Cathodoluminescence Response of Barite at Room and Liquid Nitrogen Temperatures

Abstract

Rare earth element (REE) abundances in the Elk Creek carbonatite, Nebraska USA, is comparable to ore grade enrichment in carbonatite-hosted REE deposits [1]. Petrographic examination of textures documents a complex history of crystallization, brecciation, recrystallization, oxidation, and near surface alteration. Barite (BaSO 4 ) is present in most units, including REE-enriched zones, such that it may provide important constraints on processes that lead to ore-grade enrichment of carbonatites. Baritecontaining samples from different temperature regimes within the deposit were chosen to determine if the cathodoluminescence (CL) response at room and liquid nitrogen (LN) temperatures provide clues as to the processes by which REEs were enriched within the deposit and possible contributions of REE to the CL response.