tree mold

^{USGS PHOTO GLOSSARY OF VOLCANIC TERMS}

Fluid basaltic lava may preserve the shapes of trees and other objects by solidifying around them. Tree molds are formed when lava surrounds a tree, chills against it, and then drains away. The standing structure left behind is often called a lava tree.

Tree trunks engulfed and incinerated by lava leave cylindrical hollows, or tree molds, where lava solidified against them; tree molds often preserve the original surface texture of the tree. Tree molds are found within standing lava trees and on the surfaces of lava flows. They are common in pahoehoe flows and occasionally found in `a`a flows.

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Photograph by K. Shickman on 23 January 1990

A tree mold glows several hours after pahoehoe lava surrounded a tree and burned its trunk until the tree fell onto the lava flow; the trunk is visible in upper right. The glow is from the hot lava below.

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Photograph by C. Heliker on 6 September 1986

These tall lava trees formed when lava cooled and solidified around the trunks of trees before the peak part of the flow drained away. The hollow tree mold is in the middle of the lava trees (where the trunk was burned away or turned to charcoal).