Skripsi

ANALISIS PALEOSALINITAS DAN PALEOBATIMETRI BERDASARKAN SEBARAN FORAMINIFERA DAERAH BUMI AGUNG DAN SEKITARNYA KABUPATEN OGAN KOMERING ULU SELATAN PROVINSI SUMATERA SELATAN

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This study was conducted in the Bumi Agung area and its surroundings, Muaradua District, South Ogan Komering Ulu Regency, South Sumatra Province. Geologically, the study area is part of the western part of the South Sumatra Basin, which is a Tertiary-aged back-arc basin consisting of shallow to deep marine sedimentary rocks. The formations exposed at the research site consist of the Baturaja Formation (Tmb) and the Gumai Formation (Tmg). The Baturaja Formation is composed of carbonate limestone deposited in a shallow marine environment, while the Gumai Formation is composed of sandstone and mudstone deposited in a deep marine environment. The main objective of this study is to analyze the relationship between paleosalinity and paleobathymetry based on the distribution of foraminifera in the Baturaja Formation and Gumai Formation. The analysis was conducted to understand the changes in the depositional environment that occurred as a result of marine transgression during the Miocene epoch, as well as to provide an overview of the ancient environmental dynamics in the western part of the South Sumatra Basin. The research methods used included preliminary studies, field observations, laboratory analysis, and studio analysis. Field data collection was carried out through outcrop observation, stratigraphic measurement, and the collection of eight rock samples containing foraminifera fossils. Laboratory analysis includes microscopic morphological identification of foraminifera, taxonomic grouping to genus level, and calculation of the planktonic-benthic ratio (P/B ratio) used to interpret the depth of ancient marine environments (bathymetry). Paleontological analysis results show that eight rock samples yielded 15 planktonic foraminifera species from eight genera, including Orbulina, Globigerina, Globigerinoides, Globorotalia, Cassigerinella, Sphaeroidinella, Catapsydrax, and Globoquadrina. Meanwhile, 25 species of benthic foraminifera were found, originating from 20 genera, including Ammonia, Elphidium, Quinqueloculina, Uvigerina, Pullenia, Cibicides, Lenticulina, Fissurina, and Calcarina. Based on the P/B ratio calculation, the highest value was found at observation location (LP8) at 62.40%, indicating an open sea environment with relatively greater depth (Outer Neritic). The lowest value was obtained at LP4 at 27.97%, reflecting shallow sea conditions (Middle Neritic). A high P/B ratio indicates the dominance of planktonic foraminifera that live suspended in the water column and signifies deep sea conditions with full water circulation, while a low ratio indicates the dominance of benthic foraminifera that live on the seafloor at shallower depths. Interpretation of the results shows that the Baturaja Formation is characterized by low to normal salinity (

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Detail Information

Series Title

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Call Number

T1861882025

Publisher

Indralaya : Prodi Teknik Geologi, Fakultas Teknik Universitas Sriwijaya., 2025

Collation

xiv, 76 hlm.; ilus.; tab.; 29 cm.

Language

Indonesia

ISBN/ISSN

-

Classification

551.07

Content Type

Text

Media Type

unmediated

Carrier Type

other (computer)

Edition

-

Subject(s)

Prodi Teknik Geologi
Ilmu Geologi

Specific Detail Info

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Statement of Responsibility

MI

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