Table Name

Field Name

Begin Column

Definition

Valid Values

Descriptions

millfobs.dbf

Field_Id

 

Text, 8

Ex: AA-015, CD-112

Unique identifiers used in the field, letters signify an assigned field work quad map

 

Sitetype_1

 

Text, 20

See Below

 

 

 

 

 

Borrow Pit

A pit usually dug in material that is not sand and gravel.

 

 

 

 

Drill Hole

Test hole drilled with a Giddings Soil probe.

 

 

 

 

Excavation

Badger holes, trenches, construction areas, or foundations

 

 

 

 

Exposure

Outcrop of material from erosional processes

 

 

 

 

Gravel Pit

Gravel pits exposing sand and gravel material.

 

 

 

 

Other

Based on communication

 

 

 

 

Outcrop

A bedrock outcrop

 

Sitetype_2

 

Text, 20

See Below

Further description of the observation site specified in Site_type1.

 

 

 

 

Animal Hole

A hole dug by an animal which exposes sediment

 

 

 

 

Back Hoe

A hole dug by a backhoe.

 

 

 

 

Basement

Excavation of a basement.

 

 

 

 

Borrow Pit

A mined pit for construction material

 

 

 

 

Cemetery

Excavation in cemetery

 

 

 

 

Communication

Contact with landowners, drillers, and experts verifying well records.

 

 

 

 

Construction

Mining or digging due to construction.

 

 

 

 

Ditch

Material exposed in a ditch due to a slump or landscaping that has removed vegetation.

 

 

 

 

Drill Hole

Material extracted from drilling. Test hole drilled with an 8-inch auger.

 

 

 

 

Fence Post

Exposure in and around fence post.

 

 

 

 

Generalization

A general observation made about the landscape, vegetation, and other features.

 

 

 

 

Gravel Pit

Materials exposed in gravel pit.

 

 

 

 

Gully

Material exposed in a gully.

 

 

 

 

Outcrop

Exposure of bedrock outcrop.

 

 

 

 

Pond

Material exposed on banks of pond.

 

 

 

 

Quarry

Materials exposed in quarry.

 

 

 

 

River Cut

Stream exposed an area.

 

 

 

 

Road Cut

Materials exposed in a road cut.

 

 

 

 

Stream

Exposure of sediment due to erosion and down cutting of streams and rivers.

 

 

 

 

Surface

Exposures of bedrock/material on the ground surface.

 

 

 

 

Telephone Pole

Sediment exposed due to drilling and installation of new telephone poles.

 

 

 

 

Trench

Any trench exposure of material.

 

 

 

 

Utility Construction

Sediment observed by the excavation and work on utility boxes.

 

Material_1

 

Text, 20

See Below

Describes the primary type of material encountered at each observation site and does not necessarily reflect stratigraphic order.

 

 

 

 

Alluvium

Sediment deposited by a river or stream.  Contains sediment particles ranging from clay, silt, sand, and gravel.

 

 

 

 

Clay

Clay is a very fine-grained sediment that is less than.0.004 mm  in size.

 

 

 

 

Des Moines Till

Till is unsorted sediment that is directly deposited by glacial ice.  Des Moines Till is characterized by a tan, silty loam that contains particles of shale and limestone.  The Des Moines Lobe is a glacial lobe that flowed into Minnesota from the northwest.

 

 

 

 

Granite

An intrusive, felsic igneous rock that has a medium to coarse texture.

 

 

 

 

Granite/Gneiss

An intrusive, felsic igneous rock that has a medium to coarse texture and has been slightly metamorphosed.

 

 

 

 

Organics

Soil that contains decaying organic matter.

 

 

 

 

Sand

Sand is composed of rocks and minerals that range in diameter from 0.0625 to 2 mm.

 

 

 

 

Sand and Gravel

Sediment that contains a mixture of rocks in varying sizes ranging from 0.0625 to 64 mm.   This description is given to sediment that contains greater than 15% by volume gravel.

 

 

 

 

Sand with Gravel

Sediment that contains a mixture of rocks in varying sizes ranging from 0.0625 to 64 mm.   This description is given to sediment that contains less than 15% by volume gravel.

 

 

 

 

Sand/Silt/Gravel

Sediment that contains a mixture of rocks in varying sizes ranging from 0.004 to 64 mm.   This description is given to sediment that contains mostly sand with some silt and gravel.

 

 

 

 

Sandy Alluvium

Stream and river sediment that consists predominantly of sand.

 

 

 

 

Sandy Silt

Silt that contains a portion of fine sand.

 

 

 

 

Sandy Till

Till that contains a high percentage of sand.

 

 

 

 

Silt/Sand/Gravel

Sediment that contains a mixture of rocks in varying sizes ranging from 0.004 to 64 mm.   This description is given to sediment that contains a high amount of silt as wells as sand and gravel

 

 

 

 

Silty Sand

Sand that contains some silt.

 

 

 

 

Till

A term used to describe the unsorted sediment deposited by glaciers- contains a mixture of clay, silt, sand, gravel and boulders.

 

Material_2

 

Text, 20

See Below

Describes the secondary (not primary) type of material at each observation site.

 

 

 

 

Des Moines Lobe Till

Till is unsorted sediment that is directly deposited by glacial ice.  Des Moines Till is characterized by a tan, silty loam that contains particles of shale and limestone.  The Des Moines Lobe is a glacial lobe that flowed into Minnesota from the northwest.

 

 

 

 

Sand

Sand is composed of rocks and minerals that range in diameter from 0.0625 to 2 mm.

 

 

 

 

Sand and Gravel

Sediment that contains a mixture of rocks in varying sizes ranging from 0.0625 to 64 mm.   This description is given to sediment that contains greater than 15% by volume gravel.

 

 

 

 

Sandy Till

Till that contains a high percentage of sand.

 

 

 

 

Silt

A fine grained sediment that has a diameter between 0.004 to 0.0625 mm.

 

 

 

 

Superior Lobe Till

Unsorted sediment deposited from glacial ice flowing from the Lake Superior Basin.  Typically consists of red-brown, sand loam containing rhyolites, basalts, and other North Shore Minnesota rock types.

 

 

 

 

Till

A term used to describe the unsorted sediment deposited by glaciers- contains a mixture of clay, silt, sand, gravel and boulders.

 

Fielddesc

 

Text, 80

Ex: Drill Hole (0-9 ft)  0-6 Till, 6-9 Gravel.

A short field description of the observation site.

 

Thickness

 

Text, 15, 0

>7, 5-15, NA

A description of thickness of the geological unit.  NA indicates Not Available

 

Thick_mod

 

 

Text, 1

See Below

Modifies the thick_min or thick_max (i.e., Thickness field). 

 

 

 

 

>

Greater Than

 

 

 

 

<

Less Than.

 

 

 

 

~

Approximately.

 

Thick_min

 

Number, 6, 0

Ex: 2, 6, 50, -999

The minimum thickness of the observed unit.  (–999 value is null)

 

Thick_max

 

Number, 6, 0

Ex: 20, 50, -999

The maximum thickness of the observed unit.  (–999 value is null)

 

Overburden

 

Text, 15, 0

5-15+, >5, ~10, NA

A description of the overburden covering an aggregate unit.  NA indicates Not Available

 

Ob_mod

 

Text, 1

See Below

Modifies the Ob_min or Ob_max (i.e., Thickness field). 

 

 

 

 

>

Greater Than

 

 

 

 

<

Less Than.

 

 

 

 

~

Approximately.

 

Ob_rmin

 

Number, 6, 0

Ex: 2, 9, 35, -999

A description of the minimum thickness of the overburden covering the unit.  (–999 value is null)

 

Ob_max

 

Number, 6, 0

Ex: 3, 5, 10, -999

A description of the maximum thickness of the overburden covering the unit.  (–999 value is null)

 

Sampled

 

Text, 3

Yes or No

Indicates whether the material was sampled.  Not all sampled material was tested.

 

Gravel_pct

 

Number, 2, 0

Ex. 44

Percent gravel retrieved from the sieve analysis on sampled units.  (–999 value is null)