Growth Timing of Southern Field High Carbonates, Central Luconia Province

Abstract

The growth timing of the studied carbonate platform at Central Luconia Province is approximately 4 million years governed by series of third-order sea-level fluctuations and syndepositional tectonics. The prevalent sea-level fluctuations during the Miocene developed a flat-topped limestone interval, capped by a relatively thin dolomitic interval. The first karstification period occurred during the sea-level drop in the Burdigalian stage, over a complex horst and graben setting. The complex surfaces were believed to be predominantly configured by the seafloor expansion of the South China Sea, prior to the carbonate initiation and growth. The second subaerial exposure stage was highlighted as the most prominent karstification period during the Langhian stage, with sporadic distribution of sinkholes, paleocollapse caves, and Uvalas. The third subaerial exposure period is deemed to be a minor karstification stage where a slight fall in the sea level led to buildout and expansion of the carbonate platforms. The final growth horizon is finally drowned during the Serravallian without any further subaerial exposure. A growth timing log is developed based on seismic time slices evidences, sea-level curves, and tectonic information highlighting karstification stages of the carbonate platform.