Morphological Identification of Rocks around Ranupani Village, Mount Semeru, Lumajang, East Java

Abstract

Mount Semeru is the highest volcano on Java Island, with its peak of Mahameru at 3.676 meters above sea level (masl). The Semeru volcano is of the Strato type with volcanic-strombolian eruption. This study aims to identify the morphology of rocks found around the mountain in Ranupani Village, Mount Semeru, Lumajang, East Java. Samples were prepared from rocks that had been searched in a limited area from Ranupani Village, Semeru Volcano, then selected, and taken a small portion of the process into powder form, then filtered or sifted. After the sieving process is done, a subtle powder will be obtained. The subtle powder is then ready for XRD testing to find out the identification of the rock morphology. The x-ray diffraction test results were then analyzed qualitatively with the method of search and match. Qualitative analysis of XRD is to determine the crystal structure and composition of the elements contained in these rocks. The sample, phase 1, showed the presence of Barium diiron tetraoxide (Ba Fe2 O4) to form a crystal system orthorhombic. The sample_2 phase shows the presence of Albite (Al Na O8 Si3) to form a crystal system triclinic (anorthic). In sample_3, the phase indicates the presence of Anorthite (Al2 Ca O8 Si2) and the presence of Albite (Al Na O8 Si3) to form a crystal system triclinic (anorthic). The results of rock characteristics with X-ray diffraction show that in sample _2 and sample _3, resulting Silica and Aluminum elements are present. This suggests that the predominant minerals in these samples are likely silicates, such as feldspars and clay minerals, which are rich in silica and aluminum. Further analysis is needed to identify these samples’ specific mineral compositions and proportions. Through Match! 2, from the top of the diffraction pattern (short angle 2 10, 10-60 °), the sample corresponds to the silica and aluminum diffraction patterns.