Fonnesu, M, Patacci, M orcid.org/0000-0003-1675-4643, Haughton, PDW et al. (2 more authors) (2016) Hybrid Event Beds Generated By Local Substrate Delamination On A Confined-Basin Floor. Journal of Sedimentary Research, 86 (8). pp. 929-943. ISSN 1527-1404
Abstract
The outer parts of deep-water fans, and the basin plains into which they pass, are often described as areas where erosion is negligible and turbidite systems have net aggradation. Nevertheless sedimentological and stratigraphic analysis of outer fan lobe and confined basin plain deposits in Cretaceous-Paleocene Gottero Sandstone (NW of Italy) has revealed extensive but cryptic bedding-parallel substrate-delamination features at the base of many sheet-like event beds. These comprise a variety of shallow but wide scour structures showing evidence of lateral expansion by sand-injection. The scours commonly occur at the base of beds made up of a basal clean sandstone overlain by argillaceous sandstone containing abundant mudstone clasts and locally large substrate rafts (up to 20 meters long). These strata are interpreted as a type of hybrid event bed. Field observations suggest that mud-clast entrainment occurred by delamination at the base of dense sandy flows. The large rafts, in some cases only partly detached, were incorporated in the flows locally and then carried for short distances (100s m to a few km) before partly disaggregating and undergoing deformation due to internal shearing. The development of such features may be common in flat and/or confined basin settings where high-volume flows interact with a cohesive and well layered substrate (e.g. muddy outer fans or confined or ponded basins with thick mudstone caps). Delamination is therefore suggested as an alternative mechanism leading to the formation of hybrid event beds following local substrate entrainment on the basin floor as opposed to on more remote slopes and at channel-lobe transition zones.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016, SEPM (Society for Sedimentary Geology). This is an author produced version of a paper published in Journal of Sedimentary Research. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | turbidites, hybrid event beds, substrate delamination, scours, basin plain, entrainment |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Earth Surface Science Institute (ESSI) (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Jun 2016 10:08 |
Last Modified: | 31 Jan 2019 11:30 |
Published Version: | https://dx.doi.org/10.2110/jsr.2016.58 |
Status: | Published |
Publisher: | Society for Sedimentary Geology |
Identification Number: | 10.2110/jsr.2016.58 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:100431 |