Ore-forming elements and their distribution of nanoparticles in the updraft from the Sanshandao concealed deposit, China

Abstract

The search for concealed ore deposits has increasingly gained attention, due to the gradual depletion of surface resources over time. It is necessary to develop non-traditional geochemical theories and methods to locate concealed deposits. In this study, the morphological characteristics and chemical compositions of particles carried by the updraft of the Sanshandao deposit are observed through transmission electron microscopy. Results presented direct evidence that the composition of nanoparticles in the updraft is affected by the geological background, concealed ore bodies, and oxidation. Cl and Na in the study area are found to be higher than those in other deposits owing to the influence of seawater intrusion. Elements associated with ore-forming are contained in the updraft in the form of nanoparticles, which usually have the same distribution pattern and element assemblage in their particles. Oxygen is found to widely exist in the nanoparticles and matched well with the particle distribution. These combinations of elements from orebodies are not observed in the nanoparticles in the background area. Thus, we considered that nanoparticles associated with the orebodies are formed in the underground orebodies and migrate upward to the surface. Mapping can be used to understand the elemental composition and distribution of the nanoparticles. Based on the composition and distribution of nanoparticles, the elemental characteristics of the underground orebody can be inferred, and the minerals and the distribution range of the concealed orebodies can be predicted.