Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada
High‐quality subsurface data provide new insights into the formation of Oak Ridges Moraine (ORM), an ~80 km 3 sequence of stratified meltwater deposits resting >200 m above adjacent Lake Ontario. The ORM sedimentary succession comprises a three‐part regional architecture: (i) ~north–south channel...
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crwiley:10.1111/bor.12612 2024-06-02T08:08:21+00:00 Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada Sharpe, David R. Russell, Hazen A. J. 2023 http://dx.doi.org/10.1111/bor.12612 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12612 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12612 en eng Wiley http://creativecommons.org/licenses/by-nc-nd/4.0/ Boreas volume 52, issue 3, page 341-380 ISSN 0300-9483 1502-3885 journal-article 2023 crwiley https://doi.org/10.1111/bor.12612 2024-05-03T10:41:17Z High‐quality subsurface data provide new insights into the formation of Oak Ridges Moraine (ORM), an ~80 km 3 sequence of stratified meltwater deposits resting >200 m above adjacent Lake Ontario. The ORM sedimentary succession comprises a three‐part regional architecture: (i) ~north–south channel sand–gravel; (ii) channel‐capping rhythmites; and (iii) east–west ridge sediments. The ORM depositional sequence overlies a regional unconformity with a cross‐cutting channel network resulting from ~north–south meltwater floods that transitioned progressively (falling stage) from a ~NNE to ENE flow direction (parallels Lake Ontario depression). Seismic profiles delineate the channels and channel fill characteristics of bank‐to‐bank channel sedimentation of thick gradational gravel–sand–mud sequences. Channel‐capping mud (~100–236 rhythmites) within multiple channels beneath the ORM landform mark a widespread interval of low‐energy, seasonally controlled subglacial pond deposition. During this quiescent period ice‐sheet thickness adjusted to flood‐induced stretching/thinning and re‐profiled slopes. New ice gradients led to east–west flow and deposition of the overlying third element, a sequence of high‐energy confined esker–fan sediments along ORM ridge. Close, sequential timing (~329 varve years) of channel, basin and ridge‐forming architectural elements supports naming this assemblage the ORM formation. Proposed ORM floods are analogous to Icelandic jökulhlaups based on the size, geometry and sedimentology. The observed rhythmite interval between flood events represents a short period (~236 years) of regional meltwater storage prior to east–west ORM flooding. The ORM channel and overlying esker‐fan sediment ridge represent two closely timed meltwater drainage events rather than formation by coalescing ice streams. The scale and timing of the ORM flood events are linked to rapid sea‐level rise, ~13.5 ka BP. This high‐resolution ORM sedimentological record may provide insights into depositional and glaciogenic ... Article in Journal/Newspaper Ice Sheet Wiley Online Library Canada West Ridge ENVELOPE(-137.021,-137.021,63.833,63.833) Boreas 52 3 341 380 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
High‐quality subsurface data provide new insights into the formation of Oak Ridges Moraine (ORM), an ~80 km 3 sequence of stratified meltwater deposits resting >200 m above adjacent Lake Ontario. The ORM sedimentary succession comprises a three‐part regional architecture: (i) ~north–south channel sand–gravel; (ii) channel‐capping rhythmites; and (iii) east–west ridge sediments. The ORM depositional sequence overlies a regional unconformity with a cross‐cutting channel network resulting from ~north–south meltwater floods that transitioned progressively (falling stage) from a ~NNE to ENE flow direction (parallels Lake Ontario depression). Seismic profiles delineate the channels and channel fill characteristics of bank‐to‐bank channel sedimentation of thick gradational gravel–sand–mud sequences. Channel‐capping mud (~100–236 rhythmites) within multiple channels beneath the ORM landform mark a widespread interval of low‐energy, seasonally controlled subglacial pond deposition. During this quiescent period ice‐sheet thickness adjusted to flood‐induced stretching/thinning and re‐profiled slopes. New ice gradients led to east–west flow and deposition of the overlying third element, a sequence of high‐energy confined esker–fan sediments along ORM ridge. Close, sequential timing (~329 varve years) of channel, basin and ridge‐forming architectural elements supports naming this assemblage the ORM formation. Proposed ORM floods are analogous to Icelandic jökulhlaups based on the size, geometry and sedimentology. The observed rhythmite interval between flood events represents a short period (~236 years) of regional meltwater storage prior to east–west ORM flooding. The ORM channel and overlying esker‐fan sediment ridge represent two closely timed meltwater drainage events rather than formation by coalescing ice streams. The scale and timing of the ORM flood events are linked to rapid sea‐level rise, ~13.5 ka BP. This high‐resolution ORM sedimentological record may provide insights into depositional and glaciogenic ... |
format |
Article in Journal/Newspaper |
author |
Sharpe, David R. Russell, Hazen A. J. |
spellingShingle |
Sharpe, David R. Russell, Hazen A. J. Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada |
author_facet |
Sharpe, David R. Russell, Hazen A. J. |
author_sort |
Sharpe, David R. |
title |
Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada |
title_short |
Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada |
title_full |
Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada |
title_fullStr |
Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada |
title_full_unstemmed |
Sedimentary architecture and glacial hydrodynamic significance of the stratified Oak Ridges Moraine, southern Ontario, Canada |
title_sort |
sedimentary architecture and glacial hydrodynamic significance of the stratified oak ridges moraine, southern ontario, canada |
publisher |
Wiley |
publishDate |
2023 |
url |
http://dx.doi.org/10.1111/bor.12612 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12612 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12612 |
long_lat |
ENVELOPE(-137.021,-137.021,63.833,63.833) |
geographic |
Canada West Ridge |
geographic_facet |
Canada West Ridge |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Boreas volume 52, issue 3, page 341-380 ISSN 0300-9483 1502-3885 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1111/bor.12612 |
container_title |
Boreas |
container_volume |
52 |
container_issue |
3 |
container_start_page |
341 |
op_container_end_page |
380 |
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1800753562767065088 |