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Yang et al., Acta Geologica Sinica‐English Edition, 91(2), pp. 749–750 claim that they discovered supercritical hyperpycnal flow deposits in the Early Cretaceous strata on Lingshan Island, East China. We would like to discuss this paper under the following topics: (a) the terminology of "supercritical hyperpycnal flow," (b) hyperpycnal flow deposition, and (c) supercritical flow deposition. Our aim is twofold in that the following debate will help unravel the complexities associated with the controversy around the paleosedimentary environment and sediment dynamic processes of the early Cretaceous deposits on Lingshan Island, in addition to providing an understanding of hyperpycnal flow and supercritical flow deposits. The Beilaishi section deposits on Lingshan Island are more likely storm‐induced tempestites within the lacustrine basin delta front and associated deep lacustrine turbidites. Frequent earthquakes due to tectonic‐magmatic activity are the most likely triggers for lacustrine storms. [ABSTRACT FROM AUTHOR]

The Bengal Fan is a mud-rich, deep-water sediment system. A series of recently discovered biogenic gas reservoirs in the northeastern Bay of Bengal are fine-grained. The Pliocene gas discovered in the study area accumulated in the levee element of a deep-water channel complex identified by high-resolution three-dimensional (3D) seismic interpretation integrated with well logs and sidewall cores (SWC). The thickness and porosity of the levee gas reservoir are of good quality, but the permeability is relatively low owing to the high mud content. The discovery of the levee sandstone indicates various reservoirs in this mud-rich sediment system. Moreover, gas discovery implies that the gravity-flow sediment systems "link" the source rock in the study area. Gas reservoirs were discovered in Pliocene gravity-flow sediment systems, where the palaeo-climate experienced significant changes with a dramatic increase in total organic carbon (TOC) from the Miocene to the Pliocene. TOC-rich pelagic mudstones and deep-water gravity sediments act as source rocks for petroleum systems. Therefore, gravity-flow sediment systems have developed self-accumulating petroleum plays that exhibit enormous potential for exploration. Given the structural framework in the northeastern part of the Bay of Bengal, stratigraphic or structure-stratigraphic traps could have developed in the Pliocene deep-water sediment systems in the Bengal Fan. • Fine-grained deep-water turbidite gas reservoirs in upper Bengal Fan. • Bengal Fan is with Pliocene deep-water sediment systems. • Stratigraphic or structure-stratigraphic traps for exploration. • A close relationship between petroleum and deep-water gravity systems. [ABSTRACT FROM AUTHOR]