https://www.youtube.com/watch?v=1SXaMH8gV6I Earth fissures are long, narrow cracks in the ground that form where the ground is sinking. They can erode very quickly, posing a hazard to nearby infrastructure. In Arizona, land subsidence--the sinking of the earth--is caused by groundwater withdrawal, meaning that earth fissures are a man-made--or anthropogenic--hazard. This video that I made as part… Continue reading Understanding Earth Fissures: A Man-Made Geohazard
Category: arizona
How do you form a mushroom rock?
Thanks to a variety of weathering and erosive processes, rocks can come in all shapes and sizes. The above rock from the McDowell Mountains near Phoenix, AZ has a peculiar shape similar to that of a mushroom! This rock is an example of a tor--an exposed mass of rock that abruptly rises above the surrounding ground… Continue reading How do you form a mushroom rock?
A journey to the center of the Earth | Peridotite xenoliths
You don’t need to go on a Jules Verne journey down to the center of the Earth, sometimes the center of the Earth is brought up to us! These rocks are examples of peridotite xenoliths. A xenolith is a fragment of rock that becomes enveloped by magma without being melted or incorporated into it. In these… Continue reading A journey to the center of the Earth | Peridotite xenoliths
Why are the Rocks of Sedona, Arizona Red?
Ever wondered why the rocks of Sedona are so vibrantly red? I made this video for Arizona State University’s Science Showcase competition, I’d greatly appreciate anyone who can view/share! Plus learning about geology is fun! (Source: https://www.youtube.com/)
San Francisco Volcanic Field
Located just north of Flagstaff, Arizona, the San Francisco volcanic field comprises an area of 1,800 sq miles and contains around 600 volcanoes. These volcanoes range in age from 6 million years old to less than 1,000 years old. Given their location on the Colorado Plateau, many volcanoes have experienced little erosion (like SP Crater… Continue reading San Francisco Volcanic Field
Hole in the Rock (Arizona)
Papago Park, located just a few minutes north of downtown Phoenix, features gorgeous Miocene sandstone formations and buttes, one of which is Hole in the Rock. As its name connotes, Hole in the Rock is known for its series of erosional openings and windows. The formation itself is composed of conglomeritic sandstone (individual clasts can… Continue reading Hole in the Rock (Arizona)
The Red Rocks of Sedona, Arizona
When compared to many igneous and metamorphic rocks, sedimentary rocks often aren’t the most visually stunning. However, you’ll be hard pressed to find more vibrant and beautiful rocks than the sedimentary rocks exposed at Sedona, Arizona. Rather than the standard hues of gray or beige, these sandstones, limestones and shales are breathtakingly vibrant shades of… Continue reading The Red Rocks of Sedona, Arizona
Emily Zawacki, Ph.D. 