英国圣安德鲁斯大学S. Fischer团队研究了10亿年前的苏格兰陨石撞击。2025年4月28日出版的《地质学》杂志发表了这项成果。

苏格兰西北部的斯托尔群是欧洲保存最完好的沉积序列之一，包括撞击喷出物矿床Stac Fada段。研究组报告了对冲击锆石颗粒的U-Pb分析，其年龄为990±22 Ma，与影响Stac-Fada段但不影响其边界地层的早期Tonian Pb损失事件一致。他们解释这些数据以记录撞击的时间，撞击发生在之前确定的1177 Ma碱性长石⁴⁰Ar/³⁹Ar年龄后约2亿年。

研究组在Stac-Fada段发现的碱性长石的Rb-Sr年龄约为1735 Ma和1675 Ma，与古元古代花岗岩的碎屑物源一致。其新时代将斯托尔群限制在早托尼阶，并为这些岩石提出了新的新元古代板块构造背景。这些数据修正了英国一些已知最古老的非海洋微化石的年龄，以及它们在陆地真核生物定殖时间中的作用。

附：英文原文

Title: A one-billion-year-old Scottish meteorite impact

Author: C.L. Kirkland, T.M. Erickson, T.E. Johnson, T. Prave, R.A. Strachan, M.L. Daggitt, M.I.H. Hartnady, S.M. Reddy, R.J.M. Taylor, B.V. Ribeiro, K. Rankenburg, U. Kirscher, S. Fischer

Issue&Volume: 2025-04-28

Abstract: The Stoer Group in northwest Scotland is one of the oldest well-preserved sedimentary successions in Europe and includes the Stac Fada Member, an impact ejecta deposit. Here we report U-Pb analyses on shocked zircon grains that yield an age of 990 ± 22 Ma, consistent with an early Tonian Pb-loss event that affected the Stac Fada Member but not its bounding strata. We interpret these data to record the timing of impact, which occurred some 200 m.y. after the previously determined 1177 Ma alkali feldspar 40Ar/39Ar age. The alkali feldspar we find within the Stac Fada Member yields Rb-Sr ages of ca. 1735 Ma and 1675 Ma, consistent with a detrital provenance from Paleoproterozoic granites. Our new age constrains the Stoer Group to the early Tonian and suggests a new Neoproterozoic plate tectonic context for these rocks. These data revise the age of some of the oldest known nonmarine microfossils in the UK and their role for timing the eukaryotic colonization of land.

DOI: 10.1130/G53121.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53121.1/653703/A-one-billion-year-old-Scottish-meteorite-impact