<![CDATA[Indonesia's tectonic conditions are quite interesting, especially discussing about the boundary conditions of the western and eastern parts of Indonesia's tectonic areas which have very different characteristics. One of the things that results from tectonic activity is magmatism that produces volcanoes. The Sunda arc in the western part of Indonesia is a subduction tectonic zone that produces arc volcanoes, one of the volcanoes that grows there is the Ijen Volcano Complex which is in a very interesting position because it is located at the boundary or transition between the Sundaland part in the west and the crust that thinner in the eastern part of the activity. Its volcanism is also quite interesting because it produces a caldera formed by an explosive eruption. This indicates that there is material under the volcano that contaminates and triggers the eruption. Tectonic activity may also influence the stratigraphic formation of this caldera. The Ijen Complex grows on top of tertiary sedimentary rocks. The magmatism is also affected by the assimilation process between sedimentary rocks and magma that comes from partial melting in the subduction zone. By studying the Ijen Volcano Complex, we can get data that the surface carried by magma rises and erupts so that we can obtain information about what is happening at the bottom beneath the surface there and its tectonic configuration.]]>
