Reply to the Comment by John J. G. Reijmer on ‘Going with the flow: Experimental simulation of sediment transport from a foraminifera perspective’ by Ash‐Moret al. (2022), Sedimentology, 69, 1231–1251

Comment on ‘Going with the flow: Experimental simulation of sediment transport from a foraminifera perspective’ by Ash‐Mor et al. (2022), Sedimentology, 69, 1231–1251

“…In the last sentence of the abstract Ash-Mor et al (2022) state: "This study shows that the fossil biogenic composition in slope sediments includes valuable information on current velocities, transport dynamics and possible triggers in the geological record." The statement on the use of carbonate biota as information carriers reconfirms the results of an extensive number of studies over the past decades, none of which are cited in Ash-Mor et al (2017, 2022, that specifically used the biogenic composition of carbonate grains to demonstrate, for example: (i) flooding-exposure cycles of carbonate platform production sites on the Bahamas (Haak & Schlager, 1989); (ii) flooding and tectonic uplift processes of Miocene deposits in south-east Spain (Everts, 1991); (iii) flooding-exposure events and carbonate platform progradation patterns for Cretaceous deposits in France (Everts et al, 1999); and (iv) orbital-scaled platform export events of Triassic calci-turbidites and debris flows (Reijmer et al, 1991(Reijmer et al, , 1994. Other studies highlighted the compositional differences in calci-turbidites and calci-debrites when comparing tectonic and sealevel triggered sediment re-deposition events, for example turbidites, debris-flow deposits and mass-transport deposits (MTDs; e.g.…”

“…The features characterizing MTDs as described at the beginning of this paragraph and those known from the literature (e.g. Canals et al, 2004;Lamarche et al, 2008;Shipp et al, 2011;Ogata et al, 2019) differ significantly from those detailing the coarse-grained deposits discussed by Ash-Mor et al (2017, 2022. It appears as if the majority of the thin coarse-grained layers merely represent single gravity flow events that would classify as calci-debrites/calci-turbidites rather than MTDs.…”

“…The Ash-Mor et al (2017,2022) studies detail the sediment composition with high percentages of the coarse fraction >63 lm, 75 to 90% for the slope core MG10P22 and 70 to 98% for the canyon core MG10P27. The MTD layers described by Ash-Mor et al (2017, 2022 are fairly thin with 6 cm and 10 cm for the slope core, and 5 cm, 7 cm (29), 10 cm and 33 cm for the canyon core. The skeletal coarse grains comprise molluscs, corals, echinoids and LBF.…”

“…The (non-)skeletal grains present within eustatic triggered gravity flows link to specific sediment production sites on carbonate platform margins, either interior or margin or slope, as tectonicinduced gravity flows possess a mix of (non-)skeletal grains covering all sediment production sites. For the gravity flow layers discussed by Ash-Mor et al (2017, 2022, a set of LBF (Amphistegina papillosa and Operculina ammonoides as the dominant species, together with Sorites orbiculus, Peneroplis planatus, Heterostegina depressa, but also molluscs, corals and echinoids) are described to be present in both the slope core MG10P22 and the canyon core MG10P27. These species cover depth domains exceeding 100 m (low light domain) for A. papillosa, (e.g.…”

Shape‐dependent settling velocity of skeletal carbonate grains: Implications for calciturbidites

“…Yet, also siliciclastic and mixed carbonate–siliciclastic currents may transport a wide range of densities, as a result of multi‐mineral composition or due to the presence of porous bioclastic grains such as larger benthic foraminifera (e.g. Ash‐Mor et al ., 2022a, although the mechanisms initiating gravity flows remain a point of discussion: Reijmer, 2022; Ash‐Mor et al ., 2022b).…”