GEOLOGI DAN ANALISIS STRUKTUR DAERAH LHOK KEUTAPANG DAN SEKITARNYA, KECAMATAN TANGSE, KABUPATEN PIDIE, PROVINSI ACEH

• Main Author: Rivaldi Prabowo, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/47342
• Institution: Institut Teknologi Bandung

Administratively, research area located in Lhok Keutapang and surrounding areas, Tangse Subdistrict, Pidie Regency, Aceh Province. Geographically, research area is located at 577000 mU?569000 mU and 815000 mT–823000 mT (UTM WGS 1984 46 N Zone) with approximately 64 km2 wide. The purpose of this research is to understand geological condition of research area. Research area is divided into five geomorphological units. These five units are Folding Hills Unit, Jareng-Tangse Vulcanic Hills Unit, Metamorphism Hills Unit, Asan Vulcanic Hills Unit, and Alluvial Plain Unit. Geomorphic stage of research area is mature and the drainage patterns are trellis, dendritic, and parallel. The oldest rock in research area is Slate Unit and Basalt Unit. Protolith of Slate Unit was formed in intervening marginal basin at Late Jurassic?Middle Cretaceous close to Woyla Island Arc and metamorphosed at Late Cretaceous. Basalt Unit formed because vulcanism activity of Woyla Island Arc at Late Jurassic?Middle Cretaceous. In Early Oligocene, Northwest Aceh Basin was formed and become sedimentation basin in research area. In Early Miocene?Middle Miocene, Limestone Unit was deposited in inner neritic?middle neritic environment. In Middle Miocene?Earliest Late Miocene, Siltstone-Claystone Unit was deposited conformably above Limestone Unit in transitional environment. In Late Miocene? Early Pliocene, Barisan Mountain was uplifted and formed localized horst and graben structure. In that graben, Conglomerate-Sandstone Unit was deposited in alluvial fan environment and Sandstone Unit was deposited in braided river environment conformably above Siltstone-Claystone Unit, and these units presumably has interfinger relationship among them. In Late Pliocene?Pleistocene, deformation processes occur because of Sumatra Fault Zone movement outside research area. Folds, strike-slip fault, normal fault, reverse fault, and reactivation of localized graben occur because of this deformation processes. These structural geology follow basic wrench tectonic pattern and can be explained by simple shear deformation model. Erotion process, sedimentation, and deposition of Alluvial Deposit occur in Holocene?Recent.