Rare earths and other chemical elements determined by neutron activation analysis in new reference USGS materials: carbonatite, nephelinite, syenite, granite, stream sediment and marine shale

Instrumental neutron activation analysis is applied for the determination of 28 chemical element concentrations in seven geological reference materials (USGS), namely CMP-1, COQ-1, NKT-1, SyMP-1, G-3, SSAR-1, and SBC-1. The results are reported contributing to the establishment of new elemental database of novel current available reference materials. Among the reference materials studied, the results obtained for two matrix types of carbonatite are very relevant contributing to establish recommended values for rare earth elements (REE) and other chemical elements. In fact the need of reference materials with very high concentrations of REE is crucial to an accurate chemical analysis of carbonatites, and soils, deposits and sediments with a significant contribution of these rare igneous rocks.