ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Sedimentology, Stratigraphy and Diagenesis

Volume 13 - 2025 | doi: 10.3389/feart.2025.1527186

This article is part of the Research TopicAdvances in Sequence Stratigraphy Interpretation and Their ImplicationsView all 3 articles

Tectono-stratigraphy of the Eocene Zhu-1 Sub-basin in the Pearl River Mouth Basin, China: controls on hydrocarbon source rock variability and implications

Provisionally accepted
Pei  LiuPei Liu*Guangrong  PengGuangrong PengMing  LuoMing LuoYuchen  WangYuchen WangWanlin  XiongWanlin XiongPenglin  SongPenglin SongGuanyun  WuGuanyun Wu
  • Research Institute of Shenzhen Branch of CNOOC China Limited, Shenzhen, China

The final, formatted version of the article will be published soon.

In rift basins, the vertical development and distribution of hydrocarbon source rocks show a makeable variability tightly linking to the tectono-stratigraphic interaction and evolution. This is also highly focused for petroleum industry, which is posing challenges for systematic hydrocarbon accumulation patterns. In the Zhu-1 Sub-basin of the Pearl River Mouth basin, the Eocene rift-related strata are important intervals for potential hydrocarbon exploration. This study analyzes the temporal and spatial attributes caused by tectonic transitions using 3D-seismic, drilling and logging well, and geochemical data., uncovering the impact of tectonic transition on the formation and development of hydrocarbon source rocks in the Eocene rift-related strata in the Zhu-1 Sub-basin. The results indicate that tectonic transitions caused by the HZ movement (~ 43 Ma) have affected the migration of the centers of depocenter and subsidence and drove the formation of two main hydrocarbon source rocks in the upper and lower sections of the Wenchang Formation. The migration of rifting activity has influenced the lateral distribution of high-abundance dark high-quality hydrocarbon source rocks, and expand the range of high-quality hydrocarbon source rocks. The half-graden styles in the different sag change associated with tectonic transitions, and basement uplift and magmatic bottoming reshape the internal stratigraphic structure of the half-graden, leading to the variability of hydrocarbon accumulations. The proposed three hydrocarbon distribution modes, gentle slope dominant, steep-slope dominant and double-slope dominant, were developed in different sags. These models provide important geological theoretical support for the search of potential large-scale hydrocarbon reservoirs in the Pearl River Mouth basin, South China Sea.

Keywords: Tectonic transitions, Hydrocarbon-rich sags, Hydrocarbon source, Petroleum and gas accumulations, Zhu-1 Sub-basin of Pearl River Mouth basin

Received: 13 Nov 2024; Accepted: 14 Apr 2025.

Copyright: © 2025 Liu, Peng, Luo, Wang, Xiong, Song and Wu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Pei Liu, Research Institute of Shenzhen Branch of CNOOC China Limited, Shenzhen, China

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