The tectonic transition from rifting to strike-slip in the Liaodong Bay Depression, offshore China

Cenozoic evolution and deformation in the Eastern and Western Depression of the Liaohe Subbasin, Bohai Bay Basin: Insights from seismic data

“…The strike‐slip faults in the Eastern Depression mostly cut into deep strata and are connected to oil sources. These faults were strongly active during the extension period (65–40 Ma) and provided a favourable environment for the development of hydrocarbon source rocks (Figure 13c; Chen et al, 2022; Hsiao et al, 2004; Qi et al, 2008). Moreover, local anticlines caused by strike‐slip deformation (i.e.…”

“…The boundary fault of the Western Depression is a long‐term, active growth fault, and it was conducive to hydrocarbon migration; thus, more hydrocarbons have been discovered in the Western Depression than in the Eastern Depression (Figure 13a). However, if we assume the same source rock conditions, basins that experienced a reactivation of pre‐existing strike‐slip faults may have better exploration potential than pure rift basins (Chen et al, 2022). In recent years, oil and gas exploration in the BBB has confirmed that most of the discovered oilfields are mainly located in the TLFZ (Huang et al, 2018; Zhu et al, 2009).…”

“…Recent investigations based on seismic data interpretation have suggested that the TLFZ began with extensional deformation prior to 40 Ma, followed by right-lateral strike-slip deformation until the present, but the rightlateral strike-slip deformation was the strongest from 40 to 25 Ma (Chen et al, 2022;Hsiao et al, 2004;Hu et al, 2022;Huang et al, 2015Huang et al, , 2018Huang et al, , 2020Jia et al, 2021;Qiu et al, 2018;Wang, Wu et al, 2020). Although controversy on the nature of the TLFZ continues, the TLFZ is beneficial for hydrocarbon accumulation (Gao et al, 2008;Hao et al, 2011;Shan et al, 2005;Teng et al, 2016;Tian et al, 2019) and plays an important role in basin evolution.…”

“…The TLFZ, a typical strike‐slip fault zone, runs through the eastern border of the BBB (Figure 2), which is generally accepted to have originated from the collision of the South China Block and North China Block in the Late Triassic (Chen et al, 2022; Zhu et al, 2009), and the left‐lateral strike‐slip motion of the TLFZ during the Mesozoic was controlled by the subduction of the Izanagi‐Pacific Plate (Chen et al, 2022; Wang et al, 2019; Zhu et al, 2005). From the Cenozoic, the fault slip changed from normal faulting to right‐lateral motion during the Late Palaeogene (Chen et al, 2022; Wang et al, 2019), but the timing and mechanism of the right‐lateral strike‐slip are still controversial. Present‐day earthquakes have suggested that the fault zone is still active (Fu et al, 2004; Hsiao et al, 2004; Huang et al, 2018; Teng et al, 2016).…”

“…Some studies report that the initial time of strike‐slip motion occurred from the Palaeocene to the Early Eocene (Zhang, 2012; Zheng, 2011) or from the Middle to Late Eocene (Hsiao et al, 2004; Huang et al, 2012, 2015, 2018; Mao et al, 2019; Jia et al, 2021; Zhang et al, 2014), while others assert that the transition occurred at the end of the Eocene (Zhang, 2012) or in the Oligocene (Tong et al, 2008). While the mechanism of right‐lateral strike‐slip during the Cenozoic is still controversial, some studies argue that extension and right‐lateral motion are the results of the subduction of the Pacific Plate (Chen et al, 2022; Hsiao et al, 2004), while others state that right‐lateral strike‐slip motion is related to the collision of the Indian and Eurasian Plates (Chen et al, 2022; Wang, Li, et al, 2020).…”