ABSTRACT
About 90% of the earth's carbon is distributed in the deep part of the earth, and the lithospheric carbon pool occupies most of 90%. Although the carbon content of the lithospheric carbon pool is the highest, the research methods are not mature enough. The stability of methods such as mineral carbon sinks, soil carbon sinks, and karst carbon sinks, as well as the future development direction, are issues that need to be solved urgently. The subduction zone is the link between the earth's surface and the earth's deep system, and it is also an essential place for material exchange between the earth's surface and the earth's deep system. Combined with previous studies, this article briefly summarizes the deep carbon cycle process and restrictive factors in the subduction zone, as well as the decarburization mechanism and carbon sequestration process of the subduction zone. The decarburization mechanism of the subduction zone mainly includes metamorphic reaction decarburization, fluid dissolution decarburization, melting action decarburization, and redox reaction decarburization, The carbon in the subduction zone will not all leave the subduction zone, and part of it will follow the subduction zone into the deep part of the earth, which is the process of carbon sequestration. The deep carbon cycle in the subduction zone is a small step to promote a more mature geological carbon sink, which needs to be further studied.
