rock quality assessments, these units have a moderate probability of providing material suitable for crushed stone aggregates.

Limited Potential for Crushed Stone Resources

Sandstone, metasediments and metavolcanics exposed or buried under overburden.  Based on the rock types shown on existing bedrock geologic maps, these units have a low probability of providing material suitable for crushed stone aggregates.

 

 

OVERBURDEN

 

Text, 15

See Below

0 - 10

0 – 10 feet of overburden

0 - 20

0 – 20 feet of overburden

10 - 20

10 - 20 feet of overburden

0-50

50 feet of overburden

 

QUALITY

 

Text, 20

Moderately High, Moderate, Poor

The relative degree of quality that a bedrock unit can be used for crushed stone.

 

PROBABLTY

 

Text, 20

Moderately High, Moderate, Low

The relative degree of certainty that crushed stone exists within a unit.  Based on air photo interpretations, field observations, CWI, drilling, etc.  Each unit is relative to the other units and range from moderately high to low.

 

BDRK_UNIT

 

Text, 50

See Below

Describes the Bedrock Units most associated with the mapping units.

 

 

Chengwatana Basalt

Includes rocks that have similar chemical and physical properties as basalt.  Known quarry in Pine County within this formation.  Generally suitable for crushed stone.

 

 

Metavolcanic

Includes rocks that have similar chemical and physical properties as metagabbro as well as metamorphosed basalt, known as metabasalt.  Can be suitable for crushed stone depending on degree of metamorphism.

 

 

Metasediments, Metavolcanics, Sandstone

Includes rocks that have similar chemical and physical properties as metavolcanics, metasediments (e.g., schist, slate, phyllite), and sandstone.  Although these units can be suitable for crushed stone, within Carlton County and Fond du Lac Reservation these units have poor quality based on their degree of metamorphism and competency.

Sandstone

A sedimentary rock that is generally not suitable for crushed stone potential.