近日，西澳大利亚地质调查局 R.H. Smithies 及其团队在进行岩石圈构造地球化学填图时发现，该填图否定了伊尔干克拉通太古代地体的增生。相关论文于2023年12月8日发表在《地质学》杂志上。

研究使用新的克拉通地球化学和同位素数据和具独特空间分辨率的图像，显示了 2.73 Ga 前地壳中北东走向至东北东走向的构造。这些趋势与板块构造模型不一致，因为它们持续存在于较年轻的北北西向构造组构中，包括先前被解释为由外来地体增生引起的缝合带。

研究结果表明，北北西向构造具有相当长的走向长度，但其水平位移有限，这些现象对了解区域地质背景来说很重要，但可能是主要的东北东向构造地球动力学上无关紧要的叠加。该团队研究人员认为，这些绿岩省或绿岩带包括在断陷中形成的单个盆地，其位置、大小和方向受基底碎块和区域地壳热伸展之间相互作用的影响。

据研究人员介绍，伊尔干克拉通地体在中太古代至新太古代绿岩带盆地的基底是由距今 3.7 Ga 的地壳碎片组成。

附：英文原文

Title: Geochemical mapping of lithospheric architecture disproves Archean terrane accretion in the Yilgarn craton

Author: R.H. Smithies, K. Gessner, Y. Lu, C.L. Kirkland, T. Ivanic, J.R. Lowrey, D.C. Champion, J. Sapkota, Q. Masurel, N. Thébaud, R. Quentin de Gromard

Issue&Volume: 2023-12-08

Abstract: The basement of Mesoarchean to Neoarchean greenstone basins in the Yilgarn craton is composed of fragments of evolved crust up to 3.7 Ga old. New cratonwide geochemical and isotopic data with unparalleled spatial resolution image a NE- to ENE-trending architecture in pre2.73 Ga crust. These trends cannot be reconciled with plate-tectonic models, as they persist across younger NNW-striking structural fabrics, including a proposed suture previously interpreted to result from exotic terrane accretion. Our results suggest that, in spite of their substantial strike length, the NNW-trending structures have limited horizontal displacement and, although important for understanding regional geology, may be a geodynamically insignificant overprint of the primary ENE-trending architecture. We propose that these greenstone provinces or belts include individual basins formed in rifts with location, size, and orientation influenced by the interaction between basement fragments and regional crustal extension.

DOI: 10.1130/G51707.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51707.1/630521/Geochemical-mapping-of-lithospheric-architecture