近日，加拿大渥太华大学J. O’Neil团队研究了加拿大努夫亚吉图克绿岩带冥古宙岩浆入侵的证据。相关论文于2025年6月26日发表在《科学》杂志上。

由于冥古宙（距今40.3亿年前）岩石和矿物的稀少，关于地球最早的高峰期仍有许多疑问。加拿大努夫亚吉图克绿岩带（NGB）可能是唯一已知的冥古宙冰冠遗迹，尽管它的年龄在37.5到43亿年之间存在争议。研究组对该带内的镁铁质岩浆岩进行了具体采样和分析，以探讨其岩浆分异的时间。

钐/钕（Sm/Nd）与¹⁴³Nd/¹⁴⁴Nd和¹⁴²/¹⁴⁴Nd比值的相关性分别对应于寿命较长的¹⁴⁷Sm-¹⁴³Nd和寿命较短的¹⁴⁶Sm-¹⁴²Nd系统的年龄，分别为4157±174和4196⁺⁵³_-81万年。现存的和灭绝的放射性成因系统之间的年龄一致，在通过火成岩分异的岩石中，是NGB保存冥古宙岩石的令人信服的证据，打开了一个罕见的窗口，了解地球最早的时代。

附：英文原文

Title: Evidence for Hadean mafic intrusions in the Nuvvuagittuq Greenstone Belt, Canada

Author: C. Sole, J. O’Neil, H. Rizo, J.-L. Paquette, D. Benn, J. Plakholm

Issue&Volume: 2025-06-26

Abstract: Many questions remain regarding Earth’s earliest crust owing to the rarity of Hadean (>4.03 billion-year-old) rocks and minerals. The Nuvvuagittuq Greenstone Belt (NGB) in Canada may be the only known remnant of Hadean crust, although its age is debated, ranging from ≥3.75 to 4.3 billion years old. Mafic intrusions within this belt were specifically sampled and analyzed to investigate the timing of their magmatic differentiation. Correlations between samarium/neodymium (Sm/Nd) and 143Nd/144Nd and 142Nd/144Nd ratios correspond to ages of 4157 ± 174 and 4196+53-81 million years for the long-lived 147Sm-143Nd and the short-lived 146Sm-142Nd systems, respectively. The age agreement between both extant and extinct radiogenic systems, in rocks related through igneous fractionation, is compelling evidence for preservation of Hadean rocks in the NGB, opening a rare window into Earth’s earliest times.

DOI: ads8461

Source: https://www.science.org/doi/10.1126/science.ads8461