Zion National Park Geology

In a magnitude 5. This is a result of minimal iron-oxide compared to other layers of sandstone. Three houses and two water tanks were destroyed when the slope they were built on dropped 98 feet 30 m and extended laterally a similar distance over a period of several hours.

Geology of the Zion and Kolob canyons area

Within this sequence, the oldest exposed formation in the Zion and Kolob canyons area is the youngest exposed formation in the Grand Canyon —the Kaibab limestone. In fact, the youngest formation seen in the Zion and Kolob area is the oldest exposed formation in Bryce Canyon —the Dakota Sandstone. In the Permian period, the Zion and Kolob area was a relatively flat basin near sea level on the western margin of the supercontinent Pangaea. These sediments later lithified turned to rock to form the Toroweap Formationnow exposed in the Grand Canyon to the south but not in the Zion and Kolob area.

This formation is not exposed in the park, though it does Zion National Park Geology its basement rock. Deposition of sediments[ edit ] Kaibab Limestone Upper Permian [ edit ] In later Permian time, the Toroweap Basin was invaded by the warm, shallow edge of the vast Panthalassa ocean in what local geologists call the Kaibab Sea. At that time, Utah and Wyoming were near the equator on the western margin of the supercontinent Pangaea. In the park, this formation can be found Zion National Park Geology the Hurricane Cliffs above the Kolob Canyons Glacier National Park To Great Falls Mt Center and in an escarpment along Interstate 15 as it skirts the park.

Farther to the west, a complex island arc assemblage formed above a subduction zone. To the east, in western Coloradoa mountain range similar to today’s Himalayas called the Uncompahgre Mountains bordered the Utah lowland.

Shallow, marine water stretched from eastern Utah to eastern Nevada over a beveled continental shelf. As the sea withdrew around million years ago, fluvial, mudflat, sabkhaand shallow marine environments developed, depositing gypsum from lagoon evaporitesmudstoneslimestones, sandstonesshalesand siltstones. The fossilized plants and animals in the Moenkopi are evidence of a climate shift to a warm tropical setting that may have experienced monsoonalwet-dry conditions.

George area. Ripple marksmud cracksand thinly laminated bedding suggest that these intervening red shale and siltstone units were deposited in tidal flat and coastalplain environments. Progressively higher beds are exposed until the top of the formation is reached at the mouth of Parunweap Canyon when traveling to the park on Route 9.

Chinle Formation Upper Triassic [ edit ] Later, uplift exposed the Moenkopi Formation to erosion and Utah became part of a large interior basin drained by north and northwest-flowing rivers in the Upper Triassic. The purple, pink, blue, white, yellow, gray, and red colored Chinle also contains shale, gypsum, limestone, sandstone, and quartz.

Ironmanganese oxides and copper sulfide are often found filling gaps between pebbles. Purplish slopes made of the Chinle can be seen above the town of Rockville. The sand, graveland petrified wood which made up these deposits were later strongly cemented by dissolved silica probably from volcanic ash from the west in groundwater.

The Shinarump was laid down in braided Zion National Park Geology that flowed through valleys eroded into the underlying Moenkopi Formation.

Moenave and Kayenta formations Lower Jurassic [ edit ] Early Jurassic uplift created an unconformity above the Chinle Formation that represents about ten million years of missing sedimentation between it and the next formation, the Moenave.

Paleocurrent studies show that the Kayenta rivers flowed in a general westward to southwestward Glacier National Park To Great Falls Mt. Eventually, this created a rain shadow and brought widespread desertification. Typically the lower part of this remarkably homogeneous formation is reddish from iron oxide that percolated from the Glacier National Park To Great Falls Mt iron-rich Temple Cap formation while the upper part of the formation is a pale tan…

The Formation of Zion

Farther to the west, a complex island arc assemblage formed above a subduction zone. Tectonic activity and erosion[ edit ] Regional forces[ edit ] East—west-directed compression from subduction off the west coast affected the area in later Mesozoic and early Tertiary time by folding and thrust faulting strata. Within this sequence, the oldest exposed formation in the Zion and Kolob canyons area is the youngest exposed formation in the Grand Canyon —the Kaibab limestone. The seabed turned to limestone and mud and clay changed to mudstone and shale, forming the sweeping diagonal cross-bedding that Zion National Park is famous for.