Sedimentary carbonates could be transported into Earth's mantle by plate subduction, but the ultimate fate of these carbonates remains unclear. Zinc isotopes can allow the tracing of recycled isotopically heavy Zn-rich sedimentary carbonates (δ66Zn up to 0.91‰) within the mantle. This study presents new whole-rock major- and trace-element geochemical and Sr–Nd–Pb–Hf–Zn isotopic data for a complete series of rejuvenated-stage alkaline samples from Kauaʻi, Hawaiʻi. These samples have high MgO contents (MgO >8.6 wt%) and show a wide range of whole-rock geochemical compositions, with lower SiO2 contents, higher alkali element contents, higher CaO/Al2O3 values at a given MgO content, more depleted Sr–Nd–Hf isotopic compositions, and more radiogenic Pb isotopic compositions relative to shield tholeiites. The trace-element compositions of these samples have some similarities to carbonatites, including large ion lithophile element enrichments and K, Pb, and ZrHf depletions. These samples also have systematically higher δ66Zn values (0.34–0.43‰) than shield tholeiites from the Kauaʻi (0.27 ± 0.04‰) and Kīlauea Iki lava lake (0.26–0.30‰) and normal mantle (0.18 ± 0.05‰). Modeling the elemental and isotopic behavior of Zn indicates that the heavy Zn isotopic compositions of these samples reflect the nature of their mantle source rather than any processes associated with mantle melting and fractional crystallization. The low 87Sr/86Sr and heavy Zn isotopic compositions of these alkaline samples can be replicated by mixing depleted mantle with minor amounts of sedimentary Mg‑carbonates (<5%). A decrease in whole-rock SiO2 contents from the alkaline basalts to the melilitites in this region correlates with increases in the geochemical signature of sedimentary carbonate-bearing enriched components (e.g., high δ66Zn and low εNd and εHf values). The correlation between the δ66Zn and 206Pb/204Pb values of the samples is in concert with the role of recycled carbonates that could elevate the U/Pb ratio of mantle component caused by the carbonated melt. This implies that the studied samples formed from magmas derived from a mixed mantle source at least containing depleted peridotite and sedimentary carbonate-bearing components. The addition of recycled sedimentary carbonates may be a key factor for the high δ66Zn and 206Pb/204Pb values of the Kauaʻi rejuvenated-stage lavas. These findings suggest that the subducted sedimentary carbonates could accompany the whole circle of recycling of oceanic slab and experience a recycle deep-to-lower mantle in the Hawaiian mantle plume.