In this bottom section of the rock layers in the Grand Canyon, the oldest rock is shown in these angled layers. Explain what happened in terms of plate tectonics and other conditions to create this section (from the Vishnu Schist, Zoroaster Granite, Igneous intrusion, Bass Limestone, Hakatar Shale and the Shinumo Quartzite)

Explanation:Igneous rocks

are formed

when rock is

super-heated and

becomes molten

(liquid). There are two kinds of

molten rock: magma (found

beneath the Earth’s surface) and

lava (found on the Earth’s

surface). The molten rock cools

and hardens on or beneath the

Earth’s surface forming a variety

of igneous rock. Two examples

are granite and basalt.

Layers in Time: Geology of Grand Canyon

How did Grand Canyon form? By studying geology we

learn about the Earth’s history and how places change over time.

What plants or animals lived in your town 150 million years ago?

The ancient remains of plants and animals preserved in the rock,

called fossils, tell stories about the past. Take a look at the chart of

common fossils at Grand Canyon on the back page.

Vocabulary:

Fossils: the hardened

remains or imprints of plants

or animals preserved in rock

Geology: the study of the

origin, history and structure

of the earth

THE OLDEST PANCAKE IN A

STACK IS ALWAYS AT THE

BOTTOM. THE ROCKS AT

GRAND CANYON ARE A LOT

LIKE PANCAKES. WHERE

DO YOU FIND THE OLDEST

ROCKS AT GRAND CANYON?

Think About It

Sedimentary rocks are made

of smaller pieces (like sand or

mud), called sediments, that

pile into layers. As pressure

on the sediment increases over

time, minerals act like glue,

cementing them into solid

rock. The three main types of

sedimentary rocks at

Grand Canyon

are sandstone,

shale (or

mudstone),

and limestone.

Metamorphic rocks are

rocks that

have been

changed

under

great heat

and pressure. The original

rock can be sedimentary,

igneous, or even metamorphic.

The original rock is changed

into something new, just as a

caterpillar “metamorphoses”

into a butterfly

answer; self-efficacy;