1. Introduction
Cenozoic carbonate production, including reefs, occurred
extensively in the tropical shallow-marine areas of Southeast Asia,
a region that was tectonically active throughout the Cenozoic as a
result of the interaction of the Indian-Australian, Eurasian and Pacific plates (Epting, 1989;Wilson et al., 1999, 2000;Wilson, 2002)
(Fig. 1). Carbonate successions in Southeast Asia developed in a
range of tectonic settings, for example, on microcontinental blocks,
around the margins of extensional backarc basins and in forearc
settings (Cucci and Clark, 1993;Sun and Esteban, 1994;Mayall et al.,
1997;Grötsch and Mercadier, 1999;Kusumastuti et al., 2002;Saller
and Vijaya, 2002; Fournier et al., 2004; Wannier, 2009). Strong
Paleogene rifting generated numerous highs in the tectonically
complex South China Sea (SCS) and adjacent areas. Carbonate
platforms developed during the late Paleogene to Neogene on
topographic highs, created by earlier faulting and block tilting.
Especially during the Middle Miocene, aided by favorable climatic
and oceanographic conditions, the platforms were most widespread (Fulthorpe and Schlanger, 1989; Matthews et al., 1997;
Lee and Watkins, 1998; Lee et al., 2001; Bachtel et al., 2004;
Vahrenkamp et al., 2004; Fournier et al., 2005; Fournier and
Borgomano, 2007;Fyhn et al., 2009a, b;Ma et al., 2011).
Previous studies have proposed various interpretations for the
evolution and demise of carbonate platforms in the southwestern
SCS.Epting (1989)proposed that the overall architecture of the
Luconia carbonate platforms in the Zengmu Basin was the result of
four major processes: (i) rates of skeletal carbonate production, (ii)
subsidence rates, (iii) relative sea-level fluctuations and (iv)
terrigenous influx, and that the termination of platforms was
caused by sea-level rise that exceeded the rate of carbonate production. In contrast,Vahrenkamp et al. (2004)held that sea-level
lowering and subaerial exposure terminated the platform growth.
Using a 3D seismic volume and wireline logs,Zampetti et al. (2004,
2005)studied the detailed architecture and evolution of a Miocene
carbonate platform and concluded that platform growth history
included phases of progradation, backstepping and occasional
collapse of platformflanks. The Miocene carbonate platform was
terminated by gradual drowning, showing smooth, concentric
seismic reflections and forming convex mounds on the tops of the
platforms.Fyhn et al. (2009b)suggested that the Phanh Rang
Marine and Petroleum Geology 45 (2013) 55e68
Carbonate Platform, located offshore south Vietnam, initiated
during late Middle Miocene. Following earlier Miocene carbonate
growth continued throughout the late synrift to early postrift
period and terminated during the Pliocene, and was controlled
mainly by structural grain and local and regional tectonics as well
as oceanographic effects, clastic and inorganic nutrient input.
Despite extensive exploration and production of oil and gas in
the Nam Con Son Basin (also referred to as the Wanan Basin by
Chinese) since the late 1980s, especially gas from carbonate reservoirs, little has been reported about the geological evolution of
carbonate platforms within the basin (Matthews et al., 1997). Based
on seismic reflection and well data, we aim to: (1) illustrate the
seismic characteristics of the Nam Con Son carbonate platforms and
associated reefs; (2) reconstruct the growth history of the platforms; (3) evaluate controls on platform evolution
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