Rocks THE MATERIAL THAT MAKES UP THE SOLID PARTS OF EARTH

How to take notes!!

What are rocks? A rock is a naturally formed, non-living earth material Rocks are made of collections of grains that are solid. Texture is a description of the size, shape, and arrangement of mineral grains.  The different colors and textures seen in this rock are caused by the presence of different minerals.

3 types of rocks  Igneous- forms when magma, cools and hardens. Magma is lava when it is exposed at the Earth’s surface.  Sedimentary- when rocks and other organic matter have been broken down into smaller fragments by erosion and are compressed together.  Metamorphic- undergo tremendous pressure and extreme heat to change or alter an existing rock.

Rock Cycle  Physical and Chemical properties of rocks are constantly changing in a natural, never-ending cycle  The processes involved in the rock cycle often take place over millions of years.  First developed by James Hutton, an eighteenth century scientist often called the “Father of Geology” James Hutton “Father of Geology”

The Rock Cycle Processes: Crystallization Erosion/Sedimentation Metamorphism

Rock Cycle Processes  As the magma cools, different crystals form at different temperatures, undergoing crystallization. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals.  Weathering wears rocks at the Earth’s surface down into smaller pieces. The small fragments are called sediments. o During sedimentation, the sediments are laid down or deposited. In order to form a sedimentary rock, the accumulated sediment must become compacted and cemented together.  When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes metamorphosed. Metamorphism may change the mineral composition and the texture of the rock.

Igneous Rocks Intrusive - The magma that forms these rocks intrudes, or enters into other rock masses beneath Earth’s surface. The magma cools at a slow rate and then hardens Extrusive - When magma reaches the Earth’s surface it cools at a rapid rate and forms crystals. This flowing lava is molten rock that will harden into an igneous rock.

Textures of Igneous Rocks  Coarse-Grained Igneous Rock- Intrusive igneous composed of large mineral grains  Fine-Grained Igneous Rock- Extrusive igneous composed of small mineral grains that cannot be seen with the naked eye  Other Igneous Rock textures- when magma cools slow at first and then cools more rapidly as it nears Earth’s surface. Composed of Large crystals embedded within a mass of smaller ones.

Sedimentary Rocks form by the compaction and cementing together of sediments, broken pieces of rock-like gravel, sand, silt, or clay

What can you find in sedimentary rocks?  Remains of ancient plants, animals is Fossils, they are preserved in sedimentary rock  Concretions are formed when minerals from fluids build up and harden around a nucleus.  Geodes, are crystallized mineral formations.

How is limestone formed in oceans? * Animal shells are made up of Calcium Carbonate, that is not able to dissolve. * The remains harden and compact to create limestone.

This sedimentary rock is made of sand that is cemented together to form a sandstone.

Metamorphic Rock

What do you think?  Stone tools were important to early humans. Are rocks still important to humans today?  Tell me how rocks are still important to humans today in life. Write in complete sentences in your notebook.

Fill in the Blank Name___________________ Class______________ Date________ Fill in the blank with the appropriate term. 1. __________ is a description of the size, shape, and arrangement of mineral grains in a rock. 2. The process in which mineral crystals form as molten rock cools is called __________. 3. The process in which a rock changes due to heat or pressure inside Earth is __________. 4. The continuous series of processes by which rocks change from one type to another is called the __________. 5. __________ is the deposition of transported sediments. 6. The wearing away of rocks at Earth’s surface is known as __________. 7. After molten rock flows onto Earth’s surface, it is called __________. Erosion Magma Weathering Crystallization Metamorphic Rock Cycle Texture

The Rock Cycle