Holbrook in Navajo County, Arizona — The American Mountains (Southwest)
From Wood to Stone
Photographed By Denise Boose, September 2, 2013
1. From Wood to Stone Marker
Photo Caption:
Forest devastation after the 1980 eruption of Mount Saint Helens in the state of Washington provided at least two requirements for the petrification process – wood and silica – producing sediment (in this case volcanic ash).
Inscription.
From Wood to Stone. . Approximately 225 million years ago, during the Triassic Period, a floodplain existed here – littered with fallen trees. Periodic flooding buried the logs beneath layers of silt. Over time, silica-laden waters filtered through these deposits and petrified the wood by encasing the trees’ organic material with minerals., Iron oxides give petrified wood its distinctive red, yellow, and orange hues; manganese oxides produce blues, purples and deep blacks, while the original carbon produces the shades of gray. Centuries of erosion washed away concealing sediment deposits to expose these remnants of Triassic woodlands., Could today’s woodlands become petrified forest of tomorrow? Geologic forces similar to those of the Triassic period still shape the Earth’s surface, and may create the preliminary conditions for future petrification., Side Bar: , The processes that created petrified wood here ceased millions of years ago. Petrified wood and other fossils are irreplaceable resources to be cherished undisturbed.
Approximately 225 million years ago, during the Triassic Period, a floodplain existed here – littered with fallen trees. Periodic flooding buried the logs beneath layers of silt. Over time, silica-laden waters filtered through these deposits and petrified the wood by encasing the trees’ organic material with minerals.
Iron oxides give petrified wood its distinctive red, yellow, and orange hues; manganese oxides produce blues, purples and deep blacks, while the original carbon produces the shades of gray. Centuries of erosion washed away concealing sediment deposits to expose these remnants of Triassic woodlands.
Could today’s woodlands become petrified forest of tomorrow? Geologic forces similar to those of the Triassic period still shape the Earth’s surface, and may create the preliminary conditions for future petrification.
Side Bar:
The processes that created petrified wood here ceased millions of years ago. Petrified wood and other fossils are irreplaceable resources to be cherished undisturbed.
51.869′ N, 109° 47.46′ W. Marker is in Holbrook, Arizona, in Navajo County. Marker is on Petrified Forest Road, on the right when traveling north. Touch for map. Marker is in this post office area: Holbrook AZ 86025, United States of America. Touch for directions.
Credits. This page was last revised on December 28, 2018. It was originally submitted on September 28, 2013, by Denise Boose of Tehachapi, California. This page has been viewed 623 times since then and 12 times this year. Photos:1, 2, 3, 4, 5, 6. submitted on September 28, 2013, by Denise Boose of Tehachapi, California. 7. submitted on December 20, 2018, by Mandy Kirby of Clovis, California. • Syd Whittle was the editor who published this page.