Cenozoic thermal history reconstruction of the Dongpu Sag, Bohai Bay Basin: Insights from apatite fission‐track thermochronology

Abstract

Knowledge of the thermal history of the onshore Dongpu Sag (DPS), Bohai Bay Basin is important for understanding its tectonic development within a broader regional context and for elucidating its poorly studied source‐rock maturation history. To unravel DPS time‐temperature development, apatite fission‐track data were acquired from eight sandstone samples in three deep wells. Thermal history modelling indicates continuous heating during the rifting stage (early Eocene to late Oligocene), followed by cooling attributed to tectonic uplift between ~27 and ~16 Ma, which resulted in the removal of ~1,400 to 1,800 m of section. Reheating occurred during the subsidence stage from middle Miocene until present. Unlike typical passive continental margin basins, the DPS experienced accelerated post‐rifting subsidence from ~5.8 Ma, which was especially marked since ~2.6 Ma. This phase was probably triggered by normal fault reactivation, in combination with a variation in the deep heat flow pattern.

How Did the Late Paleozoic to Early Mesozoic Tectonism Constrain the Carboniferous Stratigraphic Evolution in the Eastern Qaidam Basin, NW China?

“…With the advancement of basin modeling techniques, the analysis of basin tectonic subsidence (uplift) and burial thermal characteristics has become a widely utilized approach in the comprehensive study of superimposed sedimentary basins. This approach has been extensively investigated and reported by the literature [8,10,11,[37][38][39][40][41][42][43]. In this study, we utilized BasinMod ® 2009 software to simulate the tectonic subsidence and burial thermal history of 10 wells in the EQB (well location shown in Figure 1).…”

Molecular Characterization of NSO Compounds and Paleoenvironment Implication for Saline Lacustrine Oil Sands by Positive-Ion Mass Spectrometry Coupled with Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry

“…The Dongpu Depression is based on the Mesozoic and Paleozoic strata, with huge salt-bearing clastic rocks deposited in the Cenozoic (Figure ). , …”

“…The Dongpu Depression is based on the Mesozoic and Paleozoic strata, with huge saltbearing clastic rocks deposited in the Cenozoic (Figure 2). 22,23 The Cenozoic strata developed the Paleogene Shahejie Formation and the Dongying Formation, and the Neogene developed the Guantao Formation and the Minghuazhen Formation (Figure 2). The Quaternary was deposited in the Pingyuan Formation with a total thickness of about 8000 m. Among them, the Shahejie Formation can be divided into Es 4 , Es 3 , Es 2 , and Es 1 ; Es 3 is subdivided into lower, middle, and upper members of Es 3 , with a stratum thickness of about 1500 m (Figure 2).…”