<p>Carbonate, present in the marine sediments, oceanic crust and seamounts, can be transported into the mantle via subduction, playing a crucial role in deep carbon cycling. However, the characteristics and origin of carbonate in seamounts are rarely studied. Here we focus on the carbonates from the Louisville Seamount chain in the southwestern Pacific Ocean, which were drilled by the IODP Expedition 330. These carbonates are predominantly composed of calcite, and can be divided into vesicle-type, vein-type, cement-type, and cap-type. The vein-type carbonates show high Eu/Eu*, indicating the possible influence of high-temperature hydrothermal fluid. In contrast, the rare earth elemental (with high Y/Ho) and carbon-oxygen isotopic signatures of other types of carbonates are generally similar to those of carbonates found within the oceanic crust, indicating that they are also precipitated from the seawater driven by water-rock interaction. A low-temperature water-rock interaction is suggested since these carbonates are precipitated at a temperature of 4.1–14.5 °C. Due to the high δ¹³C_VPDB and δ¹⁸O_VPDB for these carbonates in the seamount, the recycling of seamount is thus suggested to be a potential candidate for contributing the mantle source of intraplate alkaline basalts in certain regions, such as the Cenozoic basalts in eastern China.</p>