Geoheritage Potential of Non-Volcanic Hot Springs in Bangka Island: Implications for Geotourism Activities

Abstract

Natural hot springs are important for various domestic purposes, health treatments, recreational bathing as well as settings for socio-cultural and traditional functions for thousands of years. However, most people are not aware and familiar with the key geological processes of these hot springs. There are three natural hot springs were discovered in the Bangka Island, while the origin and source of these hot springs are still poorly understood. This study provides the water characteristics of those springs and discusses of their origin by considering geological setting, as well as identified these hot springs as geoheritage sites potential. The surface temperatures of thermal springs range from 46 - 49° C, and the pH values ranges from 5.0 to 6.0. The hydro geochemical characteristic of hot springs is divided into two types, mature water and peripheral water. The anion composition (Cl-SO4-HCO3) obtained from water samples of the Permis Hot Spring contains high Cl, indicates as mature water type, and unrelated to recent volcanism. On the other hand, a water sample from the Nyelanding Hot Spring is relatively high HCO3
which indicate as pheripheral water type, and far from the primary source. The Na-K-Mg ternary diagram reveals that water samples of the Permis hot spring is partial equilibrium water type with high Na and Cl compositions, while the Nyelanding one is immature water type characterised by high Mg content. Radiogenic granitic host rock represents the main heat source for both non volcanic hot springs in Bangka Islands. The heat is derived from deep-shallow circulation of meteoric water through fractures that cut into the granitic plutons. These hot springs are unique and show special features that play an important role in understanding of the dynamic of the Earth. These hot springs also have some significant geoheritage values, such as scientific, aesthetic, and recreational. Therefore, these hot springs have the potential to be properly conserved, managed and developed geoheritage sites and utilised for a sustainable geotourism development in Bangka Island.

Keyword: Non-volcanic hot springs, geoheritage, geotourism, Bangka Island