| Abstrakt: |
Weathering is the change of rock into soil due to hydrospheric and atmospheric processes. This change is characterized by a change in rock characteristics to soil characteristics. The changes that occur are the formation of weathering zones due to changes in the characteristics of rock into soil. The zone formed is the level of weathering intensity from fresh rock to soil as the highest intensity of the weathering process. Changes in rock to soil due to weathering processes can cause landslides, which are characterized by the formation of avalanche slip fields. In this study, the relationship between changes in the weathering chemical index and the determination of the location of the slip plane will be explained in the landslide of Mount Pawinihan, Banjarnegara, Central Java, Indonesia. The method used is the British Standard method. This method can divide the weathering zones based on differences in their physical and chemical characteristics. Then samples from different zones were taken for major oxide calculations by XRF analysis. From the results, the major oxide value is entered into the formula for determining the value of the weathering chemical index. Furthermore, the change in the value of the weathering index will be known. From the results of the value of the chemical weathering index, it is associated with the position of the slip plane, so that the weathering index value that is prone to slip planes will be obtained. Based on the calculation of the chemical index alteration (CIA) zones 3, 4, 5, and 6 are the location of the avalanche slip field. While zone 2 is still included in the safe category against landslides. The conclusion of this study is that zones 3 and 4 are the boundaries for the location of the avalanche field because the CIA value indicates the landslide-prone category. [ABSTRACT FROM AUTHOR] |
