UTAH’S GEOLOGIC HISTORY
P R E H I S T O R I C L AN D AN D AN I M AL S
UTAH’S GEOLOGIC HISTORY
• Geologists are scientists who study
the earth such as rocks and land
forms. From studying rocks,
geologists have divided the earth
into major division of times called
Eras. The earliest know geologic
era is call the Precambrian Era.
UTAH’S GEOLOGIC HISTORY
• The Mesozoic Era is associated
with dinosaurs which roamed Utah
and many other places. Dinosaur
bones have been found in Jensen,
Vernal, and Price. In 1992, a
newly discovered dinosaur with
huge slashing claws was called
the Utahraptor.
UTAH’S GEOLOGIC HISTORY
• Write down some of the other
dinosaurs that were found in Utah:
Brontosaurus, Allosaurus,
Tyrannosaurus, Stegosaurus,
Camptosaurus, Camarasaurus,
Diplodocus.
UTAH’S GEOLOGIC HISTORY
• Sediment, or loose sands, shells,
and pebbles drift to the bottom of
the seas. With heat and pressure,
the sediments were turned into a
hard rock. Fossils were formed
from dead plants and animals.
UTAH’S GEOLOGIC HISTORY
• Utah’s limestone and dolomite is
made of shells of ancient sea
animals. Mountains were formed
(a) by the pressure from ocean
floors, (b) flat areas rising up in
huge folds, and (c) cracks causing
some places to slip down.
UTAH’S GEOLOGIC HISTORY
• The Rocky Mountains were formed
by pressure form surrounding
landforms. As part of the uplift,
faults—a crack in the Earth’s crust,
began to form at weak spots in
the Earth’s crust. Pressure inside
the Earth pushes up lava to form
volcanoes.
UTAH’S GEOLOGIC HISTORY
• Water coming to the Earth’s
surface forms geysers and hot
springs. Utah is rich in fossil fuels
such as oil, coal, and natural gas.
Utah’s minerals come from the
bodies of many plants and
animals, combine with heat and
pressure.
TOP OF THE BACK PAGE
• During the Ice Age, the
temperatures were cooler than
today around 15 degrees on
average. It caused huge sheets of
ice called glaciers to cover the
Utah mountains. Utah’s canyons
were created by glaciers moving
downward from the mountains.
UTAH’S GEOLOGIC HISTORY
• Some animals such as the
mammoth were a huge Ice Age
animal. Just like the dinosaurs, a
mammoth skeleton was
discovered near Huntington
Reservoir.
UTAH’S GEOLOGIC HISTORY
• Write down some of the Ice Age
animals that were discovered:
Mammoth, Bison, Giant Camel,
Sabor-Tooth Tiger, Sloth, Musk, Ox,
Cave Bears.
UTAH’S GEOLOGIC HISTORY
• As temperatures warmed up
during the Ice Age, glaciers
malted and the water level rose
and one lake covered much of
Utah in the ancient times: Lake
Bonneville. One remnant of Lake
Bonneville is the Great Salt Lake,
Utah’s largest body of water.
UTAH’S GEOLOGIC HISTORY
• The Great Salt Lake has enough
salt to satisfy the world’s needs for
a thousand years. Three thing to
know about the GSL: (a) no water
flows out of it (b) It was once part
of an ancient lake (c) It is the
largest salt water lake in the
western hemisphere.
UTAH’S GEOLOGIC HISTORY
• Today Utah’s land has not stopped
changing and will never stop
changing. Wind, water, ice, heat,
cold, floods, and earthquakes can still
bring about change. Utah has over
700 small earthquakes and about
one large earthquake a year.
THE END
C H AP T E R 2 T E S T WI L L B E N E X T WE E K