Sediment supply control on the delivery of sediments to deep‐lacustrine environment: A case study from Luanping Basin, northern China

Abstract

Deep-water deposits in marine basins have recently received considerable research attention. However, the controls of sediment transported to deep-lacustrine environments are comparatively understudied. In this study, we utilize field-based outcrop data to investigate the variability of sediment distribution and its controlling factors in the Lower Cretaceous synrift Xiguayuan Formation in the Luanping Basin. Two fan-delta systems with variability dominate the measured outcrop sections. At the lithological scale, the ratio of conglomerate to strata in the Xiyuan fan-delta system is 87%, and the average thickness of individual coarse-grained layers is~1 m; the corresponding values in the Caoying fan-delta system are 52% and 0.4 m. In addition, sand-rich gravity-flow deposits are developed in front of the Xiyuan fan delta, whereas mudrich mass transport deposits (i.e., sliding block and slumping debris) are found in front of the Caoying fan delta. At the stratigraphical scale, a delta succession in the Xiyuan section characterized by sand-rich facies from proximal to distal parts is developed in a relatively steep slope setting. In the Caoying section, however, a delta succession characterized by sand-rich facies in the proximal to middle parts is found in addition to a mud-rich distal part developed in a gentle slope setting. Differential sediment supply resulted in significant variation in the sediment distribution pattern. In particular, the grain size of the fan-delta front controls that of the deep-lacustrine gravity-flow deposits fed by them. This study highlights the variability of sediment supply and their control on sediment partitioning in continental rift and marine basins.

Sedimentary architecture of shallow-water fan-delta front in a lacustrine basin: Sangyuan section of Lower Cretaceous Xiguayuan Formation, Luanping Basin, northeast China

“…Lower Cretaceous strata host the Dadianzi and Xiguanyuan formations (Li et al, 2004;Tian et al, 2004). The initial-rift, rift-climax and rift-recession succession have been documented in Xiguayuan Formation, and a complete alluvial fan-lacustrine sequence has been reported, consisting of alluvial fan, fan-delta and lacustrine facies associations (Cope et al, 2010;Dou et al, 2020;Jia et al, 2020).…”

Analysis of the geometric characteristics of clinothems and the relationship with shelf‐edge trajectories of thePlio‐Pleistocenecontinental slope in the Qiongdongnan Basin, South China Sea

“…Their study facilitates better understanding of palaeo‐environmental analyses because clinothems are sensitive to the rate of sediment supply versus the accommodation space (Helland‐Hansen & Hampson, 2009; Pellegrini et al ., 2017b, 2020). Many clinothem studies focus on the internal characteristics and geometric parameters (O'Grady et al ., 2000; Anell et al ., 2014; Anell & Midtkandal, 2017; Beelen et al ., 2019), on palaeogeographical or morphological aspects of the slope and the relationship with sequence stratigraphy (Helland‐Hansen & Hampson, 2009; Olariu & Steel, 2009; Magyar et al ., 2019; Zhuo et al ., 2019), on the response of clinothems to sea‐level fluctuations and sediment supply (Helland‐Hansen & Hampson, 2009; Lin et al ., 2018; Jia et al ., 2020; Trincardi et al ., 2020; Pellegrini et al ., 2021), and on the mechanism that drives the transport of sediment to the basin floor (Plink‐Björklund & Steel, 2002; Steel & Olsen, 2002; Gong et al ., 2016, 2017; Gamberi et al ., 2020; Patruno et al ., 2020).…”