FIELD OBSERVATIONS

Field | Description
Main ID Information | Metadata Updated 2007
Title | Benton County Aggregate Resource Evaluation - Field Observations
Filename | Fieldobs (ArcView Shapefile)
Abstract | This dataset includes information gathered in the field. Field work was completed in the fall of 2000 and Summer and Fall of 2001. It includes approximately 1325 field observation sites within Benton County. Includes a field description of each site, the dominant type of material encountered, the source of information, type of site, unit thickness, and overburden thickness.
Place Keywords | Benton County, Minnesota
Theme Keywords | Field Observations, Aggregate Resources, Surficial Geology
Time Period of Content | Fall 2000 and Summer and Fall 2001
Parent Theme | NA
Spatial Extent of the Data | Benton County, Minnesota
Contact Person | Jon Ellingson (or Renee Johnson)
Contact Person Organization/Division | Department of Natural Resources, Division of Lands and Minerals
Contact Person Position | Geologist or GIS Specialist
Contact Address | 500 Lafayette Road, Box 45
Contact City | St. Paul
Contact Zip Code | 55155-4045
Contact Voice Phone | 651-259-5959
Contact Fax Phone | 651-296-5939
Additional ID Information |
Originator | Department of Natural Resources, Division of Lands and Minerals, Mineral Potential Section
Purpose | To summarize the field observations. These observations were made to confirm air photo interpretations that identified potential aggregate bearing landforms.
Progress | Complete
Currentness Reference | All field observations were completed in the fall of 2000 and summer and fall of 2001.
Maintenance Frequency | None Planned
Access Constraints | NA
Use Constraints | NA
Associated Data Sets | Aggregate Resources of Benton County, Minnesota
Data Quality |
Attribute Accuracy | A GPS unit was used to determine the locations of the data points. These points were then downloaded and slightly revised based on field observations, topographic maps, and aerial photographs. The GPS unit (with differential correction) is accurate to approximately a few meters. The topographic maps are 1:24,000 and the aerial photographs are 1:40,000 scale.
Logical Consistency | NA
Completeness | The data points were gathered at the location where field observations took place.
Horizontal Positional Accuracy | GPS Unit with differential correction (+/- 2 meters)
Vertical Positional Accuracy |
Lineage | All point locations were recorded and downloaded from a GPS unit. These coordinates were then checked with field notes and topographic maps to assure accuracy. Some slight changes were made based on field notes.
Source Scale Denominator | 100
Spatial Reference |
Horizontal Coordinate Scheme | UTM
Ellipsoid | GRS80
Horizontal Datum | NAD83
Horizontal Units | meters
Distance Resolution | NA
Altitude Datum | NA
Altitude Units | NA
Depth Datum | NA
Depth Units | NA
UTM Zone Number | 15
Raster only |
Cell Width | NA
Cell Height | NA
Spatial Data Organization |
Geographic Reference for Tabular Data | NA
Native Dataset Environment | ArcView 3.1 and ArcInfo 8.0.2
Vendor Specific Object Type | Point
Tiling Scheme | County
Spatial Object Type | Point
Transfer Size | 275 kb
Entities -- Attributes |
Entity-Attribute Overview | A description of field observation sites, type of site, unit thickness, and overburden thickness.
Entity-Attribute Detailed Citation | ArcView specific fields include shape (i.e., feature type = point), area (0 for points), perimeter (0 for points), fieldobs_ (unique id for point, assigned by the software, fieldobs_i (an id usually assigned during theme creation). The field observation specific attributes are described in the table below.

Table Name | Field Name | Begin Column | Definition | Valid Values | Descriptions
fieldobs.dbf | Field_id |  | Text, 8 | Ex: A-34, B-65, T-23, etc… | Unique Identifiers used in the field, letters have no significance.
| Site_type1 |  | Text, 16 | Drill Hole | Test hole drilled with a Giddings Soil Probe.
|  |  |  | Excavation | Badger Holes, Trenches, Construction Areas, or Foundations
|  |  |  | Exposure | Bedrock exposures.
|  |  |  | Gravel Pit | Gravel Pits Exposing Sand and Gravel Material.
|  |  |  | Outcrop | Stream, Road-Cut, Bank, Judicial Ditch, or Slump.
|  |  |  | Quarry | An existing quarry exposing bedrock.
|  |  |  | Other | Observed Vegetative trends, story of a land owner, etc...
| Site_type2 |  | Text, 16 | Bank | Describes how the material was exposed. A bank of a cliff.
|  |  |  | Basement | Excavation of a basement by a backhoe.
|  |  |  | Construction | Mining for fill material and/or other construction.
|  |  |  | Ditch | Material exposed in a ditch due to a slump or landscaping that has removed vegetation.
|  |  |  | Foundation | A foundation was being dug, exposing material.
|  |  |  | Giddings Drill H | Test hole drilled with an 8 inch auger.
|  |  |  | Gravel Pit | Materials exposed in gravel pit.
|  |  |  | Judicial Ditch | Materials exposed in manmade ditch.
|  |  |  | Observation | Talked to individual.
|  |  |  | Pit | Small pit/Water hole
|  |  |  | Quarry | Bedrock units exposed in a quarry.
|  |  |  | River Cut | Stream exposed an area.
|  |  |  | Road Cut | Materials exposed in a road cut
|  |  |  | Road Cut Gully | Materials exposed in gullies along road cuts.
|  |  |  | Rock Pile | Large rock Pile – Possibilities for rip-rap material.
|  |  |  | Sand Pit | Sand Pit.
|  |  |  | Stream | Exposure due to stream cut.
|  |  |  | Surface | Exposures of bedrock on the surface.
|  |  |  | Trench | Trenches for pipelines, tiling, cables, etc.
|  |  |  | Water Hole | Livestock Water hole or recreation pond being dug.
| Material_1 |  | Text, 16 | Ex: Sand, Gravel, Clay, Silt, Limestone, Sandstone. | Describes the primary type of material encountered at each observation site.
| Material_2 |  | Text, 16 | Ex: Sand, Gravel, Clay, Silt, Limestone, Sandstone. | Describes the secondary (not primary) type of material at each observation site.
| Fielddesc |  | Text, 80 | Ex: Drill Hole (0-9 ft) 0-6 Till, 6-9 Gravel. | A short field description of the observation site.
| Unitthick |  | Text, 8 | Ex:0, 4, 5, 8, 12, >3, >5, >10, etc... | A description of the thickness of the unit in feet, with “<“ or “>” modifiers.
| Overthick |  | Text, 8 | Ex: <3, 6, <5, >5, >20, etc... | A description of the thickness of the overburden covering the unit, with “<“ or “>” modifiers.
| Thickmod |  | Text, 4 | > | Modifies the Thick (i.e., Thickness field). Greater Than
|  |  |  | < | Less Than.
| Thick |  | Number,3,0 | Ex: 10, 15, 30, 40 | Describes the thickness of the unit at the observation site in feet.
| Overmod |  | Text, 4 | > | Modifies the Over (Overburden Field). Greater Than.
| Overmin |  | Number,3,0 | Ex: 0, 2, 3, 5. | Describes the minimum thickness of overburden (material) covering a unit.
| Overmax |  | Number,3,0 | Ex: 0, 6, 10. | Describes the maximum thickness of overburden (material) covering a unit.