Differentiating submarine channel-related thin-bedded turbidite facies: Outcrop examples from the Rosario Formation, Mexico

Abstract

Thin-bedded turbidites deposited by sediment gravity flows that spill from submarine channels often contain significant volumes of sand in laterally continuous beds. These can make up over 50% of the channel-belt fill volume, and can thus form commercially important hydrocarbon reservoirs. Thin-bedded turbidites can be deposited in environments that include levees and depositional terraces, which are distinguished on the basis of their external morphology and internal architecture. Levees have a distinctive wedge shaped morphology, thinning away from the channel, and confine both channels (internal levees) and channel

Supercritical flows overspilling from bypass‐dominated submarine channels and the development of overbank bedforms

“…14). This thin-bedded succession has been described previously as representing internal levee deposits (Li et al, 2018) or as flat-topped 'depositional terraces', formed due to limited flow expansion space (Hansen et al, 2015(Hansen et al, , 2017. The presence of trace fossils and foraminifera implies time between flows to allow for colonization and that these deposits do not represent intra-channel sediments, which show restricted fossil assemblages (Callow et al, 2013).…”

“…the deepest part of the channel). That these sinuous channels (maximum preserved width 1,250 m) were able to migrate across a wider channelbelt (~5 km wide) implies availability of significant space for overbank material to accumulate (Kane and Hodgson, 2011;Hansen et al, 2017;Li et al, 2018). That these sinuous channels (maximum preserved width 1,250 m) were able to migrate across a wider channelbelt (~5 km wide) implies availability of significant space for overbank material to accumulate (Kane and Hodgson, 2011;Hansen et al, 2017;Li et al, 2018).…”

“…The facies of the Rosario Formation in the area of Arroyo San Fernando have been described by previous authors Busby-Spera, 1988, 1990; F I G U R E 2 Simplified WNW-ESE cross-section of the San Fernando channel-levee system, modified from Morris and Busby-Spera (1990), Hansen et al (2017) and Li et al (2018). CCS = channel complex set.…”

“…(Continues) wide are present (Kane et al, 2007;Kane and Hodgson, 2011;Hansen et al, 2017). The general palaeocurrent direction is SE, being 45-90° less than those of FA1 ( Figure 5).…”

“…Their sedimentary record typically suggests prolonged periods of erosion, bypass and sediment transfer, which may leave an incomplete record within the channel (Stevenson et al, 2015). A more complete record of channel evolution is commonly found in the overbank deposits that flank them (Kane et al, 2007;Kane and Hodgson, 2011;Hansen et al, 2015Hansen et al, , 2017. Large-scale, fine-grained bedforms adjacent to submarine channels, occurring on levee flanks or depositional terraces, have been documented from seafloor and seismic datasets around the world (see review by Symons et al, 2016).…”