Help Please!? Rock Cycle Questions (URGENT!!!) Thank you!?

How do geologists classify rocks into groups?

Buy the origin, the mineral content and the crystal or particle size.

How is igneous rock formed?

Igneous rock forms when molten rock solidifies

Give four examples of igneous rock.

Granite

Basalt

Gabbro

Obsidian

How is sedimentary rock formed?

By particles of rock settling under water, by windblown sediments, by the accumulation of shells or other biological products or by crystallization from surface brine.

Give two examples of sedimentary rock.

Sandstone

Limestone

What two processes form metamorphic rocks?

Heat and pressure

Where are metamorphic rocks formed?

Under the surface - usually deep under

Give two examples of metamorphic rock.

Marble

Slate

Explain how each of the following formed. Provide a picture!

Guadalupe Mountains of western Texas

The rocks of the Guadalupe mountains consist of limestone reefs from the Permian Period 270 million years ago. The collission of the Pacific Plate with the North America plate in the last 80

million years has caused New Mexico and Eastern Texas to be raised. Erosion has removed the softer rocks, leaving the harder limestons as mountains.

Vermont’s Green Mountains

The rocks of the Green mountains consist of billion year old sedimentary rocks and granite from the Pre Cambrian. About 450 million years ago, the island chain known as the Taconic islands collided with Lauentia and created very high mountains. These have eroded down over the last 400 million years.

Half Dome in Yosemite Valley, California

Half Dome consists of granite, which solidified deep within the earth about 250 million years ago. Erosion exposed the granite to the surface about 100 million years ago. Streams cut through the terrain. In the ice age glaciers roughly followeed the streams and cut away the face of Half Dome.

Brainstorm and write some other rock formations either natural or man-made. What types of rock made up these formations? How were they formed? Feel free to research this!!!