Florissant Fossil Beds near Florissant, Colorado.The Gilboa Fossils near Gilboa, New York.Mississippi Petrified Forest near Flora, Mississippi.The Petrified Forest near Calistoga, California.Ginkgo Petrified Forest near Wanapum Reservoir, Washington.Petrified Palm Deposits in the Catahoula Formation of Louisiana, Texas and Mississippi.Petrified Forest National Park near Holbrook, Arizona.In the United States, noteworthy locations where abundant fossilized wood can be seen include: One almost unbelievable material from Western Australia is known as " peanut wood" because of its ovoid markings, but those markings are actually boreholes drilled by a clam! Wood specimens in these locations are casts and molds rather than petrifications. It is especially abundant around coal seams, although many of the It is found where wood in sedimentaryĭeposits was replaced by minerals precipitated from groundwater. It is sometimesįound where volcanic activity covered plant material with ash, mudflows or pyroclastic debris. It is found in volcanic deposits and sedimentary rocks at many of locations worldwide. If you look closely you can see a spiral-shaped boring that traverses the width of this image (second row from the bottom). The "peanuts" are actually boreholes made in the wood by a shipworm which is a tiny species of clam. Peanut wood: A close-up of a slice of petrified wood from Australia known as "peanut wood" because of its white markings the size and shape of peanuts. Park can observe the petrified wood and photograph it however, collecting petrified wood in the park is prohibited. That is why areas of the Park are covered with a litter of petrified wood trunks, branches and fragments. Instead of eroding away, the wood accumulated on the ground surface as the surrounding mud rocks and ash layers were eroded away. The petrified wood is much harder and resistant to weathering than the mud rocks and ash deposits of theĬhinle. In the millions of years after the Chinle Formation was deposited, the area was uplifted and the rocks deposited above the Chinle These sediments, plant debris, and volcanic ash became part of a rock unit known today as the Chinle Formation. Trace amounts of iron, manganese and other minerals were included in the silica and gave the petrified wood a variety ofĬolors. The dissolved ash served as a source of silica that replaced the plant debris, creating petrified The soluble ash was dissolved by groundwaterįlowing through the sediments. Rapid burial allowed the plant debris to escape destruction by oxygen and insects. These eruptions blanketed the area in volcanic ash with a high silica content.
Fallen trees and broken branches were often buried by Up to 9 feet in diameter and 200 feet tall lived and died in these lowlands. Rivers flooded by tropical rain storms washed mud and other sediments into the lowlands. About 225 million years ago, this area was a lowland with a tropical climate and covered by a denseįorest. The most famous locality for observing petrified wood is Petrified Forest National Park near the community of Holbrook in This specimen shows the growth rings, cellular structure, and external bark. Petrified wood: A nice piece of petrified wood representing a limb cross section. When the Chinle weathers away, the log will be lowered to the ground surface. At the top of the gulley, a "pedestal log" is suspended on a column of Chinle Formation. Petrified logs: An accumulation of petrified logs in a gulley at Petrified Forest National Park. These specimens with near-perfect preservation are unusual however, specimens thatĮxhibit clearly recognizable bark and woody structures are very common. Some specimens of petrified wood are such accurate preservations that people do not realize they are fossils until they pick The result is a fossil of the original woody material that often exhibits preserved details of the bark, wood, and cellular structures. With silica, calcite, pyrite, or another inorganic material such as opal. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material It forms when plant material is buried by sediment and protected from decay due to oxygen and organisms.