THE EARTH!
EARTH’S LAYERS
Crust: the rigid rocky outer layer; 23.5 miles thick
Mantle: Rocky layer containing magma; thickest layer under the crust; Made of
metals; 1775 miles thick; Temperature ranges from 1600-6700 degrees
Convection: Circular movement where hot air or magma rises and the cooler air
sinks causing a circular pattern. Causes the plates to move.
Outer Core: Made of molten iron-nickel; surrounds the inner core; 1420 miles
thick. Liquid. 6700-8000 degrees.
Inner Core: Center of the earth; solid iron-nickel; very hot and under; great
pressure. 767.5 miles thick; 13,000 degrees
SPHERE WORDS:
Geosphere: the solid rocky surface and the inside of the planet.
Hydrosphere: earth’s water in seas and on land.
Atmosphere: the air that surrounds earth.
Biosphere: all living things on earth!
Lithosphere: A layer that combines the crust and the upper mantle.
ROCK CYCLE
SEDIMENTARY
FORMS:
*From sediments compacting and cementing together.
CHANGES:
*under weathering and erosion turns into sediments. into metamorphic rocks
under heat and pressure
Examples of SEDIMENTARY ROCKS: shale, limestone, sandstone
IGNEOUS
FORMS:
*from cooling magma
CHANGES:
*under heat and pressure turns into metamorphic rocks;
*under weathering and erosion turns into sediments.
*can melt.
Examples of IGNEOUS ROCKS: granite, pumice, obsidian, basalt
METAMORPHIC
FORMS:
*under heat and pressure
CHANGES:
*can melt and turn into magma
*under weathering and erosion turns into sediments.
*into Igneous rocks when magma cools
Examples of METAMORPHIC ROCKS: marble, slate, quartz
Weathering and Erosion
I. WEATHERING
A. PHYSICAL WEATHERING
1. DEFINITION: Breaks rocks into smaller and smaller pieces
2. Three types of Physical Weathering
a. FROST WEDGING:
b. ABRASION:
c. LIVING ORGANISMS: plant roots, animals burrowing
B. CHEMICAL WEATHERING
1. DEFINITION: Changes rocks and minerals into new chemical combinations
2. Three types of Chemical Weathering
a. SOLUTION WEATHERING:
b. OXIDATION: oxygen combines with iron and water. Example: rusty nails
c. LICHENS AND MOSSES: release acid which breaks down rocks.
II. EROSION
DEFINITION: The removal or transporting of rocks.
A. Four Types of Erosion
1. GRAVITY: causes mass movement.
2. RUNNING WATER: carries particles away and sorts them. MOST
POWERFUL
3. ICE: rocks frozen in ice contribute to physical weathering by abrasion.
Glaciers
4. WIND: particles are picked up and carried off.
III. DEPOSITION
A. Sand grains have formed due to weathering and erosion and have been
transported by wind, water, and ice.
B. The sand is then deposited in a new area and forms sedimentary rocks.
IV Other Rock Information
A. sediments settle and form a flat, horizontal layer.
B. The rock layer on the bottom is the oldest.
C. The processes we observe today have occurred this way throughout
Earth’s history.
SOIL
1. Soil is a layer of dirt between the atmosphere and the bedrock in the tectonic
plates.
2. Soil is found on the surface of the lithosphere.
3. It is made up of minerals (rock, clay, sand, silt), water, air, and organic (plants
and animals) material.
4. There are many types of soil. Each is unique by color, texture, and minerals.
5. Soil is formed slowly as rocks erode.
6. Organic matter decays and mixes with inorganic material to form soil.
7. Soil is divided into layers. They are called horizons.
8. The bottom horizon develops first.
9. Humus is rich organic material.
Water
Found on the earth: oceans, seas
Found under the earth: streams, drains
Found in the atmosphere: vapor, clouds
Ocean Water
1. Oceans cover about 70% of the earth’s surface.
2. Oceans contain roughly 97% of earth’s water supply.
3. We are the only planet with water.
4. Oceans affect the weather and temperature of earth.
5. Oceans moderate the earth’s temperature by absorbing incoming solar
radiation and stores it as heat energy.
6. Ocean currents are constantly moving and distribute heat energy around the
world.
7. All the oceans are connected to each other.
8. As water flows in rivers it picks up small amounts of mineral salts from rocks
and soil. Then it flows into the oceans and seas. Salt does not evaporate like
water, which is why the ocean water gets salty.
Fresh Water
Fresh water is located in streams, lakes, and rivers.
Reservoirs store water for future use.
Estuaries are where fresh water and salt water mix.
Geological Timeline
1. EON: the largest division of time.
2. ERA: broad span of time based on the life that existed. “Zoic” refers to animal
life.
3. PERIOD: shorter spans of time—based on earth’s crust and rock formation.
4. EPOCH: based on layers of rock. Names are based on the % of fossils in the
rocks represented by animals and plants living today.
FOSSILS: Any remains, trace or imprint of a plant or animal that has been
preserved in the earth.
Index FOSSILS: A fossil found in only one layer of rock in an area. It can identify
the age of the specific rock layer it is found in.
SCIENTISTS:
Paleontologist: scientist who studies fossils.
Geologist: scientist who studies the earth…rocks scientists
Wegener: Came up with the Continental Drift Theory.
Lamarck: Defined the word Fossil.; Father of paleontology
William “Strata” Smith: Father of stratigraphy and historical geology.
James Hutton: Came up with uniformitarianism which means: “the present is the
key to the past.”