Sediments will layer up over time, forming layered rocks
There are 4 main processes needed to form sedimentary rock: Step 1:EROSION (wash away) Forces of running water, wind, or ice that loosen & carry away fragments of rock Can you see the sediment moving in the water? Have you ever seen sediments being moved during a hard rain?
There are 4 main processes needed to form sedimentary rock: Step 2:DEPOSITION (drop down) Sediments settle out of the water or wind carrying them & settle to the bottom of a lake or ocean. Sediments move down the sloped land & settle at the bottom. Over time these sediments layer up.
There are 4 main processes needed to form sedimentary rock: Step 3: COMPACTION (smashed together) Process that presses sediments together. Thick layers of sediment build up over time & weigh down the layers compacting them.
Those smashed sediments can form into layers like the ones shown above.
There are 4 main processes needed to form sedimentary rock: Step 4: CEMENTATION (glued together) Dissolved minerals seep into spaces between particles (sediments) & then crystallize as they harden.
3 Types of Sedimentary Rocks 1.Clastic Sedimentary Rock Made from fragments that are squeezed together
Comparing 2 Clastic Sedimentary Rocks: Shale Forms from mud - tiny clay particles, quartz & calcite; Sandstone Forms from sand on beaches, ocean floor, river beds, etc
Comparing 2 more… Conglomerate From rounded sediments Breccia From larger, sharp fragments
3 Types of Sedimentary Rocks 2. Organic Sedimentary Rock Forms where the remains of plants & animals are deposited in thick layers
Comparing 2 Organic Sedimentary Rocks Coal From swamp plants buried in water for millions of years (plants peat coal) Limestone Forms from hard shells w/calcite from seashells, coral, clams, oysters or skeletons that pile up on the ocean floor for millions of years slowly changing the sediment to limestone
Use for coal & a location of limestone… Coal Limestone *** Limestone in England where there was once H 2 O covering the land. Plant Bowen is a power plant that uses coal. Has anyone seen this before? It’s not too far away!
3 Types of Sedimentary Rock 3. Chemical Sedimentary Rock Forms when minerals that have been dissolved in a solution with water, crystallize
Examples of Chemical Sedimentary Rock Limestone *** Another form of limestone forms from calcite in seas, lakes & underground caves – forms caverns & sinkholes in the ground when it is eroded by ground water Rock Salt Forms from halite when evaporation leaves salt behind
Comparing 2 Chemical Sedimentary Rocks Limestone *** Rock Salt 600 million year old rock salt being mined in the Himalayan Crystal Rock Mine. Ruby Falls cave is made of limestone! How did the cave form?
Uses: What things have been made from Sedimentary Rock? Flint: Arrowheads Sandstone: THE WHITE HOUSE Limestone: Blocks & slabs for building, making cement & steel, flooring
Possibly the coolest thing about Sedimentary Rock… FOSSILS are always found in Sedimentary Rock ONLY! Why??? (this might be a good test question…)