Trace element geochemistry of Amba Dongar carbonatite complex, India: Evidence for fractional crystallization and silicate-carbonate melt immiscibility

摘要: Carbonatites are believed to have crystallized either from mantle-derived primary carbonate magmas or secondary melts derived carbonated silicate through liquid immiscibility residual of fractional crystallization magmas. Although the observed coexistence carbonatites and alkaline rocks in most complexes, their coeval emplacement many, overlapping initial87Sr/86Sr and143Nd/144Nd ratios supportive cogenesis; there been few efforts devise a quantitative method identify magmatic processes. In present study we made an attempt accomplish this by modeling trace element contents Amba Dongar complex, India. Trace data suggest that complex products two separate parental melts. Using available melt-carbonate melt partition coefficients for various elements, carbonatites, tried simulate distribution pattern melt. The results not only support hypothesis silicate-carbonate evolution but also establish procedure test above such complexes.