Earth Science CET (Plate Boundaries and Geological Time Scales, and Rocks)

They interact at locations called plate boundaries,

found at the edge of the lithospheric plates.

Tectonic plates

This is a type of boundary where two

plates meet and push one another.

Convergent boundary

When the crust is destroyed, the denser plate sinks in a

process called?

Subduction

It is is a process of pulling something down.

Subduction

Types of Convergent Boundaries:

1. Continental-continental convergent boundaries

2. Oceanic-continental convergent boundaries

3. Oceanic-oceanic convergent boundaries

It is a geologic process that occurs at mid-

ocean ridges, where new oceanic crust is formed through

volcanic activity and then gradually moves away from the ridge.

Seafloor spreading

One oceanic plate subducts another oceanic plate.

Forms mountains, earthquakes, volcanic islands and

trenches when plates collide.

Oceanic-Oceanic Convergent Boundaries

When one plate is oceanic and the other is continental,

the denser oceanic plate is subducted, forming an

orogenic belt and associated mountain range.

Volcanic arc is a chain of volcanoes formed above a

subducting plate.

Oceanic-Continental Convergent Boundaries

It is when a subduction zone is

destroyed, mountains produced, and two continents

sutured together.

Continental-Continental Convergent Boundaries

Continental collision

Examples of Convergent Boundaries:

1. Mount Fuji, Japan

2. Mount Lassen, California

3. Himalayan Mountains

4. Andes, South America

Regions where a plate moves away from each

other/comes apart.

Most are found deep in the ocean

floor, hence separation of plate is also called “sea floor

spreading.”

Rift valleys and ocean ridges form at these boundaries.

Divergent boundaries

Oceanic plates are composed of mafic or basaltic rock.

When oceanic plates separate, brand new crust is created.

This crust can remain underwater creating ridges, or can

rise to the surface creating islands.

Oceanic Plate Divergent Boundary

This is an underwater mountain system formed by plate

tectonics.

Mid-Ocean Ridge

When continental plates separate, volcanoes could form to

create new crust.

Continental Plate Divergent Boundary

A linear-shaped lowland between several highlands

created by the action of a geologic rift or fault.

Rift Valley

Examples of Divergent Boundaries:

1. East Asian Rift

2. Mid-Atlantic Ocean Ridge

Places where plates slide sideways past each other.

The fracture zone that forms a transform boundary is known

as a transform fault.

Transform Boundaries

Examples of Transform Boundaries:

1. Calexico, California

2. San Andreas Fault

Types of Eon:

1. Hadean Eon (4.6 to 4 billion years ago)

2. Archean Eon (4 to 2.5 billion years ago)

3. Proterozoic Eon (2.5 billion to 541 million years ago)

4. Phanerozoic Eon (541 million years ago to present)

The Earth forms from the solar nebula.

The Moon is believed to have formed as a result of a

collision between the early Earth and a Mars-sized body,

named Theia.

Hadean Eon (4.6 to 4 billion years ago)

The earliest known life forms, simple single-celled organisms

(prokaryotes), appear.

The Earth's crust cools enough to form continents.

Archean Eon (4 to 2.5 billion years ago)

Cyanobacteria produce oxygen through photosynthesis,

leading to the Great Oxidation Event.

Complex cells with a nucleus (eukaryotes) appear.

Severe glaciations occur, potentially covering the Earth in

ice.

Proterozoic Eon (2.5 billion to 541 million years ago)

Rapid diversification of life forms, including many major

groups of animals.

Plants colonize land, leading to significant changes in Earth's

atmosphere and ecosystems.

Phanerozoic Eon (541 million years ago to present)

This is a term that refers to the rapid

emergence of complex life forms in the Cambrian Period,

about 541 million years ago. It was characterized by the

appearance of many of the major animal phyla that make up

modern animal life.

Cambrian explosion

Eras within the Phanerozoic Eon:

1. Paleozoic Era (541 to 252 million years ago)

2. Mesozoic Era (252 to 66 million years ago)

3. Cenozoic Era (66 million years ago to present)

The Cambrian Explosion, a major

diversification of life, occurs.

Cambrian Period

Marine life flourishes, and the first

vertebrates appear.

Ordovician Period

The first vascular plants appear on land.

Silurian Period

Known as the "Age of Fishes," the first

amphibians appear.

Devonian Period

Extensive forests of vascular plants

form, leading to large coal deposits; first reptiles appear.

Carboniferous Period

Ends with the largest mass extinction in

Earth's history, the Permian-Triassic extinction event.

Permian Period

Dinosaurs and mammals first appear.

Triassic Period

Dinosaurs dominate the land; the first birds

appear.

Jurassic Period

Flowering plants appear; ends with the

Cretaceous-Paleogene extinction event, which wipes out the

non-avian dinosaurs.

Cretaceous Period

Mammals diversify and become the

dominant land animals.

Paleogene Period

Further diversification of mammals and

birds; hominins (early human ancestors) appear.

Neogene Period

Includes the Pleistocene and Holocene

epochs; characterized by repeated glacial cycles; modern

humans (Homo sapiens) appear and develop civilization.

Quaternary Period

It was a supercontinent that existed during the late

Paleozoic and early Mesozoic eras. It assembled from

earlier continental units approximately 335 million years

ago and began to break apart about 175 million years ago.

Pangaea

Pangaea formed through the _________ of

smaller landmasses and continents over millions of years.

This process began in the late Carboniferous period

(around 335 million years ago) and continued into the

early Permian period.

Collision and amalgamation

Pangaea was surrounded by a vast global ocean called

________ and included a smaller inland sea known as

_____.

Panthalassa
Tethys

The breakup of Pangaea began in the early Jurassic period

(about 175 million years ago) due to?

Rifting and the

movement of tectonic plates.

Pangaea initially split into two smaller supercontinents:

1. Laurasia in the northern hemisphere

2. Gondwana in the southern hemisphere

Over millions of years, Laurasia and Gondwana continued

to break apart into the continents we recognize today, which are:

Laurasia:

1. North America, Europe, and Asia

Gonwana:

1. South America, Africa, Antartica, India, and Australia

Types of Rocks:

1. Igneous Rocks

2. Sedimentary Rocks

Formed from the cooling and solidification of molten rock

(magma or lava).

Igneous Rocks

Igneous Rocks can range from?

Coarse-grained (intrusive) to Fine-grained (extrusive)

Igneous Rocks are typically composed of minerals such as:

1. Quartz

2. Feldspar

3. Mica

4. Olivine

5. Fluorite is much less common to find in igneous rocks.

The higher the silica, the ______ is the rock, while the

faster the rate of ______, the finer the crystals.

Lighter

Crystallization

Formed from magma that

cools slowly beneath the Earth's surface. Examples include

granite, diorite, and gabbro;

Intrusive (Plutonic):

Formed

from lava that cools quickly on the Earth's surface.

Examples include basalt, obsidian, rhyolite, and andesite.

Extrusive (Volcanic):

Formed from the accumulation and compaction of

sediments or by the precipitation of minerals from water.

Often show distinct layers or strata.

May contain fossils, which are remains of ancient

organisms

Sedimentary Rocks

Types of Sedimentary Rocks:

1. Clastic

2. Chemical

3. Organic

Formed from fragments of other rocks that

have been weathered, transported, and deposited.

Example: Sandstone.

Clastic

Formed from the precipitation of minerals

from water. Example: Limestone.

Chemical

Formed from the accumulation of plant or

animal debris. Example: Coal.

Organic

Formed from the alteration of existing rock types (igneous,

sedimentary, or other metamorphic rocks) through heat,

pressure, and/or chemically active fluids.

Can range from fine-grained to coarse-grained.

New minerals may form under high pressure and

temperature conditions.

Metamorphic Rocks

Types of Metamorphic Rocks

1. Foliated

2. Non-foliated

Have a layered or banded appearance due to

the alignment of minerals. Example: Schist.

Foliated

Do not have a layered appearance.

Example: Marble

Non-foliated