Stratigraphy

Start Depth
End Depth
Stratigraphic Unit
Start Depth: 0.00 ft
End Depth: 10.00 ft
Unit: Peoria 
System
Quaternary 
Series
Pleistocene Series 
Group
Wisconsinan Episode 
Formation
Peoria 
Member
 
Submember
 
Start Depth
0.00 ft
End Depth
10.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Loess 
Percent
100 
Secondary Lithology
Unknown 
Percent
Tertiary Lithology
Unknown 
Percent
Comments
Start Depth: 10.00 ft
End Depth: 20.00 ft
Unit: Unknown 
System
Unknown 
Series
 
Group
 
Formation
 
Member
 
Submember
 
Start Depth
10.00 ft
End Depth
20.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Sand And Gravel 
Percent
100 
Secondary Lithology
Unknown 
Percent
Tertiary Lithology
Unknown 
Percent
Comments
Start Depth: 20.00 ft
End Depth: 90.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
20.00 ft
End Depth
90.00 ft
Contact Accuracy
Top Accurate, Base Less Accurate - (Poor Samples, Gap At Contact) 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Till - Oxidized And Unleached 
Percent
100 
Secondary Lithology
Unknown 
Percent
Tertiary Lithology
Unknown 
Percent
Comments
Start Depth: 90.00 ft
End Depth: 100.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
90.00 ft
End Depth
100.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Till - Unoxidized And Unleached 
Percent
70 
Secondary Lithology
Till - Oxidized And Unleached 
Percent
30 
Tertiary Lithology
 
Percent
Comments
Start Depth: 100.00 ft
End Depth: 125.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
100.00 ft
End Depth
125.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Till - Unoxidized And Unleached 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 125.00 ft
End Depth: 130.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
125.00 ft
End Depth
130.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Silt 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 130.00 ft
End Depth: 135.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
130.00 ft
End Depth
135.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Till - Unoxidized And Unleached 
Percent
100 
Secondary Lithology
Unknown 
Percent
Tertiary Lithology
Unknown 
Percent
Comments
Start Depth: 135.00 ft
End Depth: 160.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
135.00 ft
End Depth
160.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, Gaps, Top & Base Defined 
Primary Lithology
Till - Unoxidized And Unleached 
Percent
55 
Secondary Lithology
Till - Oxidized And Unleached 
Percent
45 
Tertiary Lithology
 
Percent
Comments
Start Depth: 160.00 ft
End Depth: 175.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
160.00 ft
End Depth
175.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, No Gaps 
Primary Lithology
Till - Unoxidized And Unleached 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 175.00 ft
End Depth: 190.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
175.00 ft
End Depth
190.00 ft
Contact Accuracy
Base Accurate, Top Less Accurate - (Poor Samples, Gap At Contact) 
Penetration
Complete Penetration, Gap At Base 
Primary Lithology
Till - Oxidized And Unleached 
Percent
60 
Secondary Lithology
Till - Unoxidized And Unleached 
Percent
30 
Tertiary Lithology
Sand 
Percent
10 
Comments
Start Depth: 190.00 ft
End Depth: 310.00 ft
Unit: Pre-Illinoian 
System
Quaternary 
Series
Pleistocene Series 
Group
Pre-Illinoian 
Formation
 
Member
 
Submember
 
Start Depth
190.00 ft
End Depth
310.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, Gap At Top 
Primary Lithology
Till - Unoxidized And Unleached 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 310.00 ft
End Depth: 385.00 ft
Unit: Fort Benton ("Lower Colorado ") 
System
Cretaceous 
Series
 
Group
Fort Benton ("Lower Colorado ") 
Formation
 
Member
 
Submember
 
Start Depth
310.00 ft
End Depth
385.00 ft
Contact Accuracy
Top Accurate, Base Less Accurate - (Indistinct Lithologic Break) 
Penetration
Bedrock Surface - Complete Penetration, Gaps, Top & Base Defined 
Primary Lithology
Shale 
Percent
100 
Secondary Lithology
 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 385.00 ft
End Depth: 481.00 ft
Unit: Dakota 
System
Cretaceous 
Series
 
Group
Fort Benton ("Lower Colorado ") 
Formation
Dakota 
Member
 
Submember
 
Start Depth
385.00 ft
End Depth
481.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Complete Penetration, Gaps, Top & Base Defined 
Primary Lithology
Sandstone 
Percent
Secondary Lithology
Shale 
Percent
Tertiary Lithology
 
Percent
Comments
Start Depth: 481.00 ft
End Depth: 509.00 ft
Unit: Sioux Quartzite 
System
Proterozoic 
Series
 
Group
 
Formation
Sioux Quartzite 
Member
 
Submember
 
Start Depth
481.00 ft
End Depth
509.00 ft
Contact Accuracy
Top & Base Accurate For Sample 
Penetration
Partial Penetration (Base Not Met), No Gap At Top 
Primary Lithology
Quartzite 
Percent
Secondary Lithology
Clay 
Percent
Tertiary Lithology
 
Percent
Comments