Numerical modeling of deep oceanic slab dehydration: Implications for the possible origin of far field intra-continental volcanoes in northeastern China

作者：Sheng, Jian^*; Liao, Jie; Gerya, Taras

来源：Journal of Asian Earth Sciences, 2016, 117: 328-336.

DOI：10.1016/j.jseaes.2015.12.022

• Deep slab dehydration
• Hydration-induced melting
• Intra-continental volcanoes
• Numerical modeling

Intra-continental volcanoes have different origins compared to arc volcanoes, and several conflicting geodynamic mechanisms of intra-continental magmatism have been proposed, which require quantitative testing. In this paper, we investigate numerically possible influences of deep subducted slab dehydration processes for the development of intra-continental volcanoes distributed in northeastern China. We employ 2D thermo-mechanical numerical models to investigate the complex dynamics of long-term subduction process, including slab interaction with mantle transition zone, deep oceanic plate dehydration, trench rollback, and back-arc extension. Our experiments show systematically that water can be transported to the transition zone by stagnant slabs hydrating the overlaying deep asthenospheric mantle. Positively buoyant partially molten hydrous plumes arising from the hydrated area formed atop the slabs can propagate upwards and form partially molten mantle regions under the far field continental plate. Our numerical models thus suggest that the development of widely distributed intra-continental volcanism in northeastern China could be related to the rising of multiple relatively small hydrous plumes triggered by stagnant paleo-Pacific slab dehydration in the transition zone.

• 出版日期2016-3-1
• 单位中国地震局; 吉林省地震局; 南京工业大学