Grade 9 / Science / Abeka / Chapter 8

The study of the earth

Earth's outer layer of rock; portion we are most familiar with

The portion of the crust underlying the continents; a rock chiefly composed of silica and alumina

The surest under the oceans; a denser rock that contains silica and significant amounts of magnesium

Deposits of sand and mineral fragments 

The most abundant element in the earth's crust; makes up 50% of the earth's crust by weight

Marks the lower boundary of the crust 

The middle layer of the earth

Marks the lower boundary of the mantle and lies roughly 2900 km beneath the surface

Central part of the earth

"float" like rafts on the plastic rock of the upper mantle 

Slow convection currents in the plastic rock of the upper mantle

One huge land mass

When a layer of rock breaks under the strain of the forces upon it and moves

Occurs when rocks along one side of a fault sink vertically

Occurs when rocks along one side of a fault move horizontally along the fault

Results when rocks on one side of a fault are thrust on top of the rocks on the other side

Formed by the bending or buckling of rocks under great force

Trough like structure

An arch like structure 

Formed when molten rock erupts from a hole in the earth's crust

Appear to be formed when molten rock is forced beneath an overflying rock layer, forcing the layer upward into a blister like dome

Thought to have been formed when the edges of two adjacent rock layers were pushed violently together, causing the layers to buckle like a wrinkled rug 

Some of the most spectacular mountains in the world 

Any trembling or shaking of the earth's crust; sudden movement of rock masses along a fault