Stratigraphy

Start Depth
End Depth
Stratigraphic Unit
Start Depth: 0.00 ft
End Depth: 90.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
0.00 ft
End Depth
90.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Till 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 90.00 ft
End Depth: 260.00 ft
Unit: Silurian 
System
Silurian 
Series
 
Group
 
Formation
 
Member
 
Submember
 
Start Depth
90.00 ft
End Depth
260.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Bedrock Surface - Complete Penetration, No Gaps 
Primary Lithology
Dolomite 
Percent
Secondary Lithology
Chert/Chalcedony 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 260.00 ft
End Depth: 380.00 ft
Unit: Brainard Shale 
System
Ordovician 
Series
 
Group
 
Formation
Maquoketa 
Member
Brainard Shale 
Submember
 
Start Depth
260.00 ft
End Depth
380.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Shale 
Percent
Secondary Lithology
Dolomite 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 380.00 ft
End Depth: 396.00 ft
Unit: Ft. Atkinson Limestone 
System
Ordovician 
Series
 
Group
 
Formation
Maquoketa 
Member
Ft. Atkinson Limestone 
Submember
 
Start Depth
380.00 ft
End Depth
396.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Dolomite 
Percent
Secondary Lithology
Shale 
Percent
Tertiary Lithology
Chert/Chalcedony 
Percent
Comments
Start Depth: 396.00 ft
End Depth: 425.00 ft
Unit: Clermont Shale 
System
Ordovician 
Series
 
Group
 
Formation
Maquoketa 
Member
Clermont Shale 
Submember
 
Start Depth
396.00 ft
End Depth
425.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Shale 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 425.00 ft
End Depth: 450.00 ft
Unit: Elgin Limestone 
System
Ordovician 
Series
 
Group
 
Formation
Maquoketa 
Member
Elgin Limestone 
Submember
 
Start Depth
425.00 ft
End Depth
450.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Partial Penetration (Base Not Met), No Gap At Top 
Primary Lithology
Dolomite 
Percent
Secondary Lithology
Shale 
Percent
Tertiary Lithology
 
Percent
Comments