近日，加拿大女王大学Christopher J. Spencer团队报道了对劳伦森碎屑锆石“格伦维尔洪水”的再思考：近源，而非大陆河流。相关论文于2025年9月11日发表在《地质学》杂志上。

Laurentia西部广泛存在的中元古代碎屑锆石长期以来被解释为横贯大陆的河流系统从Grenville造山带输送沉积物的证据。该模型认为grenville时代的锆石在新元古代和古生代被带过Laurentia，但最近的同位素和物源数据挑战了这一解释。

研究组表明，直到晚古生代，横贯大陆拱东西部的碎屑锆石年龄分布和Hf同位素组成仍然明显不同，这与长期横贯大陆河流系统的反复沉积混合不一致。相反，劳伦西亚西部的多个斯坦期岩浆构造，包括Llano隆起、Pikes峰岩基和西南劳伦西亚大伊格内奥姆省，提供了可移动的近端锆石构造。此外，梨亚地体、育空北部和以前毗邻的南极火山可能为劳伦西亚西部的沉积记录贡献了碎屑锆石。

泥盆纪后的沉积物再分配可能是由河流、浅海和风成作用的组合完成的，或者是间接的沉积物移动。这些发现表明，格伦维尔时代的锆石在Laurentia分布的原因是晚古生代的作用，而不是元古代的横贯大陆的河流。这个修正后的模型从根本上改变了对深时间沉积物路径的普遍理解，并强调了重新评估长期假设的地球动力学和物源框架的重要性。

附：英文原文

Title: Rethinking the “Grenville Flood” of Laurentian detrital zircon: Proximal sources, not continental rivers

Author: Christopher J. Spencer, Mark E. Holland

Issue&Volume: 2025-09-11

Abstract: The widespread presence of Mesoproterozoic detrital zircon in western Laurentia has long been interpreted as evidence for transcontinental river systems transporting sediment from the Grenville orogen. This model asserts that Grenville-age zircon were carried across Laurentia during the Neoproterozoic and Paleozoic, but recent isotopic and provenance data challenge this interpretation. Here, we show that detrital zircon age distributions and Hf isotopic compositions east and west of the Transcontinental Arch remained distinct until the late Paleozoic, inconsistent with repeated sediment mixing by a long-lived transcontinental river system. Instead, multiple Stenian magmatic sources in western Laurentia, including the Llano Uplift, Pikes Peak batholith, and the Southwestern Laurentia Large Igneous Province, provide plausible proximal sources of zircon. Additionally, the Pearya terrane, the northern Yukon, and formerly adjacent Antarctic crust may have contributed detrital zircon to western Laurentia’s sedimentary record. Post-Devonian sediment redistribution may have been accomplished by a combination of fluvial, shallow marine, and eolian processes, or indirect sediment routing. These findings suggest that late Paleozoic processes, rather than a Proterozoic transcontinental river(s), were responsible for distributing Grenville-age zircon across Laurentia. This revised model fundamentally alters the prevailing understanding of sediment routing in deep time and highlights the importance of reevaluating long-assumed geodynamic and provenance frameworks.

DOI: 10.1130/G53720.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G53720.1/661171/Rethinking-the-Grenville-Flood-of-LaurentianredirectedFrom=fulltext