#TITLE_ALTERNATIVE#

• Main Author: INSANI (NIM 12007042), HALMI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/13510
• Institution: Institut Teknologi Bandung

The objectives of this study is to understand the geological condition of the area and to arrange the biostratigraphy based on nannoplankton which also include the determination of nannoplankton zonation and reconstruct the depositional environment change by analysing nannoplankton biodiversity and abundance. The study area is included in Rembang-Madura Anticlinorium physiographic zone. The geomorphological units of study area consist of Homoclinal Hills Unit, Homoclinal Valley Unit, and Alluvial Plain Unit. The lithological unit that appeared in this area, from older to younger, are: Packstone Limestone Unit of Bulu Formation, aged Late Miocene (NN9 and/or older), it is deposited in Outer Neritic environment. The next unit is Layered Claystone Unit of Wonocolo Formation, aged Late Miocene (NN10), it is deposited in Upper Bathyal environment. On top of that, Sandstone with Limestone Intercalation Unit of Ledok Formation deposited at Late Miocene – Lower Pliocene (NN10 - NN12) in Outer Neritic environment. Then Marl Unit of Mundu Formation deposited at Lower Pliocene (NN13 - NN17) in Upper to Lower Bathyal environment. Grainstone Limestone Unit of Selorejo Formation deposited afterward at Upper Pliocene – Pleistocene (NN18 – NN20) in Outer Neritic environment. The Massive Claystone Unit of Lidah Formation deposited afterward at Pleistocene (NN21 and/or younger) in Upper Bathyal environment. Then Alluvial Unit lays uncomfortably on top of the Massive Claystone Unit at recent in terrestrial environment. Geological structure which occurred in study area is a strike-slip fault which controlled by relatively N-S force. Based on nannoplankton analysis, the biozonation of study area has divided into seven zonations and the depositional environment change has interpreted with nannoplankton biodiversity – abundance diagram. Nannoplankton population were dominated by Discoaster, Reticulofenestra, and Sphenolithus genera.