January 17, 2013 Q-2 Pg.Daily Goal: We will be able to classify 3 different types of rocks. Homework: Turn in missing work! Finish weathering packet

Science Starter: 1. Explain why iron can be found in rocks.

2. How are mechanical and chemical weathering similar to physical and chemical changes? How are they different?

3. Why does metamorphic rock often have bands of different colors in the rock?

Classification of Rocks

Sedimentary

Sedimentary Rock: rock formed fromlayering of sediment (broken pieces ofrock)

SANDSTONE

Sedimentary

Sedimentary rock is made of large pieces of sediment such as pebbles and stone.

CONGLOMERATE

SEDIMENTARY

• Clastic (chunks of other rocks)• Bioclastic (shells, organic remains)• Crystalline (crystals of salt)• Similar-colored layers

Clastic - Rocks composed of fragments of pre-existing rocks; fragmental

Bioclastic - Rocks derived from shell fragments or other organic remains

Crystalline - Rocks composed of crystals

Metamorphic

Metamorphic Rock: rock formed from heat and pressure

In some metamorphic rocks, you can see where the mineral grains are flattened from the heat and pressure!

GNEISS

Metamorphic• Metamorphic rocks

are rocks that have morphed into another kind of rock.

SCHIST

METAMORPHIC

• Foliation (layers)• Microscopic mica crystals• Stretched/distorted pebbles or fossils

Igneous

• Igneous Rock: rock formed from the cooling of magma.• The cooling

magma gets caught in pockets and cools to form igneous rock

IgneousYou can see here pockets of air formed during cooling.

SCORIA

OBSIDIAN

Obsidian rocks are formed when lava cools quickly above ground

IGNEOUS• Vesicular• Coarse-grained• Glassy

Vesicular - Rock that has gas pockets

Coarse - Rock that has a chunky, large particles

Glassy - Rock that has a smooth, glass-like texture

Discussion Question 1. Why is it unlikely that fossils would be found

in igneous rocks?

Discussion Question 2. If a metamorphic rock

contained fossils, how might they look?

Discussion Question 3. Why might igneous rocks be porous (or have

little holes)?

Discussion Question 4. What is the difference between erosion and

weathering?