Trigger recognition of Early Cretaceous soft‐sediment deformation structures in a deep‐water slope‐failure system

Abstract

The triggers of soft‐sediment deformation structures (SSDS) that are present in the deep‐water slope‐failure system of the Early Cretaceous Lingshandao Formation on Lingshan Island have been analysed on the basis of SSDS in 5 outcrops. The sediments in these outcrops are interpreted to have been deposited on a near‐shore submarine fan. The inner and middle fans were observed in Yangjiaodong, and the outer fan outcropped in Qiancengya, Dengta, and Chuanchang. The inner and middle fans are characterized by coarse‐grained debrites, turbidites, and rare SSDS, whereas the outer fan by fine‐grained debrites, turbidites, deformed sediments, and abundant SSDS. Based on sedimentary composition, element analysis and palaeo‐geographical indication of SSDS, the source area was supposed to be uplifted Sulu Orogen in an active continental margin. Combination with sedimentary environment, tectonic setting, and the space distribution of different scaled SSDS, seismicity was proposed to be the trigger of larger scaled SSDS, and small‐scale SSDS may be triggered by gravity loading, slump‐derived shear stress, and traction effect. The seismicity may respond to active tectonism and volcanism. Besides, time consistence between the Lingshandao Formation (~131–121 Ma), cooling events, sea‐level change, stable isotope excursion, and palaeo‐seismicity events suggested a catastrophic event, which may be related to two Early‐Cretaceous Anoxic Events (Faraoni Event, ~131 Ma; OAE 1a, ~120 Ma).

Terrestrial expression of the Cretaceous greenhouse regime and its relationship withOAE1a: Evidence from the Jiaolai Basin, eastern China

“…Growing evidence shows that terrestrial ecosystems have also been strongly influenced by the greenhouse regimes and OAEs (Föllmi, 2012; Ge & Zhong, 2018; Hu, Zhao, Yilmaz, & Li, 2012; Mutterlose et al, 2014; Patruno et al, 2015; Robinson, Heimhofer, Hesselbo, & Petrizzo, 2017; Wang et al, 2013; Zhang, Li, Yan, Wang, & Geng, 2020). In China, our understanding of the Cretaceous greenhouse climate and associated OAEs is based mainly on the information revealed from the records of marine successions in the Tibet areas (Hu, Jansa, & Wang, 2008; Li, Wei, Li, & Zhang, 2016), and little has been published on the terrestrial records.…”

“…In eastern China, the Cretaceous fluvio‐lacustrine facies strata are widely distributed, and provide a unique opportunity to test the effects of the mid‐Cretaceous greenhouse regimes and OAEs on the terrestrial ecosystems. Of these, the Jiaolai Basin in Shandong Province, East China (Figure 1) represents a tectonic rift, lake basin in which the Cretaceous lacustrine facies deposits assignable to the Lingshandao Formation were deposited (Ge & Zhong, 2018). Integrated biostratigraphy indicates that the Lingshandao Formation is Aptian (Early Cretaceous) in age and that the black shale unit may represent lithologic responses of the Aptian hothouse climate and associated OAE 1a (~120 Ma), providing a new perspective for further study on the influences of global OAE on the inland lake system in eastern China (Ge & Zhong, 2018; Zhang, Li, Yan, et al, 2020; Zhang, Li, Zhao, Geng, & Yan, 2019).…”

Sedimentary evolution and stratigraphy of the ~765–740 Ma Kansuki-Mwashya platform succession in the Tenke-Fungurume Mining District, Democratic Republic of the Congo

“…The sediments deposited on slopes are usually exposed to gravity instability and overloading and sensitive to seismic shocks, which can produce soft sediment deformation structures (Owen, 2003;Moretti et al, 2001;Ge & Zhong, 2017;Liang et al, 2016). The platform carbonate succession of the Nguba rift-basin was deposited in a tectonically active setting (Lefebvre, 1973;De Waele et al, 2008;Kampunzu et al, 2000;Bull et al, 2011;Mambwe et al, 2019a) as evidenced by seismites and other seismicallyinduced soft sediment deformation structures (see discussion in Mambwe et al, 2019a).…”

Delineation of stratigraphic traps within the basin floor fans of Miocene sedimentary sequences, offshore Indus, Pakistan using inverted acoustic impedance simulations

“…Traditional seismic analysing tools experience band limitation in recognizing the gas‐bearing stratigraphic prospects (Ge & Zhong, 2018; Tayyab & Asim, 2017; Zhong et al, 2020). There are various seismic tools developed for interpretation of the petroleum‐bearing sub‐surface depositional systems.…”