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A team led by geologist Dr. Steffen Tr\u00fcmper analyzed the fossils at the\u00a0University of M\u00fcnster<\/a>. They showed that these stony logs work like a stacked recording of the ground far below.<\/p>\n In the right order, the quartz inside a single log<\/a> gives up the story of an entire region. That story runs across hundreds of millions of years.<\/p>\n Where the wood grew<\/p>\n Around 300 million years ago, this patch of ground sat near the equator on the supercontinent Pangaea. Tropical forests grew there in a warm climate that was broken by long, dry seasons.<\/p>\n The trees were early relatives of today\u2019s conifers, but this group has long since vanished. When floods tore through, they dragged fallen trunks into river channels and packed them under sediment.<\/p>\n The host rock is stained red by iron oxides. That rusty color is a fingerprint of heat and seasonal drought.<\/p>\n All of this happened in the Saale Basin, which counts among the oldest pieces of a vast basin system beneath central Europe. The rock there still holds groundwater and promise for geothermal<\/a> energy today.<\/p>\n Spots and preserved cells<\/p>\n A cross-cut through one of these trunks shows a strange pattern. Dark, pencil-like columns run through the pale quartz, a look that old collectors called pointstone.<\/p>\n The wood\u2019s real cells survive only inside those dark columns. Everything around them is blocky quartz that filled the gaps much later.<\/p>\n For a long time those spotty cross-sections fooled people into seeing tangled roots. They are really the cut ends of preserved wood, packed with fine anatomical detail.<\/p>\n Even the original carbon left a trace, cooked over time into graphite. That charred signature is one reason the team could tell lining from replacement.<\/p>\n How quartz traps clues<\/p>\n Petrification here turned on silica, the raw material of quartz and beach sand. Dissolved silica crept into the dead wood and settled tight against the cell walls.<\/p>\n Early on, it lined the finest structures inside each cell instead of replacing them outright. Over long stretches of time that soft silica firmed up into hard quartz.<\/p>\n Much of that silica came from volcanic ash that had weathered in the ancient<\/a> soil. As the ash broke down, it released the dissolved silica that soaked into the wood.<\/p>\n Every batch of quartz froze a snapshot of the moment it formed, holding the temperature, pressure, and chemistry of the water around it.<\/p>\n Five generations of silica<\/p>\n The trunks did not turn to stone in a single event. Close analysis pulled apart five separate generations of silica, each laid down after the one before.<\/p>\n The first two formed near the surface and kept the wood\u2019s cells intact. The next three formed deep underground, where hot fluids dissolved the old silica and blotted the cells away.<\/p>\n One of those deep stages washed the fossils in red hematite. A later one left behind pale crystals of the mineral baryte.<\/p>\n All told, the buried record covers 200 million years, from the late Carboniferous into the Early Cretaceous. No fossilized wood had ever shown a run of stages this long.<\/p>\n The team relied on tiny pockets of ancient fluid sealed inside the growing quartz. Each pocket held water from the exact moment its crystal grew.<\/p>\n \u201cThe tiny fluid inclusions in the quartz were particularly revealing, as they preserve information about the exact conditions during crystal growth,\u201d explained Dr. Steffen Tr\u00fcmper.<\/p>\n Those trapped droplets showed that parts of the wood once sat between 1.9 and 3.4 miles (3.0 and 5.5 kilometers) underground. Down at that depth the surrounding rock climbed to somewhere between 320 and 464\u00b0 Fahrenheit (160 to 240\u00b0C) .<\/p>\n The wood sank into that furnace and later rode back toward the surface. Its quartz held onto every reading from the trip.<\/p>\n How the basin moved<\/p>\n The three deep stages do more than erase cells. Each one marks a turning point in the life of the basin below.<\/p>\n The first deep event lines up with a pulse of heat as the crust relaxed after mountain building. Salty fluids rose from the basement and started replacing the wood.<\/p>\n The deepest, hottest stage came at maximum burial, when the trunks sat miles down in sinking ground. The last stage arrived as the whole region lifted and turned inside out.<\/p>\n In effect, the quartz logs a slow rhythm of sinking and rising. That rhythm matches the wider tectonic story written across central Europe.<\/p>\n What this means elsewhere<\/p>\n \u201cIt 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,\u201d said Dr. Steffen Tr\u00fcmper.<\/p>\n Most of these logs look like nothing more than polished stone on a shelf. Their real worth hides in the stacked layers of quartz.<\/p>\n \u201cA sequence of five stages of mineralization has never before been documented in fossilized wood,\u201d said Dr. Steffen Tr\u00fcmper.<\/p>\n \u201cAs 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,\u201d said Dr. Steffen Tr\u00fcmper.<\/p>\n Not every fossil works<\/p>\n Not every piece of petrified wood can manage this trick. The Kyffh\u00e4user trunks worked because so many separate silica phases stacked up inside them over time.<\/p>\n Some fossils formed in one quick burst, and held only a single moment. At a nearby site with gorgeous cell preservation, the same dating methods came up empty.<\/p>\n What tips the balance is less the grand tectonic setting and more the climate and conditions<\/a> at the time of burial. The right burial turns an ordinary log into a long, readable clock.<\/p>\n The study is published in the journal Scientific Reports<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"In the Kyffh\u00e4user mountains of central Germany, fossilized wood \u2013 in the form of petrified tree trunks \u2013…\n","protected":false},"author":2,"featured_media":580820,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":["post-580819","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/580819","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=580819"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/580819\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/580820"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=580819"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=580819"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=580819"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Close-up](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/08\/fossilized-wood_Kyffhauser-fossil-trunks-closeup_Steffen-Trumper_1s.webp\")
<\/a>Close-up of a sectioned fossilized wood specimen from the Kyffh\u00e4user with a horizontal diameter of approximately 20 centimeters. The white-grey patches are different light and dark quartz generations. Credit: Steffen Tr\u00fcmper. Click image to enlarge.Buried deep and heated<\/p>\n