What is Magma?

“Magma,” definition 5: A confused or disordered body or mass of something.
—Oxford English Dictionary Online (20 September 2016)

Lava forms ropey pāhoehoe textures. How molten must the subsurface rock that fueled this lava be to get classified as “magma”? Credit: iStock.com/Justin Reznick

The authors of this article argue that we need a more precise definition of magma.

Defining Magma