中国科学院地质与地球物理研究所唐冬梅团队近日揭示中亚造山带南部岩浆流的逸出延长了塔里木地幔柱的寿命。这一研究成果于2025年6月2日发表在《地质学》杂志上。

当上升的地幔柱到达小克拉通下方并遇到环境造山伸展时，可能会发生什么？研究组通过考虑塔里木地幔柱和中亚造山带南部的镁铁质-超镁铁质侵入体的情况来探索这种情况。到达地球上较小克拉通之一塔里木克拉通下方的地幔柱持续了300 Ma至270 Ma，峰值分别为290 Ma和278 Ma。与此同时，CAOB处于造山伸展晚期，古亚洲洋向东传播，剪刀状闭合。赋存于镁铁质-超镁铁质侵入体中的镍铜硫化物矿床通常与地幔柱事件有关。然而，越来越多的镍铜硫化物矿床被认为是在相关的造山环境中形成的，例如与南CAOB相关的矿床。 

研究组观察到，镁铁质-超镁铁质侵入体的数量随着距离塔里木克拉通（距离塔里木地幔柱）的距离的增加而减少，这些侵入体的侵位年龄（295-255 Ma，峰值在293 Ma、282 Ma和271 Ma）与塔里木克拉通内塔里木大火成岩省岩浆活动的时间（300-270 Ma）存在7-8百万年的时间滞后。这些不寻常的地质年代学和构造联系表明，地幔柱物质沿着南部CAOB的伸展带向东北逃逸，该伸展带垂直于地幔柱的推断圆形边界，导致造山型镍铜硫化物矿床的形成和深地幔的持续岩浆供应，延长了塔里木地幔柱的寿命。

附：英文原文

Title: Escape of magma flow along the southern Central Asian Orogenic Belt prolonged the lifetime of the Tarim mantle plume

Author: Ke-Zhang Qin, Ben-Xun Su, Franco Pirajno, Richard E. Ernst, Hafida El Bilali, Ya-Jing Mao, Meng-Meng Cui, Jing Wang, Dong-Mei Tang

Issue&Volume: 2025-06-02

Abstract: When an ascending mantle plume arrives beneath a small craton and encounters ambient orogenic extension, what is likely to happen We explored this scenario through considering the case of the Tarim mantle plume and the mafic-ultramafic intrusions in the southern Central Asian Orogenic Belt (CAOB). This mantle plume, which arrived beneath the Tarim craton, one of the smaller cratons on Earth, lasted from 300 Ma to 270 Ma with peaks at 290 Ma and 278 Ma. Synchronously, the CAOB was at the late orogenic extension stage with an eastward-propagating, scissor-like closure of the Paleo-Asian Ocean. Ni-Cu sulfide deposits hosted in mafic-ultramafic intrusions are typically associated with mantle plume events. However, an increasing number of Ni-Cu sulfide deposits are recognized as being emplaced in an associated orogenic setting, such as those associated with the southern CAOB. We observed that the number of mafic-ultramafic intrusions decreases with increasing distance from the Tarim craton (from the Tarim plume), and these intrusions show a 78-m.y. time lag in their emplacement ages (295255 Ma, with peaks at 293 Ma, 282 Ma, and 271 Ma) with respect to the timing of Tarim large igneous province magmatism (300270 Ma) within the Tarim craton. These unusual geochronological and tectonic links suggest that the plume materials were escaping to the northeast along an extensional belt in the southern CAOB, which is perpendicular to the inferred circular boundary of the plume, resulting in the formation of orogenic-style Ni-Cu sulfide deposits and a continuous magma supply from the deep mantle, prolonging the lifetime of the Tarim plume.

DOI: 10.1130/G53464.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G53464.1/654946/Escape-of-magma-flow-along-the-southern-CentralredirectedFrom=fulltext