Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland).
18 pages International audience Soft-sediment deformation structures are being increasingly used as a tool for reconstructing palaeoenvironments and porewater pressure conditions in glacial settings. However, the potential of hydrofractures and clastic injections in the reconstruction of ice dynamic...
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Online Access: | https://hal.science/hal-01152529 https://doi.org/10.1016/j.sedgeo.2015.04.013 |
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ftunivbourgogne:oai:HAL:hal-01152529v1 2024-05-19T07:42:38+00:00 Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). Ravier, Edouard Buoncristiani, Jean-François Menzies, John Guiraud, Michel Portier, Eric Biogéosciences UMR 6282 (BGS) Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS) Department of Earth Sciences St. Catharines Brock University Canada Exploration Production International Gaz de France Suez (GDF Suez) Funding from GDF Suez. 2015-06-15 https://hal.science/hal-01152529 https://doi.org/10.1016/j.sedgeo.2015.04.013 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.sedgeo.2015.04.013 hal-01152529 https://hal.science/hal-01152529 doi:10.1016/j.sedgeo.2015.04.013 ISSN: 0037-0738 Sedimentary Geology https://hal.science/hal-01152529 Sedimentary Geology, 2015, 323, pp.92-109. ⟨10.1016/j.sedgeo.2015.04.013⟩ http://www.sciencedirect.com/science/article/pii/S0037073815001104 Clastic injections Hydrofracture Glacial sedimentology Micromorphology Palaeo-ice dynamics Iceland [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology info:eu-repo/semantics/article Journal articles 2015 ftunivbourgogne https://doi.org/10.1016/j.sedgeo.2015.04.013 2024-04-25T00:08:26Z 18 pages International audience Soft-sediment deformation structures are being increasingly used as a tool for reconstructing palaeoenvironments and porewater pressure conditions in glacial settings. However, the potential of hydrofractures and clastic injections in the reconstruction of ice dynamics remains poorly constrained. This paper presents the results of a detailed study of a clastic injection network outcropping in the Sólheimajökull forefield (South Iceland). Sedimentological descriptions are combined with microscopic to macroscopic analyses of clastic injection geometries, sediment-fills, and cross-cutting relationships. The 250 m long and 20 m high exposure observed along the east flank of the proglacial braid plain displays alternating glaciofluvial sediments and subglacial tills, illustrating oscillations of the ice margins. These sediments are cross-cut by a dense network of injection composed of dykes propagating upward or downward, sills, and stepped sills. These clastic injections result from processes of hydrofracturing and the sediment-fills in these hydrofractures are generally laminated with an increase of grain-size towards the centre of the injections. These fracture-fill characteristics suggest multiple injection phases within the hydrofractures and an increase of porewater pressure over time. Five main generations of clastic injections showing different senses of propagation and dip directions are determined and are interpreted as forming in different environments. Per descensum clastic dykes dipping down ice demonstrate subglacial hydrofracturing underneath flowing-ice, while sills and per ascensum clastic dykes form in submarginal to marginal environments due to the decrease of ice overburden pressure. The integration of these results with the sedimentological characteristics allows the Holocene ice front oscillations of the Sólheimajökull to be reconstructed. This study demonstrates the importance of hydrofracture systems and their sediment-fills in the reconstruction of ... Article in Journal/Newspaper Iceland Université de Bourgogne (UB): HAL Sedimentary Geology 323 92 109 |
institution |
Open Polar |
collection |
Université de Bourgogne (UB): HAL |
op_collection_id |
ftunivbourgogne |
language |
English |
topic |
Clastic injections Hydrofracture Glacial sedimentology Micromorphology Palaeo-ice dynamics Iceland [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
spellingShingle |
Clastic injections Hydrofracture Glacial sedimentology Micromorphology Palaeo-ice dynamics Iceland [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology Ravier, Edouard Buoncristiani, Jean-François Menzies, John Guiraud, Michel Portier, Eric Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). |
topic_facet |
Clastic injections Hydrofracture Glacial sedimentology Micromorphology Palaeo-ice dynamics Iceland [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
description |
18 pages International audience Soft-sediment deformation structures are being increasingly used as a tool for reconstructing palaeoenvironments and porewater pressure conditions in glacial settings. However, the potential of hydrofractures and clastic injections in the reconstruction of ice dynamics remains poorly constrained. This paper presents the results of a detailed study of a clastic injection network outcropping in the Sólheimajökull forefield (South Iceland). Sedimentological descriptions are combined with microscopic to macroscopic analyses of clastic injection geometries, sediment-fills, and cross-cutting relationships. The 250 m long and 20 m high exposure observed along the east flank of the proglacial braid plain displays alternating glaciofluvial sediments and subglacial tills, illustrating oscillations of the ice margins. These sediments are cross-cut by a dense network of injection composed of dykes propagating upward or downward, sills, and stepped sills. These clastic injections result from processes of hydrofracturing and the sediment-fills in these hydrofractures are generally laminated with an increase of grain-size towards the centre of the injections. These fracture-fill characteristics suggest multiple injection phases within the hydrofractures and an increase of porewater pressure over time. Five main generations of clastic injections showing different senses of propagation and dip directions are determined and are interpreted as forming in different environments. Per descensum clastic dykes dipping down ice demonstrate subglacial hydrofracturing underneath flowing-ice, while sills and per ascensum clastic dykes form in submarginal to marginal environments due to the decrease of ice overburden pressure. The integration of these results with the sedimentological characteristics allows the Holocene ice front oscillations of the Sólheimajökull to be reconstructed. This study demonstrates the importance of hydrofracture systems and their sediment-fills in the reconstruction of ... |
author2 |
Biogéosciences UMR 6282 (BGS) Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS) Department of Earth Sciences St. Catharines Brock University Canada Exploration Production International Gaz de France Suez (GDF Suez) Funding from GDF Suez. |
format |
Article in Journal/Newspaper |
author |
Ravier, Edouard Buoncristiani, Jean-François Menzies, John Guiraud, Michel Portier, Eric |
author_facet |
Ravier, Edouard Buoncristiani, Jean-François Menzies, John Guiraud, Michel Portier, Eric |
author_sort |
Ravier, Edouard |
title |
Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). |
title_short |
Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). |
title_full |
Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). |
title_fullStr |
Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). |
title_full_unstemmed |
Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland). |
title_sort |
clastic injection dynamics during ice front oscillations: a case example from sólheimajökull (iceland). |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-01152529 https://doi.org/10.1016/j.sedgeo.2015.04.013 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
ISSN: 0037-0738 Sedimentary Geology https://hal.science/hal-01152529 Sedimentary Geology, 2015, 323, pp.92-109. ⟨10.1016/j.sedgeo.2015.04.013⟩ http://www.sciencedirect.com/science/article/pii/S0037073815001104 |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.sedgeo.2015.04.013 hal-01152529 https://hal.science/hal-01152529 doi:10.1016/j.sedgeo.2015.04.013 |
op_doi |
https://doi.org/10.1016/j.sedgeo.2015.04.013 |
container_title |
Sedimentary Geology |
container_volume |
323 |
container_start_page |
92 |
op_container_end_page |
109 |
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1799482332598501376 |