Rocks & Minerals I-Surface Materials A-Bedrock & Soil: 1-Crust outer layer of earth consist of bedrock, rock fragments, and soil.

b-Soil- mixture of small rocks, organic matter, air and water. a-Bedrock- solid rock. When exposed to the surface it’s called an outcrop. (range from boulders to grains of sand) b-Soil- mixture of small rocks, organic matter, air and water. outcrop Rock Fragments Soil Rock fragments Bedrock Bedrock

B-Minerals 1-Rocks are composed of minerals, which are naturally occurring solid substances made of inorganic (nonliving) material. Minerals have certain physical and chemical properties by which they can be identified.

1. Physical properties of minerals include streak color, hardness, luster, cleavage, and color. Luster refers to how a mineral looks when it reflects light. {metallic, glassy, greasy, or earthy.} Streak color is the color of the powdered form of the mineral.

Hardness resistance of a mineral to being scratched Hardness resistance of a mineral to being scratched. Between I and 10, with I being softest and 10 the hardest.

copper penny will scratch Mohls Hardness Scale Hardness Mineral Test 1 Talc Finger Nail 2 Gypsum Will Scratch 3 Calcite copper penny will scratch 4 Fluorite Glass will 5 Apatite Scratch 6 K-felspar Steel 7 Quartz knife 8 Topaz Will 9 Corundum 10 Diamond Will Scratch all

Cleavage is a mineral's tendency to break along smooth, flat surfaces Cleavage is a mineral's tendency to break along smooth, flat surfaces. {Often causes a mineral to break into characteristic shapes}. Color is not always a reliable guide to a mineral's identity.

2. Minerals have chemical properties, how they react with an acid. {For example, calcite, the chief mineral in limestone and marble, fizzes when hydrochloric acid is placed on it.}

C-Rocks natural, stony materials composed of one or more minerals. Like minerals, rocks are identified by their physical and chemical properties.

Three groups of rocks: 1- Igneous rocks are produced by the cooling and hardening liquid rock. a-Melted rock ~ Magma underground ~ Lava on surface

b-Types of Igneous rocks Igneous rocks that form from rapid cooling of lava, called volcanic rocks, contain tiny crystals. -Basalt dark-colored volcanic rock composed of small crystals. The closer the magma is to the surface, the smaller the grain (crystal) size. Obsidian, a glassy, no individual grains.

~Igneous rocks that cools slow form large crystals. ~Granite is a light-colored igneous rock that contains large, easily visible mineral grains.

2- Sedimentary rocks form from particles called sediments that pile up in layers. These sediments may be small rock fragments or seashells. Sedimentary rocks usually form underwater. Stream carrying sediment Ocean Sedimentary rock

Common Sedimentary Rocks Rock Name Type of Sediment Place of Formation Sandstone Sand grains Shallow waters near a shore pounded by waves Shale Clay particles Deep, calm ocean waters; lake bottoms Limestone Tiny seashells Warm, shallow seas

3- Metamorphic rocks are produced when either igneous or sedimentary rocks undergo a change in form caused by heat, pressure, or both.

The rock cycle: is an illustration that explains how the three rock types are related to each other, and how processes change from one type to another over time.

Rock Rock Sediments Rock Igneous Rock Solidification Erosion Deposition Melting Metamorphic Rock Sediments Metamorphism Burial and Cementing Heat and/or Pressure Sedimentary Rock

II Earth History A- Interpreting Rocks= rocks contain information about that area's past. 1-Sedimentary rocks indicates the area was once covered by water. 2-Fossils in sedimentary rocks tell of past life and the environmental conditions

3- Horizontally layered sedimentary rocks are easy to interpret. The bottom layers are the oldest, youngest layers are at the top YOUNGEST OLDEST

FAULT PRESENT DAY INASION OF IGNEOUS ROCK FOLDED ROCK INVASION OF IGNEOUS ROCK

B-Fossils remains or traces of organisms that lived long ago. 1-Fossils form when a dead plant, animal, or footprint in mud, is covered by sediment that later hardens into rock. a-Almost all fossils are found in sedimentary rock

Brachiopod Trilobite Footprint Cephalopod

a. Rocks contain small amounts of C-Dating Rocks To determine the age of rocks, scientists use a technique called 1~Radioactive dating. a. Rocks contain small amounts of radioactive substances that change (decay) into non-radioactive substances at a definite rate. b. Using this technique, scientists have been able to assign dates to the Earth. c. Earth itself is about 4.5 billion years old.

2-Relative Dating: Section of sedimentary rock oldest sediment is on the bottom and the youngest is on the top. a. It only tells us that one fossil is older than another. Trilobite is an index fossil tells about the age of the rock layer .