合肥工业大学周涛发团队研究了长江中下游和秦杭成矿带燕山期成矿系统的深部过程与时空演化。这一研究成果发表在2025年3月17日出版的《中国科学：地球科学》杂志上。

长江中下游带和秦杭带是华南中生代成矿带的重要组成部分。然而，关于其深部矿化过程及其背后的动力学机制仍存在争议。通过比较这两个带的地质特征和主要矿化的时间框架，研究组确定了四个不同的燕山期矿化系统：QHMB Cu-Au系统（175-159 Ma）、QHMB W-Cu系统（150-142 Ma）、MLYB Cu-Au（148-135 Ma）系统和MLYB Fe（134-129 Ma）系统。

研究组将成矿岩浆岩的岩石学、矿物学和地球化学特征与深部地球物理数据相结合，研究了岩浆源和深部壳幔相互作用如何影响这些矿床的形成和演化。研究结果表明，这两个带的铜金矿化系统都与来自壳幔混合源（新元古代幼年下地壳+富集岩石圈地幔）的岩浆有关。W-Cu系统与地壳源岩浆（新元古代古地壳）有关，Fe系统与地幔源岩浆（富集岩石圈地幔）在成因上有关。成矿金属（Cu和Au、W和Cu、Fe）分别来源于幼年下地壳、古地壳和富集的岩石圈地幔。MLYB和QHMB的燕山期岩浆和成矿事件都发生在同一构造环境中。

这些事件是由于古太平洋板块从东南向西北俯冲而导致的“新元古代地壳”（预先存在的成矿物质）和“继承边界断层”（预先出现的块体边界）的重新激活造成的。复活的新元古代地壳为成矿提供了必需的金属元素，而复活的块体边界为成矿岩浆的上升提供了途径，并有助于确定矿床的形成位置。因此，该研究提出了一个板内“双重复活”动力学模型来解释两个成矿带的燕山期岩浆作用和成矿作用。

附：英文原文

Title: Linking deep processes and spatio-temporal evolution of the Yanshanian metallogenic systems in the middle-lower Yangtze River and Qin-Hang metallogenic belts

Author: Shiwei WANG, Taofa ZHOU, Yu FAN, Feng YUAN, Dayu ZHANG, Fangyue WANG, Yinfo CHANG

Issue&Volume: 2025/03/17

Abstract: Two metallogenic belts, the middle-lower Yangtze River belt (MLYB) and the Qin-Hang belt (QHMB), are crucial portions of the Mesozoic metallogenic province in South China. However, there are ongoing debates about their deep mineralization processes and the dynamic mechanisms behind them. By comparing the geological characteristics and time frames of major mineralization in these two belts, the present study has identified four distinct Yanshanian mineralization systems: the QHMB Cu-Au system (175–159Ma), the QHMB W-Cu system (150–142Ma), the MLYB Cu-Au (148–135Ma) system, and the MLYB Fe (134–129Ma) system. This study integrates petrological, mineralogical, and geochemical characteristics of ore-forming magmatic rocks with deep geophysical data, and investigates how magma sources and deep crust-mantle interactions influence the formation and evolution of these deposits. The findings reveal that the Cu-Au mineralization systems in both belts are associated with magmas derived from a crust-mantle mixed source (Neoproterozoic juvenile lower crust+enriched lithospheric mantle). The W-Cu system is linked to crustal source magmas (Neoproterozoic ancient crust), and the Fe system is genetically related to mantle-derived magmas (enriched lithospheric mantle). The ore-forming metals (Cu and Au, W and Cu, Fe) were sourced from the juvenile lower crust, ancient crust, and enriched lithospheric mantle, respectively. The Yanshanian magmatic and metallogenic events in both the MLYB and QHMB occurred within the same tectonic setting. These events resulted from the reactivation of the “Neoproterozoic crust” (pre-existing metallogenic materials) and “inherited boundary faults” (pre-existing block boundaries) due to the southeast-to-northwest subduction of the paleo-Pacific plate. The reactivated Neoproterozoic crust provided the essential metal elements for mineralization, while the reactivated block boundaries offered pathways for the ascent of ore-forming magmas and aided in determining the locations of formation of ore deposits. Consequently, this study proposes an intraplate “double reactivation” dynamic model to explain the Yanshanian magmatism and metallogenesis in both metallogenic belts.

DOI: 10.1007/s11430-024-1510-1

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-024-1510-1