Rocks and Fossils

SEDIMENTARY ROCKS

100

Give two examples of sedimentary rock. (Ones we learned in class).

Conglomerate, sandstone, limestone, siltstone, shale, coal, fossil limestone, gypsum, halite.

200

Where are sedimentary rocks found?Why?

Sedimentary rocks are found on or near the surface of the Earth because weathering, erosion, and deposition of the sediment occurs on the surface.

300

Give the three types of texture of sedimentary rocks and explain each.

Coarse Grained-pebble sized pieces of rock. Medium Grained-sand sized pieces of sediment Fine Grained-Mud or Clay sized sediment.

400

Give 3 different examples of mechanical weathering and explain what occurs in each.

Wind-picks up pieces of sand/sediment and rubs up against other rock to break the rock down. Water-carries sand, sediment, or rock causing the sediment to grind and bump against other rock breaking it down. Ice-water is freezing in cracks or holes of rock and expanding causing the crack or hole to get larger. This process of freezing and thawing causes the rock to eventually break into smaller rocks. Glacier grinds the rock into smaller rocks is another way ice weathers rocks. Gravity-causes rocks to fall and hit other rocks powdering the rocks/breaking them into small rocks. Plants-roots wind their way into cracks and holes of rocks expanding the building pressure til eventually they crack and break into smaller rocks. Animals-burrow into the soil causing more water and space for the rocks to break down by water.

500

List the three types of sedimentary rocks and explain the formation and composition of each.

Clastic rocks are made of chunks of rock (known as clasts) cemented together. Chemical Rocks are made of minerals that dissolve in water and then compacts and cements together when water evaporates. Organic Rock is made of either dead sea life that has cemented together or where dead plants have changed into rock from the increase in temperature and pressure.

IGNEOUS ROCKS

100

Give two examples of Igneous Rocks

granite, gabbro, rhyolite, pumice, basalt, obsidian

200

What is the difference between magma and lava? In your explanation, be sure to talk about intrusive and extrusive.

Intrusive rocks are formed by magma slowly cooling below the earth's surface. Extrusive rocks are formed by lava quickly cooling above the earth's surface.

300

List and explain the two igneous rock compositions.

Felsic is light colored igneous rocks Mafic is dark colored igneous rocks

400

Where do igneous rocks form? What percent of the Earth's crust is made of igneous rock?

Igneous rock form above and below the Earth's surface. Igneous rock make up a majority of the crust and 60% of the Earth.

500

List the different igneous rock textures (there are 4) and give a short explanation of each.

Coarse grained the crystals/grains are visible Medium grained the grains are sand sized No Grained or Glassy the igneous rock cooled quickly Pyroclastic the igneous rock formed from a volcanic eruption.

METAMORPHIC ROCKS

100

Give two examples of metamorphic rock.

slate, phyloite, schist, gneiss, marble, and quartzite

200

What is metamorphism?

Metamorphism is where rock changes shape due to extreme heat and/or pressure.

300

List and explain the two ways metamorphic rock form.

Contact is where magma heats up the rock layer above and causes the rock to change. Regional is where the pressure becomes so intense from plate movement that the rock changes.

400

List and explain the two textures of Metamorphic Rock

Foliated is where minerals form in bands/planes. Non-Foliated is where the minerals are not arranged in bands or planes.

500

Explain (think back to our metamorphic rock activity) how sedimentary rock layers can form into metamorphic rock. Explain from the start to the finish.

Sedimentary rock layers form from weathering, erosion, deposition, compaction, and cementation. Then magma rises heating up the lake bed and increasing the pressure. This rise in pressure causes the rock to change shape and form a metamorphic rock.

ROCK CYCLE

100

How are rocks and minerals a like

rocks and minerals are solids and formed in nature.

200

What type of rock can a sedimentary rock form into?

Any other type of rock, sedimentary, metamorphic, and/or igneous rock.

300

Explain how a metamorphic rock will form. (make sure to use the vocabulary term metamorphism in your explanation.)

Metamorphic rock changes shape or goes through metamorphism when extreme heat and/or pressure changes the rock. This extreme heat will come from magma heating the rock. Extreme pressure comes from either magma's heat increasing the pressure or from plate movement.

400

Explain how igneous rocks form (make sure to include extrusive, intrusive,solidification/solidifies, magma, and lava in your explanation.)

Igneous rocks form below the surface or intrusively when magma cools and solidifies. Igneous rock forms above the surface or extrusively when lava cools and solidifies.

500

Explain how Sedimentary Rocks form (make sure to include weathering, erosion, sediment, deposition, uplift, strata, compaction, and cementation.

Sedimentary Rocks form when uplift exposes rocks to weathering. The weathering of the rock creates sediment that gets transported by erosion and then deposited in layers or strata. These layers will create pressure and compact together/cement together.

FOSSILS/GEOLOGIC TIME

100

E D C B A What Layer above is the oldest layer if undisturbed?Why?

By the definition of superposition, the bottom layer is the oldest because it would be the first layer deposited.

200

What type of rock would fossils most likely be formed in? Why?

Fossils are found in sedimentary rocks because they are deposited in layers burying the organisms. Also the process of forming metamorphic and igneous rock would destroy the evidence of the organism.

300

List four of the seven different ways fossils form.

Fossils formed in rock, Fossils in amber, Fossils in asphalt/tar, Petrification, Fossils in ice, Mold and Cast, Trace Fossils.

400

What does it mean if evidence of sea life is found in the desert?

That the desert was once under water.

500

Explain why our fossil record is incomplete.

Not all fossils have been found, some evidence has been erased, and also not everything will turn into a fossil.