Depositional and Diagenetic History of the Kerendan Carbonate Platform, Oligocene, Central Kalimantan, Indonesia

Abstract

The Kerendan carbonate platform (Oligocene Berai Limestone) covers a subsurface area measuring approximately 11 by 16 km in the westernmost Kutei Basin, Central Kalimantan. Aggradation of the Kerendan platform occurred during a major Oligocene transgression, and is contemporaneous with aggradation and backstepping of the Barito shelf margin which was located approximately 30 km to the south. The Kerendan platform is approximately 1,000 m thick, and comprises three aggrading seismic sequences identified by the downlap of basinal strata at the platform margin and downlap of transgressive strata within the platform. Carbonate deposition started in the Late Eocene, and ended when the upper limestone sequence drowned and was covered with shale in the Late Oligocene (approximately 28.6 Ma). Three depositional areas can be distinguished in seismic sections: (1) a platform interior (lagoon); (2) a slightly raised platform rim (1-2 km wide); and (3) a basinward-dipping platform margin and slope. The margin of the platform is identified by inflections on the seismic profiles where the relatively flat platform top begins to slope basinward.Depositional models from outcrops combined with core from three Kerendan wells were used to extrapolate depositional facies onto the seismically-defined platform. Platform-interior (lagoon) facies consist largely of fossiliferous wackestones and packstones, and porosities are generally lower than 5%. The platform rim is characterized by interbedded bioclastic wackestones, packstones, grainstones and boundstones, with grainstones increasing toward the platform margin. Porosity preferentially occurs in packstones, grainstones and boundstones. The platform-rim deposits have greater porosity (5-13%) than the platform interior because the platform rim is more grainstone-rich, and because acidic waters compacting out of basinal shales concentrated dissolution near the platform margin. Pore types include vuggy porosity, microporosity within grains, and intercrystalline porosity in dolomite in the upper part of the platform rim. Different pore types have resulted in variable but locally very high permeabilities (greater than 100 mD). Permeabilities decrease with depth as vuggy pores decrease, and microporosity becomes dominant.

Diagenetic history of late Oligocene-early Miocene carbonates in East Sabah, Malaysia

“…The diagenesis of Gomantong Limestone is similar to other Tertiary platforms from neighbouring islands of Borneo such as Tonasa Platform (Sulawesi, Indonesia) [7] which showed limited early diagenesis (marine or meteoric) together with prevalent of dissolution, cementations and compaction that is related to shallow to deeper burial diagenesis [6][7][8]. The types and morphology of cement are discuss in the subsequent sections ( Figure 4A-4F):…”

Seismic characteristics and development of the Xisha carbonate platforms, northern margin of the South China Sea

“…During the Tertiary, extensive tropical shallow-water carbonates, were deposited in the tectonically complex region of the South China Sea (SCS) and adjacent areas (Epting, 1980;Wilson, 2002). The development of Oligocene-Miocene carbonate systems in South-East Asia has been studied from seismic and outcrop data, with special emphasis on third-order depositional sequences (Epting, 1989;Cucci and Clark, 1993;Sun and Esteban, 1994;Mayall et al, 1997;Wilson and Evans, 2002;Grötsch and Mercadier, 1999;Wilson et al, 1999Wilson et al, , 2000Kusumastuti et al, 2002;Saller and Vijaya, 2002;Wilson, 2002;Fournier et al, 2004;Wannier, 2009). The architecture and evolution of carbonate platforms have been determined for most continental margins throughout the world.…”

Upper Pliocene heterozoan assemblage from the Guitar Formation of Car Nicobar Island, India: palaeoecological implications and taphonomic signatures

“…These include the Berai Limestone of SE Kalimantan (Saller and Vijaya 2002), and the Tonasa and Makale Platforms of South Sulawesi in Indonesia (Wilson et al 2000), the Melinau Limestone of north Borneo (Adams 1965), the Wonosari Platform of south Java (Lokier 2000) and the Liuhua Platform of the South China Sea (Erlich et al 1993;Moldovanyi et al 1995). The platform development in most of these cases began during the Palaeogene when corals were limited to remote proportions in many carbonate deposits of SE Asia (Wilson and Rosen 1998), but continued Highest relative abundance of the major skeletal components and various sub-environments are also presented with symbols and colour pattern signatures with sediment accumulation during the Neogene.…”