Chapter 11

Transform Fault

---- Boundaries are the places where two plates are sliding past each other, usually without any Volcanic activity.

Orogenesis

---- is the most common type of mountain building.

Divergent

---- plate boundaries are found where two plates are moving away from each other.

Convergent

A ---- Boundary is where two plates collide with each other.

magma

At Hot Spots, continual Plumes of ---- force its way through weaknesses of the earth's crust.

mountain ranges

During Orogeny, when two continental plates collide, the edges buckle and become ----.

Rifting

During Sea Floor Spreading, when a continental plate begins to splits apart is called ----.

Minnesota

Hundreds of millions of years ago, a Mid-continental Rift zone was actually centered on ----, and North America almost split into two as a result. After splitting between 25 and 100 miles apart, however, this rifting stopped. Part of it can still be seen, and is occupied today by Lake Superior!

Isostatic Depression

If there is a lot of "weight" (such as mountains or continental glaciers on the crust), then the crust will sink lower into the upper mantle. This is called ----.

Isostatic Rebound

If weight is taken off of the crust (through the erosion of mountains or the melting of glaciers), then the crust will rise higher from the upper mantle. This is known as ----.

Nevada

North America today has a rift zone, centered on ----.

more

Oceanic Crust is ---- dense than Continental Crust.

Less

Oceanic Crust is ---- thick than Continental Crust.

continental, oceanic

One Tectonic Plate can contain just ---- crust, just ---- crust, or both.

friction, radioactive

Parts of the Asthenosphere are molten due to ---- and the decay of ---- minerals.

Hot Spots

Places on the earth away from plate boundaries, where volcanism occurs.

Tectonic Plates

Sections of the crust, whether continental or oceanic, are broken into pieces called ----.

Moho

Slang for the Mohorovicic Discontinuity is ----.

Rift Valley

The ---- Lakes (Lakes Albert, Malawi, Kivu, Tanganyika, and Edwards are a few) occupy areas where the Earths crust has begun to split.

Hawaiian Islands

The ---- are perhaps the most famous example of Hot Spots.

Lithosphere

The Asthenosphere moves about the Earth's surface, carrying the ---- (and us!) along with it.

Mantle

The Earth's ---- runs from Earth's core to the Earths crust.

Iron

The Earth's Core is mostly ---- in Composition. fluid generates electricity, producing earth's magnetic field.

Isostasy

The Earth's Crust floats or balances on top of the upper mantle. This "floating" is called ----.

Plate Tectonic Theory

The Tectonic plates move slowly about the earth's surface, jostling, colliding, and even overrunning each other. This process is referred to as ----. The Earths surface is continually being reformed in the process.

solid

The Upper Mantle is mostly in a ---- state.

Lithosphere

The Upper Mantle, along with the earth's crust form the ----.

East African Rift Zone

The best example today, of Rifting, is the ----, where part of East Africa is beginning to split off from the rest of the continent.

Mohorovicic Discontinuity

The boundary between the Lithosphere and the Asthenosphere is called the ----, named for the Yugoslavian geologist who first identified its existence.

crust

The earth's ---- rides on top of the Upper Mantle.

Thickness, Density, Composition

The earth's crustal types vary in ----, ----, and ----.

solid, pressure

The inner core is ----, because of the intense gravitational ---- from the rocks above it.

Asthenosphere

The layer beneath the Lithosphere is a plastic, semi or partly molten layer called the ----.

Ridges, valleys

The magma rising to fill the void between two diverging plates does not flow evenly, but in fits and spurts. The spurts form Mid-Oceanic ----, while oceanic ---- form between them.

Granite

The main composition of Continental Crust is ----.

Basalt

The main composition of Oceanic Crust is ----.

Magma, Lava

The molten part of the Asthenosphere can rise into the crust as ---- (beneath the surface), or ---- (if it breaks through to the surface).

Pacific

The most famous example of a Transform Fault Boundary is the San Andreas Fault, where the North American plate and the ---- Plate are sliding past one another.

magnetic field

The outer core is fluid, and the convective movement of this iron fluid generates electricity, producing earth's ----.

Sea-floor Spreading

The process when two oceanic plates are diverging, magma rises from below to fill the void and create new oceanic crust.

Upper Mantle

The top layer of the Mantle is called the ----.

Oceanic, Continental

There are Two types of crust, ----, and ----.

20, between

There are at least ---- main tectonic plates on the Earth's Surface, with even smaller pieces of crust being ground ---- them.

Oceanic

When Oceanic and Continental crusts collide, the ---- crust is forced downward.

Continental

When Oceanic and Continental crusts collide, the ---- crust is forced upward.

Subduction Zone

When an Oceanic crust collides with a Continental Crust, it is forced beneath the continental land mass. This is called a ----, and forms a deep valley, or Oceanic Trench.

Plate Boundaries

Where plate edges meet each other.

Basalt

a common extrusive igneous (volcanic) rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon.

Granite

an intrusive igneous rock that has many uses in building construction and architectural design.