Relationships of Magnetic Properties and Heavy Metals Content of Guano in Bat Cave, South Sulawesi, Indonesia

Abstract

Bat Cave is one of the caves with guano deposits in the RammangeRammang karst area, South Sulawesi, Indonesia. The guano deposits can indicate environmental changes in the cave. This study aims to analyze the magnetic properties and correlation between magnetic susceptibility and heavy metal content in guano. Sampling was carried out in Bat Cave, South Sulawesi, Indonesia, and magnetic susceptibility, XRD (mineralogy analysis), and XRF (heavy metal content analysis) were measured. The results showed that the guano sample contained superparamagnetic grains and stable single domain (SP-SSD) measuring <0.05 m with a low magnetic susceptibility value ranging from 7.2 to 147.6 × 10-8 m3/kg. The location of caves in karst areas and climate change affect the magnetic grains. The Pearson correlation coefficient analysis results showed that magnetic susceptibility had a negative correlation with the heavy metal content of Fe. Meanwhile, Fe has a positive correlation with the content of other heavy metals such as Cu, Zr, and Nb. Thus, magnetic susceptibility has the potential as a proxy indicator to detect the presence of heavy metals.