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大火成岩省下岩石圈地幔的破坏和再生
作者:小柯机器人 发布时间:2023/9/8 13:04:50

英国牛津大学 Simon N. Stephenson 在研究大火成岩省下岩石圈地幔的破坏和再生中取得新进展。2023年9月6日出版的《科学进展》发表了这项成果。

研究人员利用地球化学和地震学观测发现,岩浆作用与薄的岩石圈有关,并揭示了大火成岩省下现代地壳厚度与火山爆发以来的时间之间存在显著的正相关关系。海洋岩石圈增厚至 125 km,而大陆区域达到 190 km以上。研究结果表明,在大火成岩省侵位期间和之后,岩石圈地幔发生了系统性的破坏和随后的再生,且在火山爆发后,大陆进行了重结晶。

这些见解对古老、厚实、化学性质不同的岩石圈根的稳定性、年龄和组成、经济资源的分布,以及导致灾难性环境变化的化学物质的排放都有影响。

据介绍,大火成岩省(LIPs)是由巨大的(即,通常>106 km3)但短暂的岩浆事件形成的,这些事件对全球地球动力学、构造和环境过程具有深远的影响。众所周知,岩石圈结构可以调节地幔熔融,但在如此剧烈的岩浆活动期间和之后,岩石圈结构的演化却很少受到限制。

附:英文原文

Title: Destruction and regrowth of lithospheric mantle beneath large igneous provinces

Author: Simon N. Stephenson, Patrick W. Ball, Fred D. Richards

Issue&Volume: 2023-09-06

Abstract: Large igneous provinces (LIPs) are formed by enormous (i.e., frequently >106 km3) but short-lived magmatic events that have profound effects upon global geodynamic, tectonic, and environmental processes. Lithospheric structure is known to modulate mantle melting, yet its evolution during and after such dramatic periods of magmatism is poorly constrained. Using geochemical and seismological observations, we find that magmatism is associated with thin (i.e., ?80 km) lithosphere and we reveal a striking positive correlation between the thickness of modern-day lithosphere beneath LIPs and time since eruption. Oceanic lithosphere rethickens to 125 km, while continental regions reach >190 km. Our results point to systematic destruction and subsequent regrowth of lithospheric mantle during and after LIP emplacement and recratonization of the continents following eruption. These insights have implications for the stability, age, and composition of ancient, thick, and chemically distinct lithospheric roots, the distribution of economic resources, and emissions of chemical species that force catastrophic environmental change.

DOI: adf6216

Source: https://www.science.org/doi/full/10.1126/sciadv.adf6216

期刊信息
Science Advances:《科学进展》,创刊于2015年。隶属于美国科学促进会,最新IF:14.957