IJOG : Indonesian Journal on Geoscience
Vol 4, No 3 (2017)

Fracture Characteristics of Mélange Complex Basement in Bantimala Area, South Sulawesi, Indonesia

Sapiie, Benyamin ( Bandung Institute of technology)
Nugraha, Muhamad Aziz ( Bandung Institute of technology)
Wardana, Rizky Kurniawan ( Bandung Institute of technology)
Rifiyanto, Arif ( Bandung Institute of technology)



Article Info

Publish Date
01 Aug 2017

Abstract

DOI: 10.17014/ijog.4.3.121-141A detailed geological mapping and fracture characterization had been performed in Bantimala area, South Sulawesi, Indonesia. The geology of the studied area is composed of pre-Tertiary metamorphic, sedimentary, and igneous rocks which tectonically mixed forming a mélange complex. Located on the southeastern margin of Sundaland, the tectonic strongly influences the fracture occurrences in the studied area. A total of 3,841 fractures comprising shear fractures, extension fractures, veins, and joints have been measured and analyzed. The common fracture orientations are NW - SE, W - E, NNE - SSW, and ENE - WSW trends. Fractures developing in Bantimala have clearly been controlled by lithology and structure position (i.e. fault zones and fold hinge). The orientation of fractures in Bantimala area is different on each lithology, showing that the fracture system was complex. Fracture intensity in schist is higher compared to the other lithologies. The 3D fracture modeling through 3D geocellular modeling was generated using the result from field data measurements and analyses. Discrete Fracture Network (DFN) was built by fifty-one fracture sets that were analyzed from field measurement data. However, the estimation of average fracture porosity from modeling varies significantly depending on lithology. The value of fracture porosity is relatively small, varied from 0.0004 to 0.0029 %. A high fracture porosity number is observed in an area with a significant fracture intensity and most crosscutting of fracture which in turn is controlled by faults and lithology. A mélange complex can have high potential as a basement fractured reservoir target, where fracture distributions and their attributes will vary depending on the lithology as well as local deformation.

Copyrights © 2017






Journal Info

Abbrev

IJOG

Publisher

Subject

Earth & Planetary Sciences

Description

The spirit to improve the journal to be more credible is increasing, and in 2012 it invited earth scientists in East and Southeast Asia as well as some western countries to join the journal for the editor positions in the Indonesia Journal of Geology. This is also to realize our present goal to ...