Download The compaction and cementation of rock particles

The compaction and cementation of rock particles forms sedimentary rocks.
Sedimentary Rocks are formed at or near the Earths surface.
75% of crust is covered by sedimentary rocks, yet only 10% of the crust
is sedimentary.
Lithification – cementing particles together
involves 2 processes:
1) compaction
2) cementation
a)
b)
c)
d)
e)
Lime or calcite (bubbles in acid)
Hematite (rust or iron oxide) – Red Rocks
Limonite – yellow brown color
Silica – quartz, hardest of all cements
Clay – generally, a powder look
3 Types of Sedimentary Rocks
1) Clastic – made from the lithification of rock fragments.
2) Chemical precipitate – from chemicals that form out of solutions
3) Organic
A) Clastic – Names are based on particle size.
1) Conglomerate – 50% or more gravel size particles.
2) Sandstone – sand sized particles of quartz
3) Arkose – sandstone made up of primarily feldspar
4) Siltstone – particles you can’t see with a naked eye.
5) Shale – made up of clay, splits into layers, smells earthy when wet.
B) Chemical Precipitates – these form when
1) water evaporates, leaving the dissolved material as a sedimentary rock.
2) Small organisms with shells die, and their shells and other hard parts
accumulate to form rocks.
These rocks are named based on their mineral composition.
1) Limestone – made up primarily of calcite, and may contain fossils.
2) Coquina – loosely cemented shell fragments made up of calcite.
3) Travertine – calcite deposited around hot springs, usually layered in appearance.
4) Chalcedony – from the precipitation of quartz. Very hard rocks!
Varieties of chalcedony:
agate – banded
petrified wood
chert – light colored
flint – dark colored
5) Halite – evaporated saltwater deposit
6) Gypsum
These two rocks make up the
“evaporites”, and their mineral
name is also their rock name.
of
Coquina
Coal