Evaluation of Geomorphology and Geological Structure on Laterization Process of Ophiolite Complex in Field X, Southeast Sulawesi
Debby Sintia Dewi (a), Novi Triany (a*), Mira Meirawaty (a), Budi Wijaya (a), Ramadhan Adhitama (a), Afiat Anugrahadi (a), Agus Guntoro (a)

(a) Geological Engineering, Faculty of Earth and Energy Technology, Universitas Trisakti
Jl. Kyai Tapa No.1, Grogol, Jakarta Barat, Jakarta, 11440, Indonesia.
*novi.triany[at]trisakti.ac.id

Abstract

The study area is a nickel IUP located in Kolaka Regency, Southeast Sulawesi Province. The study area is part of the ophiolite complex with complex morphological conditions and geological structures. The laterization process in the study area has resulted in a varied distribution of nickel deposits. This study uses layer thickness and Ni content to compare the relationship between geomorphological conditions and geological structures to the laterization process. The research methods used include geomorphological analysis, field observations, and thickness and Ni content distribution analysis based on validated drill data. The results showed that generally, nickel laterite deposits thicken and increase in grade in the undulating hills geomorphological unit with a gentle slope of 4&#8304- - 8&#8304- and partly in the undulating hills unit with a slope of 16&#8304- - 26&#8304-. The morphological factor of slope is the main factor in the laterization and enrichment of Ni content. However, in some hilly areas with steep slopes, the laterization process is strongly influenced by fractures and rising faults in the study area. The presence of ascending faults and intense fractures in the area acts as secondary porosity as a pathway for fluid / meteoric water that will weather the bedrock so that the laterization process can occur properly.

Keywords: Laterization, ophiolite complex, geomorphology, geological structure, Southeast Sulawesi

Topic: Engineering