Download Clastic and Organic Rocks

Clastic and Organic Rocks
Sedimentary rocks Composition
• There are three types of sedimentary rock
composition
• Clastic (detrital)- that are formed from
mechanical weathering debris
• Chemical- that form when dissolved materials
precipitate from a solution
• Organic- form from the accumulation of plant
or animal debris
Sedimentary Rocks
• Sedimentary rocks are then broken down by
the two major textures that they display
• Clastic
– meaning that they are composed of discrete
particles that are compacted and cemented
together
• Non-clastic
– This means that they are consisting entirely of
crystals (forming from chemical compostion)
Shale
• Clastic (detrital)
compositions
• Clastic texture
• Is a laminated rock
– Means made up of many
thin layers
– The distinct layers are
called laminea
• Consist of particles that
are predominantly clay
– A.K.A. a “mudstone”
Oil Shale
• Clastic (detrital)
compositions
• Clastic texture
• Is a laminated rock
– Means made up of many
thin layers
• Contains significant
amounts of hydrocarbons
and plant remains in the
form of Kerogen
Organic Sediment
Bituminous Coal
• Organic composition
• Non-clastic texture
• Known as “soft coal” it
is high in carbonaceous
matter
• Forms from the
accumulation of organic
material
– Usually formed in
swamp environments