Tidal dynamics and mangrove carbon sequestration during the Oligo-Miocene in the South China Sea

Modern mangroves are among the most carbon-rich biomes on Earth, but their long-term (≥10 6 years) impact on the global carbon cycle is unknown. The extent, productivity and preservation of mangroves are controlled by the interplay of tectonics, global sea level and sedimentation, including tide, wave and fluvial processes. The impact of these processes on mangrove-bearing successions in the Oligo-Miocene of the South China Sea (SCS) is evaluated herein. Palaeogeographic reconstructions, palaeotidal modelling and facies analysis suggest that elevated tidal range and bed shear stress optimized mangrove development along tide-influenced tropical coastlines. Preservation of mangrove organic carbon (OC) was promoted by high tectonic subsidence and fluvial sediment supply. Lithospheric storage of OC in peripheral SCS basins potentially exceeded 4,000 Gt (equivalent to 2,000 p.p.m. of atmospheric CO2). These results highlight the crucial impact of tectonic and oceanographic processes on mangrove OC sequestration within the global carbon cycle on geological timescales

STRUCTURAL CONTROL ON SEDIMENT DISTRIBUTION IN OFFSHORE BRUNEI DARUSSALAM, SOUTH CHINA SEA

ABSTRACT The Neogene clastic intervals, deposited in a shelf to deepwater setting, dominate the Brunei offshore area, South China Sea. Systematic mapping results based on 3D seismic and well data have been used to establish the basin framework. The Brunei offshore area is compartmentalized by faults controlled by gravitational gliding mechanism and tectonics. In general, these processes generated two types of fault systems, northwest dipping, down-to-the-basin faults and southeast dipping, counter-regional faults