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)