Table Name

Field Name

Begin Column

Definition

Valid Values

Descriptions

millcsp.dbf

OBJECTID

 

Number,4,0

Ex: 1,2,9

Unique Number for each crushed stone potential polygon

 

 

Potential

 

Text, 10

See Below

 

 

 

 

 

Potential for Crushed Stone Resources

Granite and other crystalline bedrock formations (e.g., gneiss, monzonite, gabbro, and basalt) suitable for crushing. These units are inferred to be relatively thick (greater than 100 feet), with overburden thicknesses ranging from 0 to 50 feet. Quarries located within these units are identified or known resources.

 

 

 

 

Limited Potential for Crushed Stone Resources

Bedrock geology units of sedimentary rocks, metamorphic sedimentary rocks, schist, and shear zones that are not suitable for crushing with varying degrees of overburden.  Or Granite and other crystalline bedrock formations (e.g., gneiss, monzonite, gabbro, and basalt) that are suitable for crushing however have overburden greater than 50 feet or very low to moderately low probability or certainty that the bedrock unit is suitable for crushing or that the overburden is less than 50 feet. 

 

 

Class

 

Text, 17

See Below

 

 

 

 

 

High Potential for Crushed Stone Resources

Granite and other crystalline bedrock formations exposed at the land surface or buried by less than 15 feet of overburden.  Based on the rock types shown on existing bedrock geologic maps, these units have a moderate to high probability of providing material suitable for crushed stone aggregates.

 

 

 

 

Moderate Potential for Crushed Stone Resources

Granite and other crystalline bedrock buried beneath 15 to 30 feet of overburden.  Based on the rock types shown on existing bedrock geologic maps, these units have a moderately low to high probability of providing material suitable for crushed stone aggregates.

 

 

 

 

Low Potential for Crushed Stone Resources

Granite and other crystalline bedrock buried beneath 30 to 50 feet of overburden.  Based on the rock types shown on existing bedrock geologic maps, these units have a low to moderately low probability of providing material suitable for crushed stone aggregates.

 

 

Overburden

 

Text, 10

See Below

 

 

 

 

 

0 - 15

0 – 15 feet of overburden

 

 

 

 

15 - 30

15 – 30 feet of overburden

 

 

 

 

30 - 50

30 - 50 feet of overburden

 

 

 

 

50+

50 + feet of overburden

 

Quality

 

Text, 20

High, Low, Moderately Low.

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

 

Probablty

 

Text, 20

Very High, High, Moderately High, Moderate, Moderately Low, Low, Very Low

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

 

Bdrk_Unit

 

Text, 20

See Below

Describes the Bedrock Units most associated with the mapping units

 

 

 

 

Granitic Rocks

Includes rocks that have similar chemical and physical properties as granite.  General suitable for crushed stone

 

 

 

 

Granitic Rocks and Gneiss

Includes rocks that have similar chemical and physical properties as granite as well as metamorphosed granite, known as gneiss.   Generally suitable for crushed stone.

 

 

 

 

Granitic Rocks and Mafics

Includes rocks that have similar chemical and physical properties as granite.  These rocks include mafic rocks like gabbro and basalt.  Can be suitable for crushed stone but depending on the degree of fracture.

 

 

 

 

Mafic to Ultramafic Intrusive  Rocks

Rocks like gabbro and basalt that intrude other rock types. Can be suitable for crushed stone but depending on the degree of fracture.

 

 

 

 

Schist

A metamorphic rock that is not suitable for crushed stone potential.

 

 

 

 

Shear Zone

A structural feature containing rocks that are fractured, metamorphosed, and not suitable for crushed stone.