Quiz review for Weathering &

Sedimentary Rocks

• Where does sedimentary rock almost always form?

•UNDER WATER

• For any rock to become sedimentary rock, what process must happen to it first?

• It must be weathered into small pieces or a chemical solution

•What are clasts?

•Small bits and pieces of weathered rock

• What is Clastic sedimentary rock?

•Rock made of bits and pieces of other rocks

• A Clastic sedimentary rock composed mostly of sand is called ________.

•Sandstone

•What is weathering?

•The natural breakdown of rock

•What are the 3 types of weathering?

•Mechanical

•Biological

•Chemical

•How do we know mechanical weathering?

•Movement that is not caused by plants or animals

• How does “abrasion?” wear away rock?

•Water or wind rubs particles of sediment against the rocks to wear them down

• . Does air or water abrasion do more weathering?

•WATER

• . What is exfoliation?

•Rock peeling off in layers

•What causes exfoliation?

•Daily temperature changes

• . How does frost wedging work?

• Water freezes in cracks, expands, and forces the crack to enlarge

• How do landslides cause rock to weather?

• Falling rocks break when they hit the bottom

• What is “unloading,” and how does it affect rock?

• When the overlying rock weathers away it’s weight is unloaded from the lower rock allowing it to expand and crack.

•What is “Chemical Weathering?”

• Rock breaking down due to exposure to chemicals

• How does acid rain affect chemical weathering?

•It dissolves certain types of rocks

•What is a “sinkhole?”

• The top of a cave that has collapsed to the surface

•What types of rock tends to support sinkholes?

Carbonates, which are:

Limestone

Marble

calcite

• What is a famous and beautiful example of chemical weathering?

•Luray Caverns

•Mammoth Cave

• . What can oxygen bring about in the rock?

•Rusting, which expands and weakens the rock

•What is “Biological Weathering?”

Rock breakdown that is caused by plants or animals

•How do lichens start the weathering process in rocks?

•They produce an acid that etches the rock and makes it ready for mosses to grow there

• How does moss affect the weathering process?

• It holds rainwater that may be acidic, & builds up soil for plants with strong roots

•What is “Root Wedging?”

• When plant roots grow into a crack in the rock and grow, causing the crack to enlarge

•What is “tallus”?

• A slow motion avalanch of small rocks down the side of a mountain. They slowly grind each other to bits

• What rock is the first rock in the “Rock Cycle?”

•Igneous Rocks were the first rocks on Earth

• Why is one characteristic not enough to identify a mineral or rock?

• Because many minerals share many of the same characteristics

• What is the main thing that tells you when weathering is chemical?

•Chemical reactions weaken or dissolve the rock

• A Clastic sedimentary rock composed mostly of clay is called ________.

• Claystone or shale

A Clastic sedimentary rock composed mostly of silt is called ________.

•Shale

• A Clastic sedimentary rock composed mostly of sand and rounded pebbles is called ________.

•Conglomerate

• A Clastic sedimentary rock composed mostly of sand and small broken rocks is called ________.

•BRECCIA

• What makes a sedimentary rock Organic?

•Some part of it was once alive

• An organic sedimentary rock composed mostly of tiny shells is called ________.

•Coquina

• An organic sedimentary rock that is made from disolved shells an deposited chemically by precipitation is called ________.

•Limestone

• Rock that was precipitated by evaporating water and was never alive is called _________ sedimentary rock.

•Chemical

• What are 2 examples of chemical sedimentary rock?

• Rock salt and Gypsum

What is peat made of?

•Moss

•What is all coal made of?

•Moss

•Ferns

•Ancient conifers

• The first stage of coal that is a true rock is called _____________ or brown coal

•Lignite

• The second stage of coal that is a true sedimentary rock is called _________ Coal

•Bituminous

• Sometime after a thick layer of plants formed in the coal fields, what had to have happened to cause them to be covered with sedimentary rock?

• The area flooded

• Why must sedimentary rock always cover coal?

• It provides the pressure that causes the non-carbon molecules to be driven out of the plants

• Bituminous coal that becomes metamorphic is called ______________

• Anthricite coal or hard coal

• This is NOT sedimentary, it is metamorphic

weathering Mechanical Chemical BiologicalIce wedging

rockslideRoot wedging

Acid rainWater abrasion

Wind abrasion

Unloading

Lichens

Exfoliation

Rusting

weathering Mechanical Chemical BiologicalIce wedging X

rockslide X Root wedging X

Acid rain XWater abrasion XWind abrasion X

Unloading X

Lichens X

Exfoliation X

Rusting X

• SOME STUDY IS HIGHLY

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