Lava Falls Trail Stop #5

Rising gases lifted past lava flows to unexpected heights as the rock cooled.

Quick Facts

Location:

34° 44’ 20.2”; -107° 58’ 56.4”

Significance:

Stop 5 of 9

Hot Gases Rise

Although you are slightly downhill from McCartys Crater, the inflation ridges around you might look like the opposite. However, these ridges formed from the lava rising up, rather than tall, thick lava flows flowing down.  

Lava can hold onto gasses, even as a liquid. Different minerals, such as silica, magnesium, and iron create a texture that can hold on to some gases easier than others. When lava cools, these gases rise upwards and outwards to escape into the air, and sometimes the lava expands with it. A similar process happens when bread bakes and expands in an oven.

Lava with more magnesium is usually more black in color, while high iron levels turn the rock red. Where do you see the differences in this amphitheater? Why do you think some areas inflated while others did not?