FIELD OBSERVATIONS



Field

Description

Main ID Information

Metadata Updated 2007

Title

Blue Earth 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 summer and fall of 1998. It includes approximately 450 field observation sites within Blue Earth County. Includes a field description of each site, the dominant type of material encountered, the source of information, type of site, unit thickness, overburden thickness, tells if it was sampled or not, and gives the gravel percent for all sampled deposits.

Place Keywords

Blue Earth County, Minnesota

Theme Keywords

Field Observations, Aggregate Resources, Surficial Geology

Time Period of Content

Summer and Fall 1998

Parent Theme

NA

Spatial Extent of the Data

Blue Earth County, Minnesota

Contact Person

Aggregate Resources Mapping Program

Contact Person Organization/Division

Department of Natural Resources, Division of 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 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 summer & fall field session of 1998 (June-October).

Maintenance Frequency

None Planned

Access Constraints

NA

Use Constraints

NA

Associated Data Sets

Aggregate Resources of Blue Earth County, Minnesota

Data Quality

 

Attribute Accuracy

A GPS unit was used to determine the locations of the data points, these points were 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 (at a distance measurements/observations).

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 ArcInfo7.2.1

Vendor Specific Object Type

Point

Tiling Scheme

County

Spatial Object Type

Point

Transfer Size

106 kb

Entities -- Attributes

 

Entity-Attribute Overview

A description of field observation sites, type of site, unit thickness, overburden thickness, and if a sample was collected or not.

Entity-Attribute Detailed Citation

See table below: Arcview specific fields include shape (i.e., feature type = point), area (0 for points), perimeter (0 for points), filename (unique id for point, assigned by the software), filename_i or filename_id if filename is less than 8 characters (an id usually assigned during theme creation).





Table Name

Field Name

Begin Column

Definition

Valid Values

Descriptions

fieldobs.dbf

Field_stop

 

Text, 8

Ex: J-1, R-3

Unique Identifiers used in the field, letters have no significance.

 

Site_type1

 

Text, 16

Badger Hole

Describes how the material was exposed. Badger dug several feet into the surficial material.

 

 

 

 

Bank

A bank of a cliff.

 

 

 

 

Basement

Excavation of a basement by a backhoe.

 

 

 

 

Construction

Mining for fill material and/or other construction.

 

 

 

 

Ditch

Material with no vegetation along road.

 

 

 

 

Drill Hole

Test hole drilled with a 4 inch auger.

 

 

 

 

Foundation

A foundation was being dug, exposing material.

 

 

 

 

Gravel Pit

Materials exposed in gravel pit.

 

 

 

 

Gully

Materials exposed in gully due to erosion.

 

 

 

 

Judicial Ditch

Materials exposed in manmade ditch.

 

 

 

 

Quarry

Bedrock units exposed in a quarry.

 

 

 

 

Road Cut

Materials exposed in a road cut

 

 

 

 

Road Cut Gully

Materials exposed in gullies along road cuts.

 

 

 

 

Slump

Material exposed on steep slopes due to slumping.

 

 

 

 

Stream

Material exposed in stream cuts along rivers.

 

 

 

 

Surface

Exposures of bedrock on the surface.

 

 

 

 

Trench

Trenches for pipelines, tiling, cables, etc.

 

Site_type2

 

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.

 

Material

 

Text, 16

Ex: Sand, Gravel, Clay, Cobbles, Silt, Limestone, Sandstone.

Describes the dominant 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: 5, 10, >15, <30

A description of the thickness of the unit in feet, with "<" or ">" modifiers.

 

Overthick

 

Text, 8

Ex: 5, 10, >30, <3

A description of the thickness of the overburden covering the unit, with "<" or ">" modifiers.

 

Unitsamp

 

Text, 4

Y

Y=Yes the site was sampled.

 

 

 

 

N

N=No the site was not sampled.

 

Gravpct

 

Number,3,0

Ex: 23, 32, 45, 50

The percentage of gravel found within the sample. Sieve analysis completed.

 

Thickmod

 

Text, 4

>

Modifies the Thick (Thickness Field). Greater Than

 

 

 

 

<

Less Than.

 

Thick

 

Number,3,0

Ex: 10, 15, 30, 40

Described the thickness of the unit at the observation site in feet.

 

Overmod

 

Text, 4

<

Modifies the Over (Overburden Field). Greater Than.

 

 

 

 

<

Less Than

 

Over

 

Number,3,0

Ex: 3, 5, 10, 15,

Describes the thickness of overburden (material) covering a unit.