<p>Continental rifting is one of the fundamental components in the Wilson cycle, and its comprehensive investigation is essential for understanding the geodynamic mechanisms of plate tectonics. Furthermore, continental rifts host significant mineral and hydrocarbon resources and also preserve valuable records of climatic environmental evolution. This study presents a systematic synthesis of their classification and magmatism after reviewing the research history of continental rifts. The formation and evolution of continental rifts are spatiotemporally associated with magmatic activity. Based on magmatic productivity, rifted margins that develop from successful continental rifts are categorized into different types, including magma-rich and magma-poor, with the intermediate category encompassing margins developed in active continental margin settings. Previous studies and systematically compiled data in this study indicate that distinct magmatic rock assemblages are characteristic of different rift types. Magma-rich rifts and rifted margins typically exhibit bimodal magmatism, including highly alkaline—silica poor alkaline rocks during the early rifting stage, alkalic basalt—trachyandesite—peralkaline rhyolite, transitional basalt and rhyolite during the evolutionary stage, and predominantly tholeiitic basalt during the final stage. Magma-poor rifted margins primarily consist of mafic rocks, including carbonatite and alkaline rocks during the initial rifting stage, followed by alkalic and tholeiitic basalts during the evolutionary stage. The lithospheric mantle in magma-poor rifted margins experienced extensive melt-induced metasomatism, making it an important research target for understanding continental rifting processes and magmatic evolution. In active continental margin rifts, magmatic rocks are dominated by bimodal magmatism, primarily encompassing the entire calc-alkaline suite from basalt to rhyolite, along with minor alkalic basalt. During continental rifting, these magmatic processes effectively weaken the lithosphere, localize deformation, and ultimately facilitate the rifting progression to continental breakup. Further questions meriting attention include: (1) petrogenesis and geodynamics of magmatic rocks in continental rifts; (2) controlling factors for success or failure of continental rifting; (3) the nature of the ocean-continent transition and the process of transitioning from continental rifting to seafloor spreading; (4) controlling factors for the generation of magma-rich versus magma-poor rifted margins; and (5) the impact of continental rifting on climate change. Addressing these questions necessitates integrated approaches combining systematic geological, geochemical, and geophysical investigations of both modern and ancient rift systems with advanced techniques of numerical geodynamic modeling.</p>

Magmatism in continental rifts and rifted margins

期刊论文
发表日期：

2025年8月11日

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Wei Dan,
Qiang Wang,
Gong-Jian Tang,
Xiu-Zheng Zhang

摘要

Continental rifting is one of the fundamental components in the Wilson cycle, and its comprehensive investigation is essential for understanding the geodynamic mechanisms of plate tectonics. Furthermore, continental rifts host significant mineral and hydrocarbon resources and also preserve valuable records of climatic environmental evolution. This study presents a systematic synthesis of their classification and magmatism after reviewing the research history of continental rifts. The formation and evolution of continental rifts are spatiotemporally associated with magmatic activity. Based on magmatic productivity, rifted margins that develop from successful continental rifts are categorized into different types, including magma-rich and magma-poor, with the intermediate category encompassing margins developed in active continental margin settings. Previous studies and systematically compiled data in this study indicate that distinct magmatic rock assemblages are characteristic of different rift types. Magma-rich rifts and rifted margins typically exhibit bimodal magmatism, including highly alkaline—silica poor alkaline rocks during the early rifting stage, alkalic basalt—trachyandesite—peralkaline rhyolite, transitional basalt and rhyolite during the evolutionary stage, and predominantly tholeiitic basalt during the final stage. Magma-poor rifted margins primarily consist of mafic rocks, including carbonatite and alkaline rocks during the initial rifting stage, followed by alkalic and tholeiitic basalts during the evolutionary stage. The lithospheric mantle in magma-poor rifted margins experienced extensive melt-induced metasomatism, making it an important research target for understanding continental rifting processes and magmatic evolution. In active continental margin rifts, magmatic rocks are dominated by bimodal magmatism, primarily encompassing the entire calc-alkaline suite from basalt to rhyolite, along with minor alkalic basalt. During continental rifting, these magmatic processes effectively weaken the lithosphere, localize deformation, and ultimately facilitate the rifting progression to continental breakup. Further questions meriting attention include: (1) petrogenesis and geodynamics of magmatic rocks in continental rifts; (2) controlling factors for success or failure of continental rifting; (3) the nature of the ocean-continent transition and the process of transitioning from continental rifting to seafloor spreading; (4) controlling factors for the generation of magma-rich versus magma-poor rifted margins; and (5) the impact of continental rifting on climate change. Addressing these questions necessitates integrated approaches combining systematic geological, geochemical, and geophysical investigations of both modern and ancient rift systems with advanced techniques of numerical geodynamic modeling.