This page is a general summary of the tectonic environment that existed in Utah over the past billion years.  The arrows show the direction of crustal stresses that were acting upon Utah at different times.  The blue colors represent water with the brown tones being dry ground.  Notice the variations in size and shape of the state throughout it's geologic past.  Each illustration is linked to its page in the site.  The square box represents the location of Rock Canyon on each map.

Precambrian Glaciers

Cambrian Ocean

Mississippian Sea


3,000 - 1,000 m.y. ago

Archean - Early Proterozoic

Collisional Accretion of island arc terranes to form metamorphic basement.

1,000 - 360 m.y. ago

Later Proterozoic - Devonian

East-west extention and development of passive continental margin.

360 -250 m.y. ago

Mississippian - Permian

Development of deep marine basins.



Sevier Mountains

Sevier Mountains

Sevier Mountains


250 - 100 m.y. ago

Triassic - Jurassic

Subduction Zone

Subsidence near the front of an eastward advancing fold and thrust zone associated with Nevadan Orogeny.

100 - 66 m.y ago

East-west shortening by folding and thrusting of sedi-mentary cover over metamorphic basement above an east dipping subduction zone. Subsidence and foreland basin development from load of fold and thrust zone.

66 - 37 m.y ago

Crustal thickening and uplift by east-west shortening of basement and magmatism above a shallow, east-dipping subduction zone.



Wasatch Fault

Wasatch Fault


37 - 15 m.y ago

Magmatism (intrusion and explosive volcanism) and east-west extension above an east-dipping subduction zone.

15 m.y. ago to present

Late Miocene - Holocene

East-west Basin and Range extension, volcanism and the formation of Lake Bonneville.

(Illustration produced by Lehi Hintze, modified by Ron Harris, Wing Sze Carol Ng, Hendro Nugroho and Bill Harris)