Name: __________________ Date: _________________#___
Science
Weathering, Erosion, Soils, and Fossils
Study Guide
Test is on Friday!
Vocabulary:
Bedrock- unweathered rock that lies
below the lowest layer of soil.
Humus- the decayed remains of
plants and animals.
Delta- a large mass of deposited
sediment at the mouth of a river
Paleontologist- a scientist who
studies fossils and organisms that
lived long ago.
Deposition- the dropping off of
sediment by wind, water, ice, or
gravity.
Erosion- the movement of weathered
rock material from one place to
another.
Fossil- the preserved remains of a
plant or animal (rock).
Glacier-a large mass of slow-moving
ice that flows down a slope.
Soil- the loose material that covers
much of Earth’s surface.
Subsoil- the layer of soil just below
the uppermost layer of soil.
Topsoil- the uppermost layer of soil
(contains the most humus).
Weathering- the slow breaking apart
or wearing away of rock into smaller
pieces.
Weathering
Erosion
It’s the breaking down of rocks!
It’s the movement of weathered rocks!
What causes weathering?
What helps in erosion?
Water, wind, ice, and roots
Water, wind, ice-glaciers
Where does it all go?
The sediments get deposited at another place- Deposition!
Deltas are formed by this. The Mississippi River Delta is the largest in the US.
Soil
What is soil? What is in soil? Are there different types of soil?
Soil is made of bits of rock (sand), minerals, and material of once living things.
Humus- made of dead plants and animals (don’t get this confused with fossils!).
This is the fertile stuff that plants love! It is dark brown.
Types of Soils:
Clay- small particles, they pack together tightly. When wet, it’s sticky and
smooth with a plastic feeling.
Sand- coarse particles (grains), gritty, water flows through this material very
easily.
Silt- soft and smooth. It is made up of smaller particles of sand.
Loam- partly sticky and smooth. The darker the color, the more humus it
contains.
(Don’t forget to study the soil layers!)
Fossils
Fossils are found in rocks.
Fossils help learn about the past. They give clues about the environment of that
time period.
Types of Fossils
Molds
Casts
Petrified fossils
Amber
Loam is a type of dirt.
Farmers often use
it to grow crops