2. OBJECTIVES:
At the end of the presentation, you
should be able to know about the
following:
• Definition of Diastrophism
• Theories explaining Diastrophism
• Stress and Strain
• Faults and Folds
3. Defining DIASTROPHISM:
Tectonism
deformation of Earth’s crust by
natural processes (movements)
leads to the formation of continents
and ocean basins, mountain
systems, plateaus, rift valleys, and
other features.
4. TRIVIA:
Do you know that?
Due to Earth’s gravity it is impossible
for mountains to be higher than
49, 000 feet (15,000 metres).
6. 1.) Isostasy Theory
state of gravitational
equilibrium between
the Earth's
lithosphere and
asthenosphere
tectonic plates "float"
at an elevation
which depends on
their thickness and
density.
11. Shrinking
resulted in a
reduction in the
Earth’s diameter
while the
circumference
remained
unchanged due
to folding and
buckling of the
crust
12. 3.) Convection Current Theory
convection
within the
Earth's mantle
pushes the
plates
movement of a
fluid, caused by
differences in
temperature
13. According to this theory:
Theplate is the cooled surface
layer of a convection current in
upper mantle.
14. 4.) Continental Drift Theory
Continents were
joined in a
super-continent,
called Pangaea
(all lands). Over
a vast period of
time, the
continents
drifted apart to
their current
locations.
24. STRESS AND STRAIN
3 main concepts about stress and strain:
rocks deform,
stress causes strain and strain results in
structures,
different physical conditions create
different structures