| How Does Wood Become Petrified? Usually, it takes over 100,000 years for it to be completely turned into stone, but in the Seward Peninsula it only took a few years! The astonishing rapid permineralization of forests in Kenai Fjords National Park has once again proven that "Alaska is the Land of Extremes". |
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| The phenomenon of rapid permineralization occurring was only a theoretical premise until the 1964 earthquake. The largest earthquake in the Northern Hemisphere of 9.2 on the Richter scale caused 70m (230ft) tsunamis that inundated the coastal areas with seawater at depths of 3m to 15m (11.8ft to 59ft). The long submersion, up to 5 years in seawater, caused the trees to replace the water in their tissues with seawater that contained silica and other minerals. Organic tissue, like wood, contains pores and spaces. The seawater fills the pores of the organic tissues and moves through the cellular spaces. During this process, the saturated water evaporates and the excess minerals are deposited on the cells and tissues. This process creates many layers of silica that replaces the organic tissue and turns a once viable tree to stone. |
| Petrification process usually requires wood to be covered with such agents as volcanic ash, lava and mud flow, sediments in lakes and swamps, or material washed in by a violent flood. The afore mentioned agent must exclude oxygen to prevent decay of the organic tissue, since mineralization is usually a slow process. |
| Once wood becomes petrified, it can last for eons. For example, the Petrified Forest National Park in Northeastern Arizona has petrified wood that has been preserved for millions of years. During the Triassic Period over 225 million years ago, it used to be a semi-tropical forest with a range of volcanic mountains. The volcanic ash decomposed and released chemicals into the water that seeped into the fallen logs. The chemicals reacted with the organic material in the wood and formed quartz crystals. The petrified wood is very colorful because of the many types of minerals other than silica within their water source. |
| Minerals saturating the water gives the petrified wood color. Some of the minerals causing the colors are: |
| Copper, Cobalt, Chromium cause green and blue |
| Manganese cause pink |
| Carbon cause black |
| Iron Oxides cause red, brown, and yellow |
| Manganese Oxides cause black |
| Silica cause white and gray. |
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| Article by Lesa Hollen |
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| Additional Information please visit: |
| Kenai Fjords National Park Web Site www.nps.gov/kefj/ |
| Petrified Forest National Park www.usparkinfo.com/petrified.html |
| University of Alaska Museum Web Site: www.uaf.edu/museum/ |
