The Continental Drift Theory, The Seafloor Spreading Theory and The Plate Tectonics Theory are the three important theories taking place in our planet.

1. By Prof. Liwayway Memije-Cruz
Plate Tectonics

2. The Continental Drift Theory
According to Alfred Wegener had once been joined together
forming a single supercontinent landmass called Pangaea that
divided into individual continents as they are now.

4. The Seafloor Spreading Theory
This theory states
that the oceanfloor
are spreading
outward from vast
underwater ridges.
This was proposed
by an American
geologist named
Harry H. Hess in
early 1960’s.

5. Seafloor Spreading

6. What is Plate Tectonics Theory?
Plate tectonics is the theory that the outer rigid layer of
the earth (the lithosphere) is divided into a couple of
dozen "plates" that move around across the earth's surface
relative to each other, like slabs of ice on a lake.

7. TYPES OF PLATE BOUNDARY
Divergent boundary or divergent plate boundary
(also known as a constructive boundary or an
extensional boundary) is a linear feature that exists
between two tectonic plates that are moving away
from each other.

8. Convergent boundary, also known as a destructive
plate boundary (because of subduction), is an actively
deforming region where two (or more) tectonic plates
or fragments of the lithosphere move toward one
another and collide.

9. Transform boundary (or conservative boundary) is where
two of the tectonic plates slide alongside each other. When
this happens, the scraping of the two plates causes
earthquakes. And since these faults neither create nor destroy
lithosphere, is a type of fault whose relative motion is
predominantly horizontal in either sinistral or dextral
direction.

10. Transform boundary (or conservative boundary) is where
two of the tectonic plates slide alongside each other. When
this happens, the scraping of the two plates causes
earthquakes. And since these faults neither create nor destroy
lithosphere, is a type of fault whose relative motion is
predominantly horizontal in either sinistral or dextral
direction.