Three-stage Mesozoic intracontinental tectonic evolution of South China recorded in an overprinted basin: evidence from stratigraphy and detrital zircon U–Pb dating

Abstract

The NE–NNE-trending Yuan-Ma Basin in central South China, an overprinted basin, is important for understanding the transition in Mesozoic intracontinental deformation in South China from compressional to extensional settings. A detailed sedimentary and structural cross-section across the basin reveals the Upper Triassic – Lower Jurassic black coal-bearing shale, greyish-green sandstone and brick-red claystone, and the Middle Jurassic brick-red sandstone, pebbly sandstone and conglomerate in the eastern segment of the basin. The Lower Cretaceous brick-red coarse sandstone, pebbly sandstone and siltstone occurred in the western and central segments, as well as fault breccia and Lower Cretaceous sandstone at the western margin of the basin. Detrital zircon U–Pb dating by laser ablation inductively coupled plasma mass spectrometry shows that the magmatic and metamorphic zircons yield significant age clusters at 900–700, 500–350 and 300–150 Ma, as well a minor age cluster at 120–100 Ma. Synthesizing the stratigraphic sequences, structures, isotopic dating results and palaeocurrent data, we infer that the Yuan-Ma Basin experienced three evolutionary stages and tectonic settings: (1) during Late Triassic – Early Jurassic time, the Yuan-Ma Basin was related to the diachronous progressive intracontinental deformation as a result of the early Mesozoic Xuefeng intracontinental orogeny in South China; (2) during Middle–Late Jurassic time, the Yuan-Ma Basin was related to intracontinental compression in South China; and (3) during late Early Cretaceous time, the Yuan-Ma Basin was constrained by the intracontinental extension that occurred in eastern China. These three stages, a result of various tectonic regimes, caused the intracontinental deformation that was controlled by the evolution of the continents and their margins.

A Consistently High‐Latitude South China From 820 to 780 Ma: Implications for Exclusion From Rodinia and the Feasibility of Large‐Scale True Polar Wander

“…A bootstrap fold test (Tauxe & Watson, 1994) finds that the tightest grouping of site mean directions is obtained between 68% and 103% unfolding at the 95% confidence level (Figure S1). Since this range of unfolding encompasses 100%, the high‐temperature component passes a fold test, thereby constraining the high‐temperature component to have been acquired prior to Mesozoic folding of the Xiajiang Group (J. Li et al., 2016; H. Ma et al., 2019).…”

“…The Fanjingshan region lies within the Jiangnan orogenic belt that separates the Yangtze and Cathaysia blocks of the South China craton and is characterized by a regional anticline that developed in the Mesozoic (Figure 1b; J. H. Ma et al, 2019).…”

“…Since this range of unfolding encompasses 100%, the high-temperature component passes a fold test, thereby constraining the high-temperature component to have been acquired prior to Mesozoic folding of the Xiajiang Group (J. H. Ma et al, 2019).…”

“…This study presents paleomagnetic and U‐Pb CA‐ID‐TIMS zircon geochronologic data from the Xiajiang Group in the Fanjingshan region of Guizhou province, China (Figure 1a). The Fanjingshan region lies within the Jiangnan orogenic belt that separates the Yangtze and Cathaysia blocks of the South China craton and is characterized by a regional anticline that developed in the Mesozoic (Figure 1b; J. Li et al., 2016; H. Ma et al., 2019). At the core of the anticline is the Fanjingshan Group, dominantly composed of sandstones intruded by intermediate to ultramafic sills (Figure 1b; W. Wang et al., 2014).…”

Magmatic record of the Mesozoic geology of Hainan Island and its implications for the Mesozoic tectonomagmatic evolution of SE China: effects of slab geometry and dynamics in continental tectonics

“…To the west of the Jiagnan orogenic belt is the Middle Triassic Xuefeng Uplift (Fig. 2), which is characterized by NW-directed shortening (Ma et al 2019), NW-SE-oriented mineral lineation and NE-SW-trending folds. The timing of NW-directed thrusting, which involved the Proterozoic basement rocks and the Mesozoic metasedimentary rock sequences, was 243-226 Ma based on monazite dating of sheared micaschists (Chu et al 2012).…”