Xenopumice (or Popcorn-Rocks) (image) Uppsala University Share Print E-Mail Caption Since the 18th century, geologists have struggled to explain how big magma chambers form in the 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. Credit Börje Dahrén Usage Restrictions creative commons Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.