Basalt is defined by its mineral content and texture. It is usually grey to black, but does weather sometimes to brown or rust color with a rust-red due to oxidation of its iron oxides. The redder the color the higher the iron level
The Basalt rocks are mostly dark but as you read above it does vary some in color. When the basalt rocks cool, depending on how fast they cool and how much gas was in the rocks you’ll see bubbles sometimes as large as 2 to 3 feet. The ones around here are more like the pictures above.
There are six types of volcanoes. They make up all the volcanoes on Earth. The six types are Fissure, Shield, Dome, Ash-cinder, Composite, and Caldera.
Cinder Cone Volcanoes are cone shaped. They are the most common volcano in the world. Cinder is cooled magma that is pebble sized, it is usually red or black.
Dome Volcanoes are very much like Cinder Cone, but are wider (see diagram)
Composite volcanoes have a main magma vent and have off shoots from that main vent.
Shield volcanoes are dome shaped. These volcanoes are formed by lava slowly oozing out. The slowly oozing lava is what makes it dome shaped. The dome resembles a shield and that is how it got its name. The Shield volcanoes are usually huge like the islands of Hawaii and can reach 1000,s of meters in height.
Caldera Volcano’s (like Yellowstone!) These don’t look like a Volcano but are very, very explosive. These explosions are so strong they collapse and form a large caldera.
Fissure Volcanos done much look like volcano’s either, they are made from the lava flowing at a steady but gentle rate creating canals and slow sloops. They also get to be very spread out.
Volcanic Rock is formed from magma erupted from a volcano. It differs from other Igneous rock by being Volcanic in origin. Volcanic rock is artificial and in nature form into Metamorphic rock.
These volcano’s in Arizona formed along weak points in fault lines and pushed up through and pop up all over the desert in Arizona and California.
The following Material were used for Reference:
- https://pubs.usgs.gov/bul/1457e/report.pdf
- U.S. Department of the Interior, Professional papers and Geological surveys
- Wikipedia
- www.azgs.az.gov/
- Geology.com
Logging Requirements: Please E-Mail me the answers, don't post any pictures of the site itself.
1. Type in GC70KW6 Volcano's out here. How many people with you today?
2. How do you think these bubbles where formed?
3. What are is main color you see?
4. What type of Volcano do you think this is and why?
5. How tall do you estimate it is?
6. Does this Volcano have the same color as the rock around it? Why do you think that is?
7. Do you think the rocks have a high or low content of Iron?