Rock Formation Activity #19

Key Concepts Many of the materials used by people occur naturally on earth and are known as natural resources. Most rocks and minerals are non-renewable natural resources because they are formed by earth processes that take extremely long period of time. Rocks are grouped into three categories: sedimentary, igneous, and metamorphic, based on how they are formed. Fossils provide important evidence of how life and environmental conditions on Earth have changed.

Background Information Rocks can be grouped into three categories based on how they are formed 3 categories of rocks: 1. Igneous 2. sedimentary 3. metamorphic Stop and turn to your neighbor and give what you think the definition of each rock is

How do rocks form below the surface reach the surface? Discuss with your neighbor how you think this happens and be prepared to share your thoughts.

Answer…… Rocks form below the surface are pushed to the surface by geological processes. Weathering – caused by wind or water Weathering - Rocks get broken down into little pieces called sediments

Igneous Rocks Formed from the cooling of magma (molten rock) that is found below the surface of the earth. Cooling can happen at the surface of the earth (ex. Basalt rock formed from the cooling of volcanic lava) Cooling can below the surface of the earth (ex. Granite is formed from magma that cools before it reaches the earth’s surface.

Sedimentary Rock formed as pieces of older rocks and other loose materials get pressed or cemented together forming layers.

Metamorphic Forms when heat or pressure causes older rocks to change into new types of rocks. Example: A rock gets buried deep in the crust of the earth. Pressure and temperatures cause the rock to change and new minerals to grow in place of the originals minerals.