Terms in this set (50)
What do you see along a beach?
Particles of Sediment - (Sand Grains, Mud, Pebbles)
Small, solid pieces of material that come from rocks or living things
What may sediment include?
Shells, bones, leaves, stems, and other remains of living things
When do sedimentary rocks form?
When sediment is deposited by water and wind
How are most sedimentary rocks formed?
Through a series of processes: erosion, deposition, compaction, and cementation
What are destructive forces constantly doing?
Breaking up and wearing away all the rocks on Earth's surface
What are examples of destructive forces?
Heat and Cold, Rain, Waves, & Grinding Ice
What do the forces of erosion form?
What happens in EROSION?
Running water, wind, or ice loosen and carry away fragments of rock
Eventually the moving water, wind, or ice ___& ___ the sediments in ____,
Slows, deposits, layers
What happens if water is carrying the sediment?
Rock fragments & other materials sink to the bottom of a lake or ocean
What is DEPOSITION?
The process by which sediment settles out of the water or wind carrying it
What is COMPACTION?
The process the presses sediment together
What happens in compaction?
1)Thick layers of sediment build up gradually over millions of years 2)These heavy layers press down on the layers beneath them 3)The weight of the new layers further compacts the sediments, squeezing them tightly together
How are the layers of sediment often viewed?
Often remain visible in sedimentary rock
What happens while compaction is taking place?
Minerals in the rock slowly dissolve in the water
What is CEMENTATION?
The process in which dissolved minerals crystallize and glue particles of sediment together
What happens IN cementation?
Dissolved minerals seep into the spaces between particles and then harden
How do geologists classify sedimentary rocks?
According to the type of sediments that make up the rock
What are the 3 major sedimentary rocks?
Clastic, Organic, Chemical
Different ____ form each of the sedimentary rocks
What are most sedimentary rocks made of?
Broken pieces of other rock
A sedimentary rock that forms when rock fragments are squeezed together
Sizes of Rock Fragments:
Range from clay particles that are too small to be seen w/o a microscope to large boulders that are too heavy to lift
What are clastic rocks grouped by?
The size of rock fragments, or particles of which they are made
Common Clastic Rocks:
Shale, sandstone, conglomerate, breccia
From what does shale form?
Tiny pieces of clay
Process which shale forms from:
Water deposits the clay particles in thin flat layers
From what does sandstone form?
Sand on beaches, ocean floors, riverbeds, sand dunes
Most sand particles consist of ___:
What do some sedimentary rocks contain a mixture of?
Rock fragments of different sizes
If fragments have rounded edges...:
Form a clastic rock called conglomerate
What is Breccia made up of:
Large fragments with sharp edges
When does organic rock form?
When remains of plants and animals are deposited into thick layers
Substances that were once part of living things or were made by living things
Formed from remains of swamp plants buried in water. As layers build up, weight of the layers squeezes the decaying plants, forming coal.
Forms in the ocean when dead animals' shells pile up on the ocean floor over millions of years to a depth of hundreds of meters. Then compaction and cementation change the sediment to limestone.
Ocean Animals & Shells:
Coral, clams, and oysters have hard shells/skeletons made of calcite.
2 ways Chemical Rock is formed:
Minerals dissolved in a solution crystallize OR Mineral deposits left in lakes or seas evaporate.
When calcite that's dissolved in lakes, seas, or underground water comes out of a solution and forms crystals.
How does rock salt form & what is it made of?
Halite, and it forms by evaporation
How have people used sedimentary rocks?
Building materials and tools
What did people use flint for?
Why was flint good for arrowheads?
It is a hard rock and can be formed to a point
How is flint formed?
When small particles of silica settle out of water
____&____ have been used as building materials.
Sandstone & Limestone
What is the White House built of?
Sandstone & Limestone qualities:
Soft enough to be easily cut into slabs
When do builders today use Sandstone & Limestone?
As the outside walls of buildings
Limestone's Industrial Uses:
Used in the making of cement and steel