Diagenesis Of Carbonate Debris Deposits From The Sebuku Block, Makassar Strait, Indonesia

Unravelling the depositional origins and diagenetic alteration of carbonate breccias

“…Although secondary mouldic and vuggy porosity have been partially infilled by blocky to drusy and fibrous calcite and microdolomite, the effects of ?multiple stages of, and in particular late stage burial, dissolution have resulted in high porosity with good connectivity Tanos et al, 2013). These late leaching fluids are thought to be basinal derived, perhaps associated with the early stages of hydrocarbons generation during burial, and are noted elsewhere along the margins of the Berai Platform Saller and Vijaya, 2002;Wilson, 2012;Subekti et al, 2015).…”

“…Unlike Batu Gading, in some of the Ruby Field limestone breccia's (MKS wells) post-brecciation (and possibly pre-brecciation) diagenetic history is characterised by extensive leaching Tanos et al, 2013). Although secondary mouldic and vuggy porosity have been partially infilled by blocky to drusy and fibrous calcite and microdolomite, the effects of ?multiple stages of, and in particular late stage burial, dissolution have resulted in high porosity with good connectivity Tanos et al, 2013).…”

“…The western margin of the Kedango Platform varied considerably along its 30 km plus length with downslope reworking occurring from: (1) distally steepened ramp, (2) bypass to erosional, partially coral fringed margin, and (3) erosional, probably faulted escarpment settings . The Ruby Field breccias of the Berai Limestone underwent erosion and reworking from the platform margin in a fore-reef, toe of slope environment as debris flow fans; this has been inferred from a short transport history evidenced in the clasts, mixing of planktonic foraminifera and mounded seismic geometry Tanos et al, 2013).…”

“…The reworked deposits of the Tonasa Limestone are commonly affected by silica cementation (dissolution-reprecipitation) related to the rapid burial of both siliceous organisms and clasts in slope to deep marine settings (Wilson and Bosence, 1996). The result of mechanical and chemical compaction in deposits from Batu Gading, Tonasa, Kedango and Berai is that of a fitted breccia fabric with pervasive development of circumclast seams and stylolites (Wilson and Bosence, 1996;Pireno et al, 2009;Tanos et al, 2013;Arosi and Wilson, 2015).…”

“…The Tonasa Limestone Formation (Sulawesi: Wilson and Bosence, 1996;Wilson, 1996;2000;Wilson et al, 2000), the Kedango Limestone (Borneo: Wilson et al, 2012; and Berai Limestone (Ruby Field, Makassar Straits: Pireno et al, 2009;Tanos et al, 2013) include submarine carbonate slope breccia deposits that are potentially analogous to the Batu Gading deposits. The breccias present in each of these regional examples show some similarities and also differences in terms of textures, potential origins and diagenesis compared with the Batu Gading breccia, but differ significantly in having their contemporaneous shallow platform deposits still preserved.…”