Evolution of Late Oligocene - Early Miocene attached and isolated carbonate platforms in a volcanic ridge context (Maldives type), Yadana field, offshore Myanmar

Abstract

This study investigates the stratigraphic evolution of the Late Oligocene-Early Miocene carbonate platforms of the Yadana area (offshore Myanmar). Well data, regional 2D and local 3D seismic surveys allow the identification of three shallow-water carbonate platforms (Yadana, 3DF and 3DE) showing various morphologic and stratigraphic patterns influenced by the presence of a paleohigh. The identification of seven seismic sequences in the Yadana area constrains the stratigraphic evolution in three stages: (1) development of aggrading attached and isolated platforms during the Chattian; (2) a period of platform emersion during the Oligocene-Miocene transition; (3) drowning of the smaller buildup (3DE) associated with km-scale backstepping on the large platforms (3DF and Yadana) during the Aquitanian. The Aquitanian marks the onset of renewed volcanic activity associated with the development of fringing carbonate reefs during the Burdigalian. The rapid (∼6 My) development of these wide (∼5-70 km) and thick (∼300-850 m) carbonate platforms has been mainly controlled by the subsidence. However, the results highlight a strong overprint of eustatic fluctuations on the rates of change in accommodation, and hence on the stratigraphic architecture of the carbonate platforms. Based on an alternative model for the Cenozoic geodynamic evolution of the Yadana area, our results suggest that the platforms developed on a volcanic ridge of hotspot origin located in the Indian Ocean and not on a volcanic arc. Subduction jump processes are interpreted to have played a key role in the demise of all platforms by drastically changing the paleoenvironmental conditions during the Early Miocene, and led to the present-day location of the Yadana Ridge in a back-arc setting. The carbonate platforms from the Yadana area are thus a representative example of the interplay between global mechanisms and local paleoenvironmental parameters on carbonate platform initiation, growth and demise. Highlights ► Three carbonate platforms were developed in the Yadana area during the Late Oligocene-Early Miocene. ► These platforms show attached and isolated settings. ► Eustastic fluctuations affected their stratigraphic architecture. ► They were developed on a volcanic ridge of hotspot origin (Maldives type). ► Local environmental perturbations participated in the platform demise.

Impact of tectonic and volcanism on the Neogene evolution of isolated carbonate platforms (SW Indian Ocean)

“…millions to tens of millions year) evolution of shallow-water carbonate platforms represents a major scientific question and has been the subject of numerous studies over the last decades (e.g. Aubert and Droxler., 1992;Wilson et al, 1998;Wilson, 2000;Schlager, 2005;DiCaprio et al, 2010;Andrieu et al, 2016;Paumard et al, 2017;Pomar et al, 2017;Brandano et al, 2017). The onset, growth and demise of tropical carbonate platforms are controlled by numerous parameters including merely: (1) biota and skeletal grain production, (2) eustacy, (3) tectonics, (4) volcanism and (5), environmental conditions.…”

Hydrocarbon habitat in the Zielin Late Permian isolated carbonate platform, western Poland

“…However, Zielin-like carbonate platforms, which developed on a sulphate platform, and where deposition was controlled by an eroded shield volcano were not discussed. Some similarities to the development of the Zielin isolated carbonate platform can be found in isolated carbonate platforms formed on volcanic cones offshore Myanmar and in the Maldives (Belopolsky and Droxler 2003;Paumard et al 2017), yet these grew directly on topographic highs of the faulted volcanic basement, without any sulphate platforms, and they form a chain of carbonate atolls.…”

Stratigraphy of Architectural Elements of a Buried Monogenetic Volcanic System and Implications for Geoenergy Exploration

“…During lowstand cycles and exposure to freshwater conditions, original tight facies developed high secondary porosity due to leaching of aragonitic material (Wight and Hardian, 1982). In offshore Myanmar, the Yadana field is formed by shallow-water carbonate rocks build-up on a paleo volcanic high, and contains an estimated 7 TCF of gas (Paumard et al, 2017) More recently, world-class accumulations discovered in offshore Brazil suggest that this play works in the pre-salt sequence of both South Atlantic conjugate margins. For example, the Pão de Açúcar field contains estimated values of 700 Mbbl of oil and 3 TCF of gas in carbonates and pillow-basalts located on the top of a volcanic edifice.…”