Lithium Pegmatites in Africa: A Review

Abstract

Abstract Electrification of transport plays a vital role in the energy transition, which is needed to tackle the pressing challenge of climate change. Lithium is a critical raw material for the batteries that are used to power electric vehicles. Currently, about 60% of the world’s lithium is sourced from rare metal pegmatites, with the top three producing countries (Australia, Chile, China) accounting for more than 80% of global supply. There is limited legal extraction of lithium on the African continent, with Zimbabwe currently being the only country actively mining lithium at large scale, but Africa is host to significant, untapped lithium resources. This paper provides an overview of lithium pegmatites in Africa, describing the key features (e.g., zonation, mineralogy, and paragenesis) of pegmatites from different tectonic settings and of varying ages. It is notable that each of the key orogenic events on the continent has a distinct lithium pegmatite fingerprint. Archaean pegmatites are typically petalite dominated; unzoned spodumene pegmatites are common in the Paleoproterozoic of the West African craton; Mesoproterozoic pegmatites in Central Africa are typically tin-tantalum rich, which is a function of the high degree of albitization observed in many of these pegmatites; and complex zoned pegmatites are more common in the Neoproterozoic to Paleozoic orogens. Many of these pegmatites have a common paragenesis that can be broadly described in four stages (magmatic crystallization, albitization, greisenization, and low-temperature alteration), but there is a need to understand what controls the wider variation in pegmatite type and economic mineral assemblages. The continent of Africa provides an excellent natural lab for placing pegmatites into their broader geologic context in order to develop better mineral deposit models.