Utami, Dwi Amanda
Research Center for Geotechnology – Indonesia Institute of Sciences (LIPI) Komplek LIPI Gd. 70, Jalan Sangkuriang, Bandung 40135

Published : 2 Documents

Found 2 Documents

Diagenetic Screening in Porites Fossil Corals from South Pagai, Kendari, and Banten Bay, Indonesia Utami, Dwi Amanda; Cahyarini, Sri Yudawati
Journal of Engineering and Technological Sciences Vol 49, No 1 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (996.827 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.1.1


Fossil corals are commonly used in paleoclimate studies to get records of climate parameters throughout the Holocene and beyond. Diagenesis is known as an important error source in paleoclimate reconstruction. The aim of this research was to provide a comprehensive diagenetic investigation involving 2D-XRD, petrographic analysis, and scanning electron microscopy (SEM) of Porites spp fossil samples from South Pagai, Kendari and Banten Bay, Indonesia as a starting point for further climate studies using coral proxies. This research focused on samples with around 1% calcite content, a level that can create misinterpretation of geochemical proxies. The results indicate that the samples from Banten Bay and South Pagai are well preserved and reliable for paleoclimate study. Only Sample BG1 is not recommended for further use in geochemical proxy analysis due to intensive diagenesis. 2D-XRD allows calcite screening without destroying the coral sample and assists in defining alternative sampling transects. Secondary aragonite and dissolution cannot be identified with 2D-XRD, therefore diagenetic screening should be combined with petrographic and SEM analysis in any areas presumed to have diagenetic textures.
Sedimentary Environment of a Modern Carbonate Platform of Karimunjawa Islands, Central Java Solihuddin, Tubagus; Utami, Dwi Amanda; Salim, Hadiwijaya Lesmana; Prihantono, Joko
Indonesian Journal on Geoscience Vol 6, No 1 (2019)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4221.051 KB) | DOI: 10.17014/ijog.6.1.57-72


DOI: 10.17014/ijog.6.1.57-72Sitting in a biodiversity “hotspot” of the mid-Sunda Shelf region, Karimunjawa Islands have currently been the priority for marine biodiversity conservation. Knowledge of surface sediments on modern carbonate platform is one of essential information to support conservation policies, but such has received little attention from reef researchers. This study describes the sediment characteristics of the selected modern carbonate platforms of Karimunjawa Islands through integrated sediments and satellite data analysis. Textural group of sediments indicates that moderate to poorly sorted gravelly sands are dominant with no grading pattern concerning geomorphological and habitat succession from landward to seaward. Sediment compositions are predominantly bioclastic components, comprising coral and mollusks as the highest and the second highest estimated order of abundance. The reworked grains and rock fragments, although present, are not volumentary abundant. The carbonate sedimentary facies is primarily composed of mud-lean packstone with additional proportion of grainstone and packstone. There are only slight distinct sedimentological characteristics for all benthic habitats as shown by the principal component analysis revealing overlap relationship between sediment parameters and benthic habitats. The study provides the first characterization of sediments which operate on the modern carbonate platform of Karimunjawa Islands along with their controlling factors and specialized nature.