COUNTY WELL INDEX (CWI) - GEOLOGICAL DESCRIPTIONS



Field

Description

Main ID Information

Metadata Updated 2007

Title

Nicollet County Aggregate Evaluation -CWI Geological Descriptions Table

Filename

Cwi_geod (DataBase File)

Abstract

This dataset consists of the geological description used within the CWI database. It lists the unique identifier, the depth to the top of interval and the driller's description of the material encountered.

Place Keywords

Nicollet County, Minnesota

Theme Keywords

CWI, County Well Index, Geological Descriptions

Time Period of Content

Downloaded in 1999

Parent Theme

NA

Spatial Extent of the Data

Nicollet County, Minnesota

Contact Person

Aggregate Resource Mapping Program (Geologist or GIS Specialist)
Minnesota Department of Natural Resources, Division of Lands and Minerals
500 Lafayette Road, Box 45

St. Paul, MN 55155-4045
Phone: 651-259-5959
FAX:  651-296-5939
E-mail: AggregateMap@dnr.state.mn.us

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

Minnesota Geological Survey

Purpose

This data set was used to help interpret the aggregate resources, surficial geology, and geological history of Nicollet County. This dataset consists of the geological description used within the CWI database. It lists the unique identifier, the depth to the top of interval and the drillers description of the material encountered.

Progress

Complete

Currentness Reference

1999

Maintenance Frequency

None planned

Access Constraints

NA

Use Constraints

NA

Associated Data Sets

CWI99PT3 - one-to-many (cwi99pt3-to-cwi_geod) - relate on unique_no.

Data Quality

 

Attribute Accuracy

These descriptions were made by several different drillers, geologists, etc. The information within them ranges from very good to very poor. The thicknesses are generally estimated to within a few feet and the descriptions may vary from hole to hole due to many different individuals completing the logging.

Logical Consistency

NA

Completeness

Some of the geological descriptions are very complete other are very vague. Ex: the detailed descriptions may be broken down every 5 to 10 feet describing the glacial material and bedrock formations, others may just say 0-240 glacial drift, 240-360 sandstone.

Horizontal Positional Accuracy

NA

Vertical Positional Accuracy

NA

Lineage

These descriptions were made by several different drillers, geologists, etc. The information within them ranges from very good to very poor. The thicknesses are generally estimated to within a few feet and the descriptions may vary from hole to hole due to many different individuals completing the logging.

Source Scale Denominator

NA

Spatial Reference

 

Horizontal Coordinate Scheme

NA

Ellipsoid

NA

Horizontal Datum

NA

Horizontal Units

NA

Distance Resolution

NA

Altitude Datum

NA

Altitude Units

NA

Depth Datum

Drilled and logged wells.

Depth Units

Feet

UTM Zone Number

NA

Raster only

 

Cell Width

NA

Cell Height

NA

Spatial Data Organization

 

Geographic Reference for Tabular Data

These points are located throughout Nicollet County (usually near farms).

Native Dataset Environment

ArcView 3.1 / ArcInfo 8.0.2

Vendor Specific Object Type

NA

Tiling Scheme

County

Spatial Object Type

Point

Transfer Size

374 kb

Entities -- Attributes

 

Entity-Attribute Overview

This dataset consists of the geological description used within the CWI database. It lists the unique identifier, the depth to the top of interval, and the driller's description of the material encountered.

Entity-Attribute Detailed Citation

See table below:





Table Name

Field Name

Begin Column

Definition

Valid Values

Descriptions

cwi_geod.dbf

Unique_no

 

Text, 6

Ex: 102365

This is the unique well identifier used by the MGS to reference the well (Relate item with cwi99pt3).

 

Dpth_topi

 

Number,11,0

Ex: 2, 4, 8, 240

Depth to the top of interval.

 

Drill_desc

 

Text, 33

Ex: Clay, Sand , Gravel

Drillers log - geological description