Popcorn-rocks solve the mystery of the magma chambers

Science Daily ^ | 11/2/2016 | Uppsala Universitet

[JimSEA]

Since the 18th century, geologists have struggled to explain how big magma chambers form in Earth's crust. In particular, it has been difficult to explain where the surrounding rock goes when the magma intrudes. Now a team of researchers from Uppsala University and the Goethe University in Frankfurt have found the missing rocks -- and they look nothing like what they expected.

Researchers have previously proposed that the roofs and walls of magma chamber were either melted and assimilated into the magma, or that they would sink to the bottom of the magma chamber. However, enough evidence for either of these hypotheses have not been forthcoming, and researchers now propose a third possibility.

"We show that rock fragments from the roof of the magma chambers could have been expelled, similar to popcorn that is thrown out of a hot pan! We have found them in rocks that have been ejected in volcanic eruptions. The rock fragments are full of bubbles and have very low densities, and they look a lot like popcorn," says Steffi Burchardt, researcher at the Department of Earth Sciences, Uppsala University.

[JimSEA]

Upthrusts such as those spectacular ones in the Andes does answer the question, "The magma intrusion displaces the older, cooler rock doesn't it?" There are rock inclusions in all types of lava however and these are from the surrounding cooler rock the lava pushes through. Interesting article as simplistic answers are almost always incomplete.

[Gadsden1st]

I may need to find some of these to munch on. Regular popcorn just isn’t doing it.

[pinkandgreenmom]

Great article! My homeschooled 6th grader is studying about rocks right now and we had fun with this article. He also loves popcorn and loved the connection (and neither of us knew about the water droplet in the popcorn...). Thanks for posting!

[Red Badger]

[Red Badger]

Post #4............

[smokingfrog]

http://www.heritagedaily.com/wp-content/uploads/2016/11/pop1.png

[JimSEA]

Sorry, this is actual popcorn rock, the photo for some reason has actual popcorn. My bad.

[JimSEA]

My post #7 has a photo of actual popcorn rock. For some reason Science Daily posted a picture of actual popcorn. My bad. I looked at it more closely and thought “That picture is close but not right”. The real stuff is a lot prettier and more interesting. Post seven is the real stuff.

[pinkandgreenmom]

Thank you for posting the photo - I’ve never seen anything like that!

[T-Bone Texan]

wow, it looks very geode-esque!