Reply to Comment on “Baddeleyite U-Pb age and Hf isotopes, and constraints on genesis of the Panzhihua carbonatite in SW China” by Arndt, Ganino and Li

Abstract

The calcareous rocks adjacent to the Panzhihua intrusion were considered as carbonatite rather than marbles/skarns based on detailed field mapping and profile survey. Arndt et al. (2023) presented data and figures to compare the difference of trace elements of carbonatite between Panzhihua (they called “dolomite” or “marble”) and other areas in the world and maintained their genesis interpretation. However, carbonatite and carbonate can’t be well distinguished by the trace elements and Hf isotope, because that only approximately 20 % occurrences of global carbonatites contain high contents of rare earth elements. The mineral composition, major element, Ni (avg. 1011.91 ppm), Cr (avg. 1762.73 ppm), and ∑PGE (avg. 12.95 ppm) contents of the dark ultramafic enclaves hosted in the white calcareous rocks indicate that they are mantle-derived xenoliths rather than dolerite (or gabbro and diabase) or metamorphosed peridotite. The large number of mantle xenoliths also implies that their surrounding rock is more likely to be mantle-derived magmatic rock (i.e. carbonatite) rather than skarn. Furthermore, from melanocratic xenolith core and leucocratic surrounding carbonatite to middle zebra rocks, only physical rather than chemical change (i.e. contact metamorphism) happened due to without obvious mineral composition variation.