Geologic Units

Quaternary alluvial deposits
Quaternary surficial cover, fluveolian cover on Snake River Plain, alluvial fans (Snake River Group)
Lake Bonneville deposits
Pliocene and Upper Miocene stream and lake deposits (Salt Lake Formation, Starlight Formation, Idaho Group)
Silurian sedimentary rocks 
Ordovician sedimentary rocks
Cambrian sedimentary rocks  
Ordovician, Cambrian, and Neoproterozoic sedimentary rocks, Bannock and Portneuf Ranges
Cambrian to Neoproterozoic Brigham Group

  Map Key
Geologic units with unit designation.
Normal Fault: certain; dashed where approximately located; dotted where concealed.
Thrust Fault: certain; dashed where approximately located; dotted where concealed.
Detachment Fault: certain; dashed where approximately located; dotted where concealed.
Interstate Route.
U.S. Route.
State Route.
Location of Rockwalk rock from the county.
Cities.
Feature location.

Additional Reading


Rocks Rails and Trails: pages
Introduction to the Geology of South & East Idaho
Introduction to Geologic Diagrams
Geologic cross sections
Relations between Geology, Topography and Drainage Systems in Idaho
Drainage and mountain range map for eastern Idaho
Table of Geologic Events in Southern Idaho
Drainage Systems, Rails and Trails
Geologic Provinces along the Oregon Trail
Rocks of the Eastern Idaho Mountains
The Thrust Belt of Southeastern Idaho
Views of Thrust Faults
Basin and Range Faulting
Lake Bonneville and its Flood
Disposal of Wastes at the Idaho National Engineering & Environmental Laboratory
References on Idaho Geology
Section 3, History of Eastern Idaho
Section 3, Chapter 8 -"Famous Potatoes" Agriculture & Irrigation
Section 4, Chapter 14 -Cache Valley
Bear River Landslide Complex

Click here to see a correlation of geologic units, and the associated time scale.

Click here for a printable version of this map.

Click on the button below to search the IdahoGeologic Survey's index of Geologic Maps