Wegener's hypothesis was based on the observation of

The current land masses were once all joined together in a supercontinent called

The fern-like plant fossil that Wegener found Africa, South America, Australia, India and Antarctica supporting his hypothesis was called

The hypothesis that the continents today had once been one large landmass that had separated or drifted apart is now known as

Freshwater ____________ fossils, Mesosaurus and Lystrosaurus, were found on land masses separated by vast oceans.

Fossils of tropical plants found in cold, arctic regions of today, provides evidence for

______________ are traces of ancient organisms preserved in rock.

An "educated guess" to explain an observation is called a

A hypothesis becomes a _____________ when it is supported by a body of scientific evidence.

The navy man who created the idea of sea floor spreading 50 years after the theory of continental drift was

________________ observed cracks in the continental crust and explained that the lithosphere is broken up into separate plates.

The theory of _________ states that piece's of Earth's lithosphere are in slow, constant motion, driven by convection currents in the mantle.

The following picture shows ___________ where the colder molten rock descends deeper in the Earth's mantel and hotter rock rises up toward the surface.

The edges of plates join together at

Most natural disasters, such as earthquakes occur along

_______ are breaks in Earth's crust where rocks slip past each other and form along plate boundaries.

There are ______ types of plate boundaries.

The three types of plate boundaries are

________ boundaries occur at places where two plates move apart or separate.

__________ boundaries occur where two plates come together.

When two plates collide, ______________ occurs with one plate going under the other plate.

When oceanic crust collides with continental crust, subduction occurs where

When two oceanic plates collide, the ________ dense plate will subduct under the other.

Where two oceanic crusts collide, the land formation ___________ will often be created.

___________ are made when two continental crust plates collide because neither one is dense enough to fully subduct under the other.

______ boundaries occur where two plates slip past each other, moving in opposite directions.

___________ often occur at transform boundaries.