Petrography Study of Metasedimentary Rocks from Eastern Part of Seram Island, Indonesia: Insight into the Paleoclimate Condition
Desi Kumala Isnani (a*), Afrilita (a), Muhammad Zakiy Yusrizal (b), Dian Purnami Handayani (c), Salsa Ine Safira (a), Dhani Ariyanto (a), Bima Wicaksana (a), Muhammad Luthfi (b), Sugeng Sapto Surjono (d), I Wayan Warmada (d)

a) Geological Engineering Department, Universitas Pembangunan Nasional Veteran Yogyakarta
*rr.desi[at]upnyk.ac.id
b)Petroleum Engineering Department, Universitas Pembangunan Nasional Veteran Yogyakarta
c) Chemical Engineering Department, Universitas Pembangunan Nasional Veteran Yogyakarta
Jalan Padjajaran, Yogyakarta 55283, Indonesia
d) Geological Engineering Department, Universitas Gadjah Mada
Jalan Grafika 2, Yogyakarta 55281, Indonesia

Abstract

Analyzing metasedimentary rocks provides critical insights into Earth^s climatic history. This research focuses on petrographic examination of samples from eastern Seram Island, Indonesia. Detailed thin-section analysis, mineral composition, and textures aim to reconstruct paleoclimate conditions during deposition and metamorphism. The analysis reveals distinct mineral assemblages and textures indicative of specific pressure-temperature conditions. Samples are classified as lithic wacke, lithic arenite, and sublitharenite. Quartz (Q) ranges from 35.48% to 76.09%, lithic fragments (L) from 6.52% to 53.22%, and feldspar (F) from 2.81% to 18.33%. Plotting the detrital modes on ternary diagrams indicates predominantly humid and tropical paleoclimate conditions, suggested by high quartz content and intense chemical weathering. The presence of lithic fragments suggests increased sedimentary input from active orogenic sources.This study highlights the importance of metasedimentary rocks as archives of paleoclimatic information, contributing to understanding Earth^s climatic evolution.

Keywords: Metasedimentary rocks- Petrographic examination- Seram Island- Paleoclimate

Topic: Engineering