where was the material that was eroded by the colorado river deposited
Regions in the Mesozoic and Cenozoic
Geology of the Grand Canyon area
region in the Mesozoic and Cenozoic 
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Geology of the Grand Canyon area [SEP] Mesozoic deposition
Formations totaling over in thickness were deposited in the region in the Mesozoic and Cenozoic but were almost entirely removed from the Grand Canyon sequence by subsequent erosion. The geology of the Zion and Kolob canyons area and the geology of the Bryce Canyon area records some of these formations. All these rock units together form a super sequence of rock known as the Grand Staircase.