1 / 23

Rocks

Rocks. Igneous Rocks. Intrusive: form when magma cools ___________ inside the Earth. Extrusive: form when lava cools ___________ on the Earth’s surface. Texture of Igneous rocks. Intrusive igneous rocks: Cool slowly Allows time for the minerals to form _________ crystals

hollye
Download Presentation

Rocks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rocks

  2. Igneous Rocks • Intrusive: form when magma cools ___________ inside the Earth. • Extrusive: form when lava cools ___________ on the Earth’s surface.

  3. Texture of Igneous rocks • Intrusive igneous rocks: • Cool slowly • Allows time for the minerals to form _________ crystals • Rocks with large crystals have a _____________ texture • Example: granite, gabbro

  4. Granite Gabbro

  5. Extrusive igneous rocks • Cool _____________ • Quick cooling doesn’t allow time for large crystals to form • This produces a ___________ texture • Example: basalt • Extremely rapid cooling cause NO crystals to form • Example: obsidian (volcanic glass) • Sometimes gasses are trapped in cooling magma and form bubbles • Example: pumice ,scoria

  6. Basalt Obsidian

  7. Pumice Scoria

  8. Igneous Rock Structures • Intrusion: underground rock mass made of intrusive rock • Extrusion: surface rock mass of extrusive rock

  9. Intrusions • Batholith: • ____________ intrusion • Large underground mass of rock which may cover hundreds of miles • Laccolith: • Magma flows between rock layers and spreads upward, pushing the rock above into an ___________

  10. Sill: • Sheet of magma ________________rock layers and hardens • They are always parallel to the ______________ rock layers • Can be thin (few centimeters) or thick (several hundred meters)

  11. Dike: • Forms when magma forces its way into existing fractures • Once magma hardens it is called a dike • Dikes cut ___________ rock layers (perpendicular to them)

  12. Extrusions • Volcanic neck: • Solidified central shaft of a volcano • Lava flow: • Erratically shaped mass of extrusive rock • Lava capped-plateau • Lava that spreads over vast area and hardens

More Related