• Main Author: STEVEN MARBUN, CANTONA
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/70002
• Institution: Institut Teknologi Bandung

The research area is located in Simanindo District, Samosir Regency, North Sumatera. Geographically, the research area is located at UTM coordinates 465000 – 480000 mE and 295300-305000 mN (Zone 47 N). The research area is 109.7 km2. Based on the BMB classification, the research area can be divided into two geomorphological units, Simanindo Homocline Ridge Unit and Simanindo Shore Lake Plain Unit. The research area is in young geomorphic stage. Stratigraphically, the research area can be divided into five non-formal rock units which were formed during Late Pleistocene – Recent, deposited in terrestrial, lacustrine, and fluvial environment. The sequence from old to young strata are Tuff Unit, Sandstone Unit, Siltstone – Sandstone Unit, Diatomite Unit, and Alluvial Deposit Unit. During the deposition of Sandstone Unit and Siltstone – Sandstone Unit, lake’s water level rise and fall occured. Geological structure in the research area is Kampung Kristen Normal Fault and East Simanindo Normal Fault. This structure was formed in Late Pleistocene, after the uplift of the four oldest unit in the research area. Aquifer in the research area is in the Tuff Unit, Sandstone Unit, Siltstone – Sandstone Unit, Diatomite Unit, and Alluvial Deposit Unit. The type of aquifer in the research area is unconfined aquifer with the possibility of the occurrence of confined aquifer within Siltstone – Sandstone Unit. Quality of water in the research area are suitable for drinking according to PERMEN No.492/MENKES/PER/IV/2010 based on pH and TDS value criteria. The pH value ranges from 7.03 – 8.2 while TDS value ranges from 6.9-86.2 mg/L. For retention basin construction requirement, impermeable layer occurrence in the research area is on the Tuff Unit (first rank) and Siltstone – Sandstone Unit (second rank).