Cenozoic tectonic evolution of Liaodong dome, Northeast Liaodong Bay, Bohai, offshore China, constraints from seismic stratigraphy, vitrinite reflectance and apatite fission track data

Abstract

The Liaodong dome is a region of localized uplift and deformation within the Liaodong Bay, Bohai, offshore China. 3-D seismic dataset, vitrinite reflectance and apatite fission track data provide an exceptional opportunity to document the evolution of the Liaodong dome which developed coeval with the Tan-Lu strike-slip fault zone with a rift system. The 3-D seismic data demonstrates that the dome formed before the deposition stage of EsM sequence (40Ma), and it uplifted again during or after the depositional stage of Ed sequence (32-24Ma). Apatite fission track and vitrinite reflectance data indicate that the dome experienced two stages of cooling episodes, Paleocene to Early/Middle Eocene (65–40Ma) and Late Oligocene to Late Miocene (30–11.5Ma), usually indicating uplifting. Both the seismic stratigraphy and thermal history analysis show that: 1) the Liaodong dome is part of the Jiaoliao terrane; 2) regional continental rifting climaxed during 65–40Ma, as it did the rift-shoulder uplift of the dome; 3) the reactivation of the Tan-Lu fault caused a second uplift processes of the Liaodong dome during 30–11.5Ma; 4) the Liaodong dome uplifted independently and separated from the Jiaoliao terrane. Our results also suggest that it is important to take uplifting evolution into consideration to target a potential petroleum reservoir.