Download Earth Science EOG Review

Science EOG
Day Four: Earth Science
Geologic Evolution
Who was Alfred Wegener
Define: Pangea
What is Continental Drift?
Geologist who proposed
continental drift & pangea
Super continent or large
landmass once connected
The process by which
continent gradually split
apart from one large
landmass
The Theory of Plate Tectonics
Define: Tectonic Plates
Define: Lithosphere
Define: Asthenosphere
Large pieces of continental
or ocean crust
The uppermost layer of
Earth made of crust &
mantle
The soft layer of mantle
The layer on which the
lithosphere rests
Explain the Theory of Plate Tectonics geologic evolution
A theory that states that Earth’s lithosphere is broken into tectonic
plates that move and change position over time
Plate Boundaries: Plate boundaries are the places were two tectonic plates meet.
Movement of Plate Boundaries
Boundary
What happens
Convergent
Plates push toward each other
Divergent
Plate move pull away from each other
Transform
Plates slide past each other
Use arrows to show the
direction
Plate movements and changes on Earth’s surface
Subduction: two oceanic plates push one is pushed under the other
What happens?
Formation?
Oceanic Plate to
Continental Plate
Ocean plate sinks under
continental
Volcanic mountains
Two continental
plate collision
Buckle and push upward
mountains
A.Earthquakes & Volcanoes
Plate movements cause most changes in the Earth’s surface.
Earthquakes and volcanoes can also cause sudden changes in the Earths surface.
Definition
Type of Plate Movement
Volcanoes
Opening of the Earth's crust through
which magma is released
Convergent
Subduction
Earthquake
The shaking of the Earth’s surface
releasing stored energy from the
pressure of rocks
Transform
Hot Spots
An area of volcanic activity in the
middle of a plate
**most volcanoes and earthquakes occur in the outer rim of the Pacific Ocean.
This area is called the Ring of Fire**
A.Erosion
**the earth’s surface can also be changed slowly by the forces of erosion**
Weathering is a force that also shapes the Earth’s surface
Weathering (erosion)
Process in which
rocks are broken
down into smaller
pieces through the
action of wind, water,
roots, and animals
Mechanical weathering
Chemical weathering
Breaks rocks apart
without chemical
changes
Wears away land and
changes rock chemically
Examples:
wind
Water
Plant roots
Animals burrowing
Examples:
Air
Water
Salts
acids
Geologic Time:
The geologic time scale is like a calendar that begins with the formation of the Earth.
It is divided into 4 different categories. Define each: eon, era, period, epoch
Eon
Largest division of
time
Era
2nd largest unit of
geologic time
Mass extinctions
mark the
boundaries
Period
Smaller units that
divide eras
Epoch
Smallest unit of
geologic time
Rock formations
mark the
boundaries
Which is the oldest and largest geologic period? Precambrian
What were some of the first organisms on Earth? unicellular organisms
Unicellular – multicellular – early life forms – fish – insects – amphibians
Reptiles – mammals/dinosaurs – birds – flowers – Mammals - humans
Fossils: imprints or remains or organisms that were once alive
On what type of rock do fossils form? sedimentary
Why? Igneous rock would destroy fossils
Fossil formation: layers of sediment build up over dead organisms.
Time and pressure turn them into rock
Other ways that fossils form
Petrified
Molds and casts Carbon films
Trace fossils
Minerals enter
Openings in
plants,
Bones or
shells
Mold –
impressions in
rock (cake
pan)
Evidence of
animals
presence
Footprints,
trails, holes,
feces
Cast – shape
of the fossil
Visible layers
an image
Preserved in
tar, amber, ice
Preserve
original
remains
(actual body
parts of
organisms)
Determine the Age of Rocks
Absolute Age:
the actual age of a rock or fossil or
how long ago an event occurred
Radioactive Dating:
Measuring the age of a material
using the amount of radioactive
form of an element in a rock or
fossil

Relative Age:
Describes the age of an object or
event compared to another
object or event

What is the benefit of absolute
age?
Gives the most precise
measurement (when possible)


Law of Superposition:
In undisturbed sedimentary layers,
older layers or rock are at
bottom and become younger as
you go up

Unconformity:
A missing layer of rock due to
erosion
Fossils are Clues to the Past
List 4 ways fossils can help us learn about animals that are extinct?
1. Show how species have changed over time
2. How different species related to one another
3. Provide data about sizes, shape, growth
4. Clues about climate
Index Fossils:
fossil of an organism that existed for only a short period of time
Helpful in determining age of rock layers (relative dating)
Ice Core: vertical or tubular columns of ice
Name the two ways that ice core help us learn about Earth’s history?
Understand how climate has changed over time
Concentration of atmospheric gases
Extinction
Define: extinction:
species disappears from Earth
“Extinction occurs naturally but sometimes major events cause rapid or sudden
extinction”
List 8 natural events that can cause extinction of species:
temperature change
Volcanoes
Earthquakes
Floods/droughts
Land change
Disease
Starvation
rainfall
Describe each human threat to extinction listed below:
Habitat
Destruction
Loss of species
due to loss of
homes or rapid
change in
habitat
Pollution
Overfishing
Climate Change
Contaminated
air, water, soil,
food
Catching large
numbers and
not allowing
fish to
reproduce
Ozone
depletion,
greenhouse
gases,
Pollution affect
climate disrupt
natural cycles
This are only a few examples, if you are presented with different
examples use your knowledge and common sense
Evolution Theories
Evolution: process of change over time
Charles Darwin
Jean Pierre Lamark
Evolution theory: ACCEPTED
Evolution theory:
Proposed theory of NATURAL
SELECTION
Proposed that species acquire traits
that are passed on from parents
Explain it: Natural Selection: IMPORTANT
THEORY THAT EXPLAINS THAT SPECIES BEST SUITED FOR
THEIR ENVIRONMENT WILL SURVIVE TO REPRODUCE
Theory explains how populations respond to changes in their
environments
Why are variations important to populations?
Can lead to new species