Researchers used quartz from fossilized wood to trace how Europe developed.
A polished piece of fossilized wood may look like little more than a decorative stone, yet the quartz inside it can preserve the history of an entire region for hundreds of millions of years. Geologist Dr. Steffen Trümper of the University of Münster and his colleagues have demonstrated for the first time that fossilized wood can serve as a natural archive of long-term geological change.
The researchers showed that mineralized wood can record how a sedimentary basin sank over time and preserve evidence of later tectonic events. Their results greatly extend the known timeline of wood mineralization, revealing a process that continued across much of Earth’s geological history.
The study examined the Saale Basin in central Germany, which began forming about 300 million years ago. Its rocks are among the oldest deposits within the much larger Central European Basin System. The findings were published in Scientific Reports.
Ancient trunks preserve a regional history
The researchers studied fossilized trunks from the Kyffhäuser Mountains in northern Thuringia, Germany. Known since at least the 18th century, some of the trunks reach 20 meters in length and lie within fluvial redbeds, reddish sediments deposited by ancient river systems.
Iron oxides give the deposits their color and point to a warm climate with pronounced dry seasons. Floodwaters buried the trees, which once grew in tropical dry forests on the supercontinent Pangaea. About 300 million years ago, this part of Europe was close to the equator and supported now extinct relatives of modern conifers.
The Kyffhäuser Mountains are considered a reference site for this kind of deposit, which developed repeatedly in sedimentary basins across Europe. Together, these locations form one of the Northern Hemisphere’s largest concentrations of fossilized wood.
The surrounding rocks also represent some of the earliest deposits in the Central European Basin. That basin system remains economically important because it contains raw materials and groundwater and may offer opportunities for geothermal energy.
Quartz records five stages of change
The geological record is preserved in quartz that entered the wood and gradually replaced its original tissue during fossilization. The process began when dissolved silicic acid moved into the dead trunks and formed around their cell walls, preserving even very fine anatomical details.
Across millions of years, these early silica deposits crystallized into quartz and replaced the biological material piece by piece. The researchers found that this transformation was much more complex than previously recognized, involving changes in structure, chemical composition and the ages of different quartz phases.
Their analysis identified five successive generations of silica. Each formed from a different solution and retained evidence of the temperature, pressure and chemical environment present at the time.
Together, the five stages cover roughly 200 million years, beginning in the late Carboniferous and continuing into the Early Cretaceous. When the later uplift of the fossils back toward Earth’s surface is included, the record extends across as much as 300 million years. No previous study has documented such a long sequence of mineralization stages in fossilized wood.
To reconstruct this history, the researchers combined quartz cathodoluminescence, fluid inclusion analysis, oxygen and silicon isotope measurements, Raman thermometry, electron probe microanalysis, scanning electron microscopy and in-situ U-Pb dating, a method used to determine the ages of minerals and rocks.
“The tiny fluid inclusions in the quartz were particularly revealing, as they preserve information about the exact conditions during crystal growth,” explains Steffen Trümper.
Those microscopic pockets showed that portions of the wood were once buried between three and five and a half kilometers below the surface. At those depths, the fossils experienced temperatures ranging from 160 to 240 degrees Celsius.
Fossil wood could trace continents
The implications extend well beyond the Kyffhäuser Mountains. Because fossilized wood occurs in rock formations around the world, similar specimens could provide previously unavailable records of basin development and continental change.
“It is astonishing that a fossil, often no bigger than the palm of a hand, encapsulates the geological history of an entire region spanning hundreds of millions of years,” says Steffen Trümper. “A sequence of five stages of mineralization has never before been documented in fossilized wood. As fossilized wood occurs in many rock formations worldwide, this opens up a valuable source of information. It provides science with a new tool for tracing the evolution of continents.”
The results also show that not every piece of fossilized wood will preserve the same level of geological detail. Its usefulness for reconstructing basin history appears to depend less on the surrounding tectonic setting than on the climate and sedimentary conditions present when the wood was buried.
Reference: “Fossil wood cells recorded 300 million years of Europe’s tectonic history” by Steffen Trümper, Matthias Franz, Graciela Sosa, Alfons van den Kerkhof, Armin Zeh, Michael Tatzel, Andreas Kronz, Kirsten Techmer, Tommaso Di Rocco, Andreas Pack and Ronny Rößler, 14 July 2026, Scientific Reports.
DOI: 10.1038/s41598-026-60054-3
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