Because many people are not familiar with this exquisite and unique fossilized ancient wood, our description of how it was created is deliberately broad and non-scientific. The explanation focuses on the Chinle Formation in northern Arizona where our wood is mined.

Land in northern Arizona that is now desert, 225-200 million years ago (Late Triassic Period) was a rich, lush tropical forest of towering trees and dense vegetation near the equator. Trees in this ancient forest achieved heights of 100-200 feet and 4-10 feet in diameter. Large rivers and swamps were abundant.

Volcanoes were very common in that period of earth’s history. One day a large volcano erupted spewing thousands of tons of silica rich ash into the air. The giant trees were felled. Everything was covered or buried in volcanic ash and debris. Rivers and waterways were overwhelmed with it. Soon the area was inundated by massive roiling floodwaters which transported the trees great distances from where they had grown.

At this point, one of two things happened:

One scenario was:

By the time the trees’ tempestuous journey ultimately came to a halt in an aerobic environment, they were fairly well soaked through with water. The wood tissue inside the trunks began to disintegrate and turn to a pulpy mush. The silica precipitated out of the water and formed minute crystals of quartz (a form of silica) within the mush. Over time sediment continued to accumulate burying the trees ever deeper, cutting off the oxygen supply before the entire tree decomposed. In the meantime, mineral rich ground water continued percolating down through the sediment and the tree.

Under the influence of enormous heat and pressure, the silica eventually replaced the wood fibers. Other minerals in the ground water added their signature colors to the mix and everything hardened/fossilized together. This is known as wood replacement. When this occurs the cell structure and growth rings are not preserved. (This type of wood is commonly found in petrified forests throughout the world.)

This same process occurs with another type of petrified wood known as swamp bog. The only difference is that the trees ended up lying in swamp water. Here it was algae that created its characteristic green color. (This wood is primarily found in Nevada.)

The second scenario was:

The trees were quickly buried in sediment thus creating an anaerobic environment. Because of the absence of oxygen, instead of deteriorating, the wood stayed pretty much intact. Carried by mineral rich ground water, silica and other minerals seeped into the minute spaces between and within the walls of the wood cells.

When this occurs the replacement of organic tissue by minerals is so precise that the internal structure of the tree is completely preserved. Appropriately, this is called wood preservation. Hence growth rings are highly visible and cell structure can be observed under 30X power magnification. (Sequoia, fir, and oak found in Washington, Utah, and Nevada frequently show this degree of preservation.)

But – just to keep things interesting…..
bear in mind that Mother Nature is very creative and versatile so, depending upon where and/or what formation it came from, it’s fairly common to see replacement and various degrees of preservation in one piece of wood.