The dehydration and decarbonation processes associated with subduction generate carbon-bearing aqueous fluids, which enable the stabilization of a range of carbonaceous materials under shallow mantle conditions. These reactions provide valuable insights into carbon speciation and recycling in the Earth's deep mantle. Our study focuses on the interactions between aqueous fluids and carbon in the deeper mantle, specifically under conditions corresponding to the upper mantle, mantle transition zone, and lower mantle. Experiments were conducted at pressures ranging from 7 to 25 GPa and temperatures up to 1600°C using the mixture of amphibole and dolomite mixed in different wight proportions. The findings highlight the stability of carbonaceous species such as graphite, methane, diamonds, and secondary carbonates at varying depths. At these conditions, carbon mainly exists in the form of carbonates, which can be reduced to graphite and diamond under specific redox environments in the presence of fluids.