6. SSeeddiimmeennttaarryy RRoocckkss
Sedimentary rock is formed by erosion
Sediments are moved from
one place to another
Sediments are deposited in
layers, with the older ones
on the bottom
The layers become compacted
and cemented together
http://www.fi.edu/fellows/payton/rocks/create/sediment.htm
8. MMeettaammoorrpphhiicc RRoocckk
Meaning to change shape
Changes with temperature
and pressure, but remains
solid
Usually takes place deep in
the Earth
http://www.fi.edu/fellows/payton/rocks/create/metamorph.htm
36. OOtthheerr ttyyppeess ooff UUnnccoonnffoorrmmiittiieess
Faulting- Movement
of the Earth’s plates
causes rock to crack
and shift.
Intrusion- Magma from
the Earth’s mantle moves
into the rock layers, cools
and hardens. (Igneous
Rock)
37. Other types ooff UUnnccoonnffoorrmmiitteess ((ccoonntt..)
Folding- Earth’s plates are
pressing together. This
movement causes them to
bend and fold. This
process forms mountains.
Erosion- described
earlier. Layers of rock are
washed away and new
rock built on top. Leaves
gaps in geologic record.
53. AAbbssoolluuttee DDaattiinngg ooff rroocckkss
AAbbssoolluuttee DDaattiinngg//RRaaddiiooaaccttiivvee DDeeccaayy
iiss wwhheenn sscciieennttiissttss uussee rraaddiiooaaccttiivvee
ddaattiinngg ttoo ddeetteerrmmiinnee tthhee aabbssoolluuttee aaggeess
ooff rroocckkss..
–Radioactive decay-over
time certain elements break
down, or decay, by releasing
particles and energy.
–Half life- The constant rate
of decay of an element.
(Carbon 14 has a half-life of
5,730 years)