Presentation on theme: "Sedimentary Rocks. Sediments (notes) Bits of rock and soil which have been broken down from larger rocks. Sediments are “glued” together to form sedimentary."— Presentation transcript:
Sediments (notes) Bits of rock and soil which have been broken down from larger rocks. Sediments are “glued” together to form sedimentary rocks.
Types (notes) Clastic – Inorganic pieces cemented together Bioclastic – Organic pieces (shells, plant remains) cemented together. Crystalline – Formed from evaporites
How to make a clastic sedimentary rock. (notes) Step 1: Layers of sediment are deposited by air, water, or ice. Step 2: Over millions of years, as the layers are buried under more sediment, the weight pressing down on the layers squeezes all water out. Step 3: As the water disappears, the particles are cemented together by salt.
How to make a clastic sedimentary rock (notes) This process is known as Compaction and Cementation
How to make a crystalline sedimentary rock (notes) Water carries a lot of dissolved particles (i.e. salt) As the water evaporates it leaves behind the dissolved particles. These particles become cemented together to form a solid rock (i.e. rock salt)
What they look like (notes) Sedimentary rocks look similar to the sediments that made them.
Sandstone (notes) Formed from layers of sand from deserts, sand dunes and beaches
Limestone (notes) Formed from the crushed shells of animals living in warm shallow seas. Mostly calcite Bubbles with acid
Shale (notes) Formed from clay which has settled in calm lakes and estuaries, and oceans.
Conglomerates (notes) Contains pebbles set in a cement of finer particles. Formed from riverbeds and beaches