Cobalt distribution and its relationship with bedrocks and cobalt mineralizations in China

Abstract

Cobalt is an essential component of Li-ion batteries. Due to the rapid growth of the electric automobile market in recent years, the global demand for cobalt has surged to an unprecedented level. It is crucial to understand the concentration and distribution of cobalt on a continental scale. The China Geochemical Baselines project, conducted from 2008 to 2012, provides valuable insights into this issue. Catchment sediments/soils were sampled at a density of 1 site per 3000 km2 across most of mainland China, and cobalt concentrations were determined using inductively coupled plasma mass spectrometry. Cobalt concentrations in top sediments/soils (0–25 cm) range from 0.02 μg/g to 77.56 μg/g, with a median value of 10.99 μg/g. In deep sediments/soils (100–150 cm) cobalt concentrations range from 0.91 μg/g to 80.79 μg/g, with a median value of 10.62 μg/g. Cobalt concentrations in top and deep sediments/soils exhibit remarkable similarity, consistently reflecting variations in lithology types of exposed crust. This suggests that the cobalt in catchment sediments/soils is primarily inherited from the rocks. Cobalt distribution patterns in China are consistent with rock types. The conterminous distribution patterns of high background concentrations falling in the Q75-Q85 range are mainly controlled by basic and ultra-basic rocks such as basalts and ophiolites. Sporadic anomalies beyond Q85 strongly correlate with hydrothermal and laterite cobalt deposits, but show weak correlation with magmatic cobalt deposits. This paper provides fundamental continental-scale information for further geological study and mineral exploration.