EARTH SCIENCE 11 - History of Earth

1ST SEM

Petrology

Study of rocks

Stratigraphy

Study of rock layers

Paleontology

Study of fossils

Radioactive decay

This is the disintegration of the nucleus of an atom

Planetary differentiation

This is the process early in the life of each planet whereby denser elements sank inward and lighter ones stay on the surface

Relative dating

This is the process of finding the sequence of events that happened in the past

Stratified rocks

Rocks formed in layers over time

Sedimentary rocks

This is the kind of rock that shows the events that happened in the past

Principle of original horizontality

The principle where sediments are arranged with gravity, over time becomes horizontal

Principle of superposition

The principle that states the layer at the bottom is the oldest and the higher levels are younger

Principle of cross-cutting relationship

The principle where the geologic features is younger than the rocks they cut across

Principle of inclusion

The principle where rocks or fragments is included within another rock layer

Unconformity

Gaps in the deposition of rocks

Angular unconformity

The unconformity where the rocks below are tilted and the rocks above are parallel/horizontal

Disconformity

The unconformity where the layers above and below are parallel

Nonconformity

The unconformity where intrusive igneous or metamorphic rocks are below and parallel/horizontal sedimentary rocks above

Absolute/radiometric dating

Aka calendar dating which is the process that gives the numeric date when an event occurred

Half-life

It is the time for the nucleus of the atom of a radioactive element to disintegrate

Isotopes

This is where the same elements have the same no. of protons but different no. of neutrons

Carbon-14

It is the isotope used to measure the age of prehistoric plants and animals

Index fossil

It is a fossil that can show the time span of widespread ancient life forms and is a marker/guide/reference

No. of half-life x half-life

Half-life formula