【摘要】 平坦俯冲是指上覆大陆板块之下大洋板片低角度近水平俯冲(俯冲角度<10°),全球10%的俯冲带为平坦俯冲。前人研究表明,安第斯许多大型-超大型斑岩铜矿和浅成低温热液型金矿与平坦俯冲具有直接的成因联系。同时平坦俯冲对造山作用、地震灾害、构造变形、壳幔相互作用等均具有重要的影响,因此开展平坦俯冲研究具有重要意义。本文主要从以下方面系统总结了平坦俯冲研究成果,包括平坦俯冲的主要表现、地质时期俯冲类型的转变、平坦俯冲的演化过程、平坦俯冲形成的可能机制,分析探讨平坦俯冲与增生型造山带之间可能联系、平坦俯冲与斑岩铜矿床的关系、以及平坦俯冲与洋中脊俯冲(板片窗)的区别,并介绍分析了北美Laramide造山带和华南中生代花岗岩带两个可能的平坦俯冲实例,最后给出平坦俯冲及其成矿效应的几点结论,并对我国今后开展相关研究提出了一些思考与展望,指出中亚造山带尤其是哈萨克斯坦巴尔喀什斑岩铜矿带及邻区和班公湖-怒江斑岩铜矿带构成两个潜在的古平坦俯冲发育区,斑岩铜矿极具潜力。更多还原

【Abstract】 Flat subduction is a type of subduction in which the oceanic crust under overlying plate subducted horizontally or shallowly (usually with the subduction angle<10°), occurring in ~10% of the world’s convergent margins. Many studies indicate that there is genetic relationship between plenty of large-giant porphyry Cu deposits or epithermal Au deposits and flat subduction, especially those deposits developed at Andes. Meanwhile, flat subduction may bring about a large amount of impacts on orogeny, earthquake, crust deformation, crust-mantle interaction. Therefore, research on flat subduction is of great significance. Basing on absorbing and summarizing previous research fruits, this paper gave a comprehensive introduction on flat subduction from the following aspects: the main expression of flat subduction, the transition of subduction type in geologic time, the evolution of flat subduction, the possible mechanisms causing flat subduction. Then we analyzed and discussed the possible connection between flat subduction and accretionary orogeny, and the relationship between flat subduction and porphyry Cu deposits, and also the difference between flat subduction and mid-oceanic ridge subduction (slab window). And then we introduced two possible flat subduction examples, which are Laramide orogeny and Mesozoic granite belt of Southeast China. Finally we summarized several conclusions of flat subduction, and proposed our thoughts and prospects on flat subduction in future, which are Central Asian Orogenic Belt especially the Balkash porphyry copper belt in Kazakhstan and adjacent area and the Bangonghu-Nujiang Au-rich porphyry copper belt in Tibet as the two potential areas of developing ancient flat subduction.更多还原