Kamafugites are 'exotic igneous rocks' with mineralogical and chemical compositions that differ from those observed in common magmas.
Despite their importance, kamafugites are still a poorly constrained topic and they lack a general petrological model due to their variable petrographic, geochemical and isotopic features. A detailed comparison among kamafugites is necessary to obtain a deeper understanding of the processes involved in their petrogenesis and of their strongly metasomatised mantle sources. Therefore, this data publication doesn’t only provide new geochemical and isotopic data from kamafugites, but a comprehensive data compilation for kamafugite samples in the Western branch of the East Africa Rift (WEAR) in Uganda and Democratic Republic of Congo, the Intra-Apennine Province (IAP), as well as for the Alto Paranaiba (APIP) and Goiás (GAP) provinces in Brazil. 97 kamafugite whole-rock data for the WEAR, 42 for IAP and 51 for APIP and GAP have been collected and compared to highlight similarities and differences, aiming to reconstruct their petrogenesis.

The new data in this data publication results from work conducted at Laboratory of Geochronology and Radiogenic Isotope Geochemistry - Pisa1 (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.

The method description only refers to the new isotopic data acquired on Italian and Brazilian kamafugites:

Polished thin sections (28 mm × 48 mm) were prepared at the Dipartimento di Scienze della Terra of the Sapienza University of Rome, after a macroscopic selection. Petrographic analyses have been carried out using a Zeiss Axiophot transmitted polarized light microscope, under plane-polarized light and crossed polars. Micrographs were acquired by means of a digital camera.

New isotopic data (Sr-Nd-Pb) have been measured for five Brazilian kamafugites to provide a coherent dataset. The isotope ratios are corrected for in-situ decay using an age of ~80 Ma. We have also performed seven new boron isotope ratios on Italian samples.

Sample preparation for the isotopic geochemistry was performed in clean rooms, class 100 for Sr and Pb, and class 1000 for Nd, at the Laboratory of Geochronology and Radiogenic Isotope Geochemistry - Pisa1 (IGG-CNR, Italy). Specific resin (Eichrom for Sr; BioRAD AG MP-50 resin for REE and then Eichrom Ln resin for Nd; Bio-Rad 200-400 mesh AG50W-X8 exchange resin for Pb; ion-exchange resin, 20-50 mesh amberlite, and AG 50 W-X8 cation-exchange resin, 200-400 mesh, for B), in a multi-stage process were used to separate the elements of interest from the matrix. Isotopic analyses (Sr-Nd-Pb and B systematics) were conducted at the Laboratory of Geochronology and Radiogenic Isotope Geochemistry - Pisa1 (IGG-CNR, Italy) using a ThermoFisher Neptune Plus MC-ICP-MS. Measurements were carried out on 2% HNO3 solutions, which include around 20-200 ng/g of analyte. Full analytical details can be found in Agostini et al. (2021, 2022).