Assessment of the Geochemical Weathering Indices of Volcanic Soil After the Eruption from Mount Sinabung in 2020

EasyChair Preprint 6664, version 2

Abstract

The weathering process of volcanic material that erupts will release nutrients depending on the type of rock and the level of weathering and then fertilize the soil. The level of weathering of volcanic soils can be measured by calculating the weathering indices to evaluate the stage of soil development, nutrient mobility, and indicate the intensity of chemical weathering in the soil. In this paper, we analyze the total elemental oxides and the degree of weathering of the soil affected by the eruption of Mount Sinabung for 10 years (2010-2020). The samples were taken using the grid sampling method with an interval of 1 km and samples collected as many as 34 samples. In this study, the calculation of the chemical weathering indices includes the Ruxton Ratio and Bases Loss. The results of this study indicates that the average total soil oxides are TiO₂ (0.53-0.90%), MgO (0.74-2.48%), K₂O (1.37-1.88%), P₂O₅ (1.40-2.52%), CaO (2.40-3.59%), Fe₂O₃ (4.82-7.91%), Al₂O₃ (23.09-28.60%), and SiO₂ (53.60-59.28%). The average soil weathering indices calculated from the Ruxton ratio is between 1.90-2.61, Base losses are around 3.318-6.991 and Dessilication indices are 1.452-1.916. Based on the results of the research described above, it can be concluded that the soil affected by the eruption of Mount Sinabung has a moderate level of weathering. The level of weathering from highest to lowest is Southeast>South>East>Northeast.

Keyphrases: Elemental Oxide, Soil nutrient, weathering degree

@booklet{EasyChair:6664,
  author    = {Retno Leodita Lubis and Juniarti Juniarti and Saftia Laila Rajmi and Aldi Nanda Armer and Fakhrijal Rizki Hidayat and Hazi Zulhakim and Novika Yulanda and Ichsan Faishal Syukri and Frisa Irawan Ginting and Dian Fiantis},
  title     = {Assessment of the Geochemical Weathering Indices of Volcanic Soil After the Eruption from Mount Sinabung in 2020},
  howpublished = {EasyChair Preprint 6664},
  year      = {EasyChair, 2021}}