The Distribution of REE in Indonesia

Some experts said that Rare Earth Elements have a special place in today mineral exploration. As stated in the previous article, REE has a great potential for improving battery storage performance. Besides, it also has an unlimited resources. The REE exist in a wide range of rock types like igneous, sedimentary, and metamorphoric rocks. REE deposit in igneous rocks are commonly associated with alkaline and peralkaline rocks. And they can also be formed in carbonitates. It also be enriched in the granitoids through the accumulation of REE-bearing minerals. Such as apatite, allanite, monazite, titanite, and xenotime. According to Zhanheng (2011), REE are reserves in 34 countries. In Asia, fourteen countries have REE deposits, six of them are China, Vietnam, India, Mongolia, Indonesia, and Kazakhstan.

There are three types of main exploration targets of REE deposits in Indonesia. It associated with alkaline-peralkaline igneous (magmatic) rocks, secondary lateritic deposits, and placer monazite (xenotime). For further, granitoids and its wathered crusts are identified as main source of Indonesian REE. A wide distribution of granitoids becomes a sign that more REE deposits will be discovered in Indonesia. The last mapping granitoids location in Indonesia has done by Suwargi et al., 2010 that reported 15 potential locations (figure 1).

Figure 1. Distribution of granitoids in Indonesia (Suwargi et al., 2010).

For further, Indonesian REE is not only associated with the tin belt, but also with granitoids which are distributed from the western most of Sumatera Island to the eastern most of Papua Island. Indoensia also has developed REE from placer deposits, but the REE-bearing minerals called as monazite is categorized as a radiactive mineral by the Mining Law No. 4/2009. As a suggestion, the government need to synchronize the regulation among the sectors, such as the mining law (UU No. 4/2009), energy (UU No. 30/2007), and nuclear (UU No. 10/1997) to develop REE deposits exploration in Indonesia.