Rock Types. Sedimentary Rocks. Lithification = becoming a rock

Size: px

Start display at page:

Download "Rock Types. Sedimentary Rocks. Lithification = becoming a rock"

Barnaby Clyde Garrison
5 years ago
Views:

1 Rock Types Sedimentary Rocks lithification make up about 70-75% of the rocks at the Earth s surface form environments such as beaches, rivers, oceans and anywhere that sand, mud, clay and other types of sediments collect layered rock that is formed from the process of compaction and cementation of sediments formed from sediment that has been weathered, eroded and deposited from existing rock and other material such as plants or animal remains. only rock in which fossils can be preserved Sediments undergo the process of lithification by compacting under pressure and filling pore space by cementation. Lithification = becoming a rock

2 Where is the only place you can find fossils? How are sedimentary rocks formed? What is sediment Weathering Two types of Weathering Weathering occurs in a variety of ways: Chemical In Sedimentary rocks From sediment a naturally occurring material that is broken down by processes of weathering and erosion the breakdown of rocks into smaller pieces called sediment Mechanical and Chemical Heat and cold may cause minerals within a rock to expand/shrink at different rates, creating cracks. Water may seep into cracks, freeze and split the rock. A raging river/ocean can smash rocks against each other. Sand carried by the wind or a glacier can act like sandpaper wearing away a rock. most likely caused by rain

3 weathering Compaction Cementation changing the chemical make-up of the rock rain absorbs carbon dioxide and sulfur dioxide from the atmosphere, forming carbonic acid and sulfuric acid, two liquids capable of dissolving other materials the squeezing together of sediment due to the immense weight of the many layers of rock and sediment This squeezing of layers results in reducing the thickness of each of the original layers When the layers are reduced in thickness, the spaces around each piece of sediment are also reduced This process leads to a tighter packing of the layers the changing of sediment into rock by filling spaces around the sediments with minerals. Dissolved minerals fill in the spaces between the sediment

the moving or rock and sediment from one place to another. Term erosion comes from erodere, a Latin verb meaning to gnaw.

4 Erosion Six main processes have an eroding effect: Sedimentary Rock Examples: particles. These liquid minerals act like glue or cement to bind the sediments together. Forming solid rock. the moving or rock and sediment from one place to another. Term erosion comes from erodere, a Latin verb meaning to gnaw. Erosion is what usually happens to the material loosened by weathering. wind gravity rain rivers oceans glaciers Shale, Breccia, Travertine, Coal, Chert. Clay Conglomerate, Sandstone, Limestone, `

5 Metamorphic Rock Metamorphic Found where? Comes from the Greek terms: Meta=change Morph=form So, metamorphism means to change form. in the Earth s continental crust metamorphism Formed by Examples of Metamorphic Change Doesn t completely melt rocks, but changes them into denser, more compact rocks. This process takes millions of years. the physical or chemical change by heat and pressure of an existing igneous, sedimentary or even another metamorphic rock into a denser form

6 Limestone changes to Marble Sandstone changes to Quartzite Shale changes to Slate Slate changes to Phyllite Phyllite changes to Schist Schist changes Gneiss Granite changes to Metamorphic Rock Examples: Gneiss Basalt changes to Greenstone Gneiss, Quartzite, Serpentine, schist, Marble, Muscovite, Phyllite, Slate Igneous Rocks

7 Classified by the size of their crystals Magma How do igneous rocks form? lava mixture of molten (liquid) rock, crystals and gas below the Earth s surface. Magmas are less dense than surrounding rock and will move upward. Because cooling of the magma takes place at different rates, the crystals that form and their texture exhibit different properties When lava cools and crystallizes (hardens) on the surface of the Earth. Igneous rocks that are formed above ground are called volcanic. Once magma makes it to the surface, it is known as lava.

8 Extrusive Rock When a volcano erupts, lava explodes from a volcano, cools and forms an extrusive rock. Extrusive rocks have small crystals and may need a microscope to be seen. Example = Basalt Note: Extrusive rock cools quickly and crystals do not have much time to grow, so they are small. Intrusive rocks Igneous Rock Examples: form when magma cools below the Earth s surface. The crystals are large enough to be seen with the unaided eye. Example = Granite Note: Intrusive rock cools slowly so crystals have time to grow. Pumice, Ryolite, Granite, Diorite, Andesite, Scoria,

9 Gabbro, Syenite, Basalt, Obsidian

Rocks. Section 1:Igneous Rocks. Section 2:Sedimentary Rocks. Section 3: Metamorphic Rocks. Section 4: The Rock Cycle

Rocks. Section 1:Igneous Rocks. Section 2:Sedimentary Rocks. Section 3: Metamorphic Rocks. Section 4: The Rock Cycle Rocks Section 1:Igneous Rocks Section 2:Sedimentary Rocks Section 3: Metamorphic Rocks Section 4: The Rock Cycle BILL NYE ROCKS https://www.youtube.com/watch?v=jvd- SPZLh5s What is a rock? Common Rocks