The fossil records and paleoecological patterns of Southern edge of South Sumatra Basin in Linggapura, Lampung
DG Harbowo(a,b,*)- D Pratama (b)- B Priadi (a,b)- T Julian (b)- DJP Sihombing(b)

a. Institut Teknologi Bandung
Jalan Ganesha 10, Bandung 40132, Indonesia
*danni.gathot[at]itera.ac.id

b. Institut Teknologi Sumatera
Way Hui, Lampung Selatan 35365, Indonesia

Abstract

The South Sumatra Basin is identified as the Paleogene-Neogene sedimentary basin with Mesozoic/older basements in the eastern Barisan Mountains, covering the Jambi, South Sumatra, and Lampung regions. The Lampung region is the southernmost part of the South Sumatra basin. Several South Sumatra Basin constituent formations, such as the Talangakar, Baturaja, and Kasai formations, are apparently present in this area. We investigated this formation through fossil records and described the paleoecological patterns. It is necessary to better comprehend the paleoenvironmental conditions of the edge of the South Sumatra Basin throughout its geological history. It was conducted using measured stratigraphy and fossil observations along the Way Penandingan River in Linggapura, Lampung. The bottom of this area consists of Cretaceous granite. This granite forms the base of the nonconformity sedimentary rocks in this area. The sedimentary rock in this area consists of quartz sandstone to conglomerate with fossilized plant/vegetation remains. The fossils were coalified-carbonized, and some were silicified. The sedimentary rock is similar to the characteristics of the Oligocene Talangakar Formation. Above it are some layers of coral reef limestone containing Miocene reef-lagoonal large foraminifera that is analogous to the Baturaja Formation. Based on the examination of the fossil record and paleoecological patterns, the southern edge of the South Sumatra Basin at Linggapura began to develop in the Late Oligocene to Early Miocene. The ecological conditions in this part of the basin began with the development of terrestrial humid swamps to the fluvial-deltaic environments. It then evolved into arid lagoonal to reef environments, at least 10 million years since the Late Oligocene to Early Miocene.

Keywords: fossil, paleoecology, south sumatra basin, plant fossil, coal, large foraminifera

Topic: Interdisciplinary Geosciences