Fig. 3 | Nature Communications

Fig. 3

From: Global Fe–O isotope correlation reveals magmatic origin of Kiruna-type apatite-iron-oxide ores

Fig. 3

Iron isotope results. Shown is a the distribution of iron isotopes in magnetites from the Kiruna and Grängesberg districts, El Laco, and the Bafq district from this study, and b our data together with available literature data14,45,47,48. Reference fields for common hydrothermal and magmatic magnetites are shown for comparison39,45,46,47,51,69,70. Magnetites from apatite-iron oxide ores show a clear distinction from low-temperature or hydrothermal magnetites and overlap with the layered intrusions and volcanic reference magnetites (i.e. in the magmatic reference field). Data from Wang et al.45 show the effects of a progressive transgression from ortho-magmatic processes to hydrothermal fluid evolution from originally higher to lower δ56Fe values and an originally magmatic fluid may thus evolve into a hydrothermal fluid. One hydrothermal sample from the highly altered, remobilized, and recrystallized Mineville deposit in the USA (δ56Fe = −0.92‰, δ18O = −0.79)14 is not shown for simplification. Ve-Di samples represent vein and disseminated magnetites

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