The tectonic uplift since the Late Cretaceous and its impact on the preservation of hydrocarbon in southeastern Sichuan Basin, China

Abstract

Tectonic uplift is the most direct manifestation of tectonic activity, and tectonic deformation strength can be quantitatively shown through uplift height and speed. In this study, balanced rebound and oxygen isotope method are adopted to calculate maximum paleoelevation of stratum uplift of southeastern area of Sichuan Basin since Late Cretaceous due to tectonic activities. And based on current surface elevation of the target area, stratum erosion thickness of southeastern Sichuan during this period is calculated, thereby providing technical support for evaluation of the regional oil and gas exploration. Studies have shown that maximum paleoelevation of southeastern Sichuan uplift is gradually increased from NW to SE, which can maximally achieve 3813 m. Denudation quantity from Sichuan Basin to Qiyushang is gradually increased, and region with greater erosion thickness is above 2800 m. Since the Late Cretaceous, southeastern Sichuan stratum uplift makes oil and gas in Dingshan block gradually dissipate. Also, overlying rock unloading results in fault development, early fault activation, and expansion, which further exacerbates destroy of oil and gas reservoir in Dingshan block of southeastern Sichuan, China.Keywords Tectonic uplift Á Paleoelevation Á Erosion Á Southeastern Sichuan Basin Á Oil and gasThe original version of this article was revised: Some of the affiliations were incorrectly indicated. Also the sequence has been changed. Moreover, throughout the article ''Qiyueshan'' has been corrected to ''Qiyushang''.

Thermo‐tectonic history of the Northeast Sichuan Basin, Southwest China, using apatite fission‐track analysis, vitrinite reflectance, and basin modelling: Implications for hydrocarbon prospectivity

“…Regarding that the generation of a large amount of hydrocarbon predated the Late Yanshanian (Pacific subduction) and Himalayan events (Figure 1c), the structural evolution might have resulted in the modification of the primary hydrocarbon accumulation "pools" and creation of secondary pools as in most overseas and Chinese superimposed cratonic hydrocarbon-bearing sedimentary basins (Dai et al, 2008;Green et al, 1995;Liu et al, 2010;Liu et al, 2017; F I G U R E 8 (a) Seismic section along line BB' (shown on the Figure 2b) showing the main structural styles associated with flexural subsidence: thrust nappe, reverse faults, and detachment zones; pop-up structures; and sets of antithetic and synthetic faults; (b) interpreted seismic section along line AA' (Figure 2b) showing the main petroleum traps, which are essentially of structural types, along with the distribution of hydrocarbon accumulations. The T 1 J 4 + 5 formation flayer acted as a regional cap rock for the lower marine petroleum system and as a barrier rock for the upper continental petroleum system.…”

“…The later tectonic uplift phase related to successive continental collisions, including the Indo-sinian, Yanshanian (Pacific subduction), and Himalayan Orogenies, extended from the Cretaceous to the present (Hao et al, 2008;Korsch, Mai, Sun, & Gorter, 1991;Ma et al, 2008). The associated palaeo-thermal regimes have changed accordingly (Liu, Tang, Chen, & Tang, 2017). These variations in structural evolution and thermal regimes were of great significance on the future of petroleum systems and main events (Yong, Fan, Lv, Tang, & Wang, 2018;Zhu, Qiu, Liu, Xiao, & Hu, 2019).…”