FN Archimer Export Format PT J TI Quantifying the three-dimensional stratigraphic expression of cyclic steps by integrating seafloor and deep-water outcrop observations BT AF ENGLERT, Rebecca G. HUBBARD, Stephen M. CARTIGNY, Matthieu J. B. CLARE, Michael A. COUTTS, Daniel S. HAGE, Sophie CLARKE, John Hughes JOBE, Zane LINTERN, D. Gwyn STACEY, Cooper VENDETTUOLI, Daniela AS 1:1;2:1;3:2;4:3;5:1;6:1;7:4;8:5;9:6;10:6;11:3,7; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:; C1 Univ Calgary, Dept Geosci, Calgary, AB T2N 1N4, Canada. Univ Durham, Dept Geog, Durham DH1 3LE, England. Natl Oceanog Ctr, Southampton SO14 3ZH, Hants, England. Univ New Hampshire, Ctr Coastal & Ocean Mapping, Durham, NH 03824 USA. Colorado Sch Mines, Chevron Ctr Res Excellence, Dept Geol & Geol Engn, Golden, CO 80401 USA. Geol Survey Canada, Nat Resources Canada, Sidney, BC V8L 4B2, Canada. Univ Southampton, Ocean & Earth Sci, Southampton SO14 3ZH, Hants, England. C2 UNIV CALGARY, CANADA UNIV DURHAM, UK NOC, UK UNIV NEW HAMPSHIRE, USA COLORADO SCH MINES, USA GEOL SURVEY CANADA, CANADA UNIV SOUTHAMPTON, UK IF 3.81 TC 15 UR https://archimer.ifremer.fr/doc/00730/84234/89165.pdf https://archimer.ifremer.fr/doc/00730/84234/89166.docx https://archimer.ifremer.fr/doc/00730/84234/89167.pdf https://archimer.ifremer.fr/doc/00730/84234/89168.zip https://archimer.ifremer.fr/doc/00730/84234/89169.zip https://archimer.ifremer.fr/doc/00730/84234/89170.xlsx LA English DT Article DE ;Cyclic steps;sedimentary structures;submarine channels;supercritical flow;turbidity currents AB Deep-water deposits are important archives of Earth's history including the occurrence of powerful flow events and the transfer of large volumes of terrestrial detritus into the world's oceans. However the interpretation of depositional processes and palaeoflow conditions from the deep-water sedimentary record has been limited due to a lack of direct observations from modern depositional systems. Recent seafloor studies have resulted in novel findings, including the presence of upslope-migrating bedforms such as cyclic steps formed by supercritical turbidity currents that produce distinct depositional signatures. This study builds on process to product relationships for cyclic steps using modern and ancient datasets by providing sedimentological and quantitative, three-dimensional architectural analyses of their deposits, which are required for recognition and palaeoflow interpretations of sedimentary structures in the rock record. Repeat-bathymetric surveys from two modern environments (Squamish prodelta, Canada, and Monterey Canyon, USA) were used to examine the stratigraphic evolution connected with relatively small-scale (average 40 to 55 m wavelengths and 1.5 to 3.0 m wave heights) upslope-migrating bedforms interpreted to be cyclic steps within submarine channels and lobes. These results are integrated to interpret a succession of Late Cretaceous Nanaimo Group deep-water slope deposits exposed on Gabriola Island, Canada. Similar deposit dimensions, facies and architecture are observed in all datasets, which span different turbidite-dominated settings (prodelta, upper submarine canyon and deep-water slope) and timescales (days, years or thousands of years). Bedform deposits are typically tens of metres long/wide, <1 m thick and make up successions of low-angle, backstepping trough-shaped lenses composed of massive sands/sandstones. These results support process-based relationships for these deposits, associated with similar cyclic step bedforms formed by turbidity currents with dense basal layers under low-aggradation conditions. Modern to ancient comparisons reveal the stratigraphic expression of globally prevalent, small-scale, sandy upslope-migrating bedforms on the seafloor, which can be applied to enhance palaeoenvironmental interpretations and understand long-term preservation from ancient deep-water deposits. PY 2021 PD JUL SO Sedimentology SN 0037-0746 PU Wiley VL 68 IS 4 UT 000558669600001 BP 1465 EP 1501 DI 10.1111/sed.12772 ID 84234 ER EF