GEOL 1300 Self Quiz #15

massive natural clams have formed in the gran canyon, causing the colorado river to swell into big lakes, what caused the dams?

lava flows

the "basement rocks" of the grand canyon are igneous and ______________ rocks

metamorphic

what type of unconformity is the "Great Unconformity" in the Grand Canyon?

nonconformity

the grand canyon is in _____________

Arizona

the "great unconformity" of the grand canyon represents at least _________ of missing time

a billion years

how long did it take for the Colorado River to carve out the Grand Canyon

about 6 million years

most of the sedimentary rocks above the grand unconformity were deposited ______________

by marine waters

what rock unit from the grand canyon was deposited in a desert, unlike the most other rocks in the canyon walls

coconino sandstone

T/F: dinosaur fossils are found in the sedimentary rock layer sitting on top of the "great unconformity"

false

the rocks above the great unconformity are ___________ in age, but the rocks below the unconformity are precambrian in age

paleozoic

in the grand canyon, shales tend to form _______________ on the walls of the canyon

sloping surfaces

what sedimentary bed lies immediately on the top of the "great uncomformity"?

tapeats sandstone

who was John Wesley Powell

the first geologist to study the canyon and boat through the canyon

T/F: volcanoes have been erupting on the edges of the Grand Canyon off and on for 2 million years

true