《Nature》河北岩石研究：39.5亿年奥长花岗质片麻岩提示早期俯冲，地幔分离逾43亿年
中国地质科学院 Hangqiang Xie 领衔团队在《Nature》发表研究，在河北省 Shimen 杂岩体发现距今39.5亿年的岩石，是迄今已知最古老的岩石之一。地球年龄估计约45亿年，保存至今的早期岩石极为稀少。研究团队采集了3个样本作详细分析。
团队通过分析岩石内微小锆石晶体定年。分析显示，岩石最初由曾在地球表面或近表面接触过水的物质形成。研究团队提出，这种快速埋藏最可能通过一次短暂俯冲事件实现，提示类似现代板块构造的过程可能在近40亿年前已在地球至少一处发生。
锆石晶体铪同位素分析还提示，从地球地幔分离物质形成新地壳的过程在43亿多年前已经开始。论文题为《Hadean mantle depletion and 3.95-Gyr subduction implied by North China rocks》，数字对象标识为 10.1038/s41586-026-11280-2。
Nature Study of Hebei Rocks: 3.95-Billion-Year Trondhjemitic Gneiss Implies Early Subduction, Mantle Separation Over 4.3 Billion Years Ago
A team led by Hangqiang Xie of the Chinese Academy of Geological Sciences in Beijing reported in Nature the discovery in the Shimen Complex in Hebei province of rocks dating back 3.95 billion years, among the oldest known rocks on Earth. Earth is approximately 4.5 billion years old, and rocks from its earliest days are extremely rare. The team collected three samples for detailed analysis.
The team dated the rocks by analysing tiny zircon crystals trapped inside them. The analysis revealed that the rocks had originally formed from material that had been in contact with water at or near Earth's surface. The researchers proposed that this rapid burial was most likely achieved through a transient subduction event, suggesting that a process similar to modern-day plate tectonics may have been taking place in at least one part of Earth nearly 4 billion years ago.
Analysis of hafnium isotopes in the zircon crystals also suggested that the process of separating material from Earth's mantle to form new crust had begun more than 4.3 billion years ago. The paper is titled 'Hadean mantle depletion and 3.95-Gyr subduction implied by North China rocks', with digital object identifier 10.1038/s41586-026-11280-2.
来源：中国地质科学院
发布：GSM·美国（发布链接）
图片来源：图中是香港大学许士芬地质博物馆展出的中国奥长花岗质片麻岩标本，与本研究分析的同类古老片麻岩属同一岩石类型。来源：Wikimedia Commons, File:HKU 香港大學 Stephen Hui Geological Museum 許士芬地質博物館 the oldest rocks from China TTG Migmatite Taishan complex n old trondhjemitic gneiss Baijiafen Anshan Oct 2016 Lnv.jpg, Chingo Meaopim, CC BY-SA 4.0。
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