DIAGENETIC ALTERATION IN LATE MIOCENE CARBONATE OF TACIPI AREA, SOUTH CELEBES.

PROCEEDINGS PIT IAGI RIAU 2006
The 35^th IAGI Annual Convention and Exhibition
Pekanbaru – Riau, 21 – 22 November 2006

DIAGENETIC ALTERATION IN LATE MIOCENE CARBONATE OF TACIPI AREA, SOUTH CELEBES.

Andri Slamet Subandrio^'

^'Dept. of Geology, Faculty of Earth Science and Mineral Technology, Institut Teknologi Bandung,
Jl. Ganesha No. 10 Bandung 40132, Email : andri@gc.itb.ac.id

ABSTRACT

The Tacipi carbonate platform is a part of Neogene East and West Sengkang Basin that are located in the south part of Sulawesi, precisely in western of Bone city. The limestones of this area, outcropping mainly on the north-south oriented hills such as Temapole, Anadara, Tamping, Lappa, etc., are the best reef example in the Tacipi area, as the reef itself, its debris and detritus can be distinguished in the field. Throughout the ridges and pinnacle in Tacipi field the limestones are predominantly homogenous boundstones on the top and detrital bioclastic packstones with local grainstones, and wackestones at the bottom. Bioclasts are mainly of branching finger-like corals, bivalves and calcareous algae with gastropods, foram and echinoderms. Generally the size of bioclast varies from fine to coarse grained and large coral fragments are common. Calcareous algae and corals in growth position is abundant, embedded in a micritic cements which are partly altered to sparry calcite due freshwater cementation. This reef debris facies occur in the lower part of ridge or pinnacle as inter-reef between the ridges. It is characterized by a changeable facies of rudstones-packstones, wacke stone and mudstones. There are four major reef zonation indentified pacth reef, barrier reef, fore reef and lagoon. The extensive freshwater leaching of fossil fragments and calcareous cement give the preservation of biomouldic and vug pore spaces.