Geology,
derived from the Greek geo, "Earth," plus logos, "study,"
The study of the planet Earth
Two major divisions: physical geology and historical geology
Physical
geology: Examines the materials composing the earth and the processes that are
in operation.
Historical
geology
To
understand the origin of the earth and it’s development through time.
Mineralogy:
The study and classification of minerals.
Petrology:
Deals with the origin, structure, occurrence, and history of rocks.
Structural
geology: Has to do with the deformation of rocks and their structural attitude
or arrangements.
Geomorphology:
Deals with the origin, development, and classification of landforms.
Economic
geology: has to do with geologic processes and materials that can be utilized by
humans.
Physical
geology includes seismology: The study of earthquakes and the Earth's interior.
Volcanology:
the study of volcanoes and volcanic phenomena
Glaciology:
The study of glaciers and glaciation.
Marine
geology: or geological oceanography deals with the sea
Historical
geology includes:
Stratigraphy:
Dealing with the study, interpretation, and correlation of rock strata.
Paleontology:
The study of prehistoric plants and animals as revealed by their fossils and
related to the chronology of the Earth's history.
Alfred
Wegener (1880-1930) (1915)
Theory of continental drift: The present continents were originally one large
landmass
Plate
tectonics is closely related to structural geology
Paleogeography:
Deals with the physical geography of all or part of the Earth's surface at some
time in the geologic past.
Paleoclimatology:
The study of climates of the geologic past.
Paleoecology:
The study of the relationship between ancient organisms and their environment.
Paleomagnetism:
The study of the Earth's magnetic field over geologic time.
Micropaleontology:
The study of microscopically small fossils.
James
Ussher
(1581-1665) was the first to estimate the age of the Earth using genealogies of
the Bible. Ussher stated in 1650 that the Earth was created on October 22, 4004
BC.
Thus,
a very young Earth provided a basis for most chronologies until the 18th
century.
CATASTROPHISM
The
physical features of the earth were formed by sudden spectacular events.
Scottish
geologist James Hutton (1726-97) is the founder of modern geology.
His chief contribution was the doctrine of uniformitarianism
The
Present is the key to the past.
The
physical, chemical and biological laws that operate today also operated in the
past
The
laws were the same but the rates may have varied.
Steno’s
Principles
Principle
of Superposition
Oldest
strata are at the bottom in an undisturbed sequence of strata
Principle
of Original Horizontality
All
strata are horizontal when they form
Principle
of Original Lateral Continuity
Strata
originally are unbroken flat expanses Interrupted by erosion
Cross-cutting
Relationships
Principle
of Intrusive Relationships
Intrusive
igneous rocks are always younger than the rock they invade
Principle
of Components
Fragments
within a second body of rock are older than the second body of rock