Download Sedimentary Rocks

Sedimentary Rocks
rocks formed from the compaction
(sqeezing) and cementation of
sediments.
Sediments - pieces of solid material
that have been deposited on Earth’s
surface through weathering and
erosion.
Test Tips
• Key words for sedimentary rocks: weathering,
erosion, deposition, compaction,
cementation.
• The names of sedimentary rocks often include
the word “stone” or “rock.”
– Examples:
limestone,
sandstone,
rock salt
Sedimentary Classifications
1) Clastic – formed from deposits of loose
sediments on Earth’s surface.
- formed mostly by physical processes.
Rock Cycle Animation
Cementation animation
a) Coarse Grained – big sediments
(boulders, pebbles and gravel bigger than
2 mm)
Clastic Sedimentary Rocks
Conglomerate coarse grained, rounded
Breccia coarse grained, jagged
Clastic Sedimentary Rocks
• b) Medium Grained - made of sand less than2
mm. Example: sandstone.
- sandstone
Clastic Sedimentary Rocks
c) Fine Grained – made of very small mud and
clay particles (too small to see)
Example: shale – well bedded, distinct layers
Clastic Sedimentary Rocks
»
Medium Grained Sandtone
»
Fine Grained Mudstone
Sedimentary Classifications
2) Non – Clastic - produced by chemical or
biological methods, usually in water.
Non – Clastic Rocks
a) Chemical –produced by precipitation of
inorganic chemical material (minerals).
-Usually made on the floor of an ocean,
sea, or lake.
-May form from evaporation.
Chemical Rocks
• Limestone is made by precipitation of calcite.
• Because its made of calcite, limestone fizzes
when acid is dropped on it.
Chemical Rocks
• Rock gypsum is an evaporate made of gypsum.
Chemical Rocks
• Rock salt is an evaporate made of halite (salt).
Non – Clastic Rocks
b) Organic (Biogenetic) – made from material
produced by living organisms.
Organic Sedimentary Rocks
• Peat, turns into……………..bituminous coal
Organic Sedimentary Rocks
• Coquina is made of shells. It is a type of
limestone because it’s held together by calcite.
• Only sedimentary rocks can have fossils!
Sedimentary rocks forms in flat, horizontal layers
with the oldest layers on the bottom.
Flashback!!!
• Rocks are combinations of minerals.
• Minerals can be made by
– Cooling magma…minerals made this way form
igneous rocks.
– Precipitation in a supersaturated
solution…minerals made this way form chemical
sedimentary rocks.
– Evaporation of a solution…minerals made this way
form chemical sedimentary rocks.