Generation of Buried Transient Landscapes and Residual Depth Anomalies
During Cenozoic times, the Icelandic plume has played a dominant role in controlling periodic uplift of oceanographic gateways across the North Atlantic Ocean. Five exquisitely preserved Paleogene buried landscapes are mapped on three-dimensional seismic reflection surveys from the Faroe-Shetland ba...
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University of Cambridge
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ftunivcam:oai:www.repository.cam.ac.uk:1810/342315 2024-01-21T10:07:28+01:00 Generation of Buried Transient Landscapes and Residual Depth Anomalies Conway-Jones, Benedict 2022-10-21T09:05:50Z application/pdf https://www.repository.cam.ac.uk/handle/1810/342315 https://doi.org/10.17863/CAM.89737 eng eng University of Cambridge https://www.repository.cam.ac.uk/handle/1810/342315 doi:10.17863/CAM.89737 All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ Iceland Plume Dynamic Topography Paleoclimatology Faroe-Shetland Basin Thesis Doctoral Doctor of Philosophy (PhD) 2022 ftunivcam https://doi.org/10.17863/CAM.89737 2023-12-28T23:23:01Z During Cenozoic times, the Icelandic plume has played a dominant role in controlling periodic uplift of oceanographic gateways across the North Atlantic Ocean. Five exquisitely preserved Paleogene buried landscapes are mapped on three-dimensional seismic reflection surveys from the Faroe-Shetland basin. A regional biostratigraphic and lithostratigraphic framework shows that these transient landscapes recur at intervals of 2–4 million years. Dendritic drainage patterns recovered from these landscapes are disequilibrated and contain multiple knickzones and knickpoints that are systematically arranged within catchment areas. Applying the stream power law, longitudinal river profiles are inverted to calculate spatially and temporally varying uplift histories. These unique landscapes are attributed to laterally advecting pulses of hot material that travel away from the centre of the Icelandic plume. Kinematic modelling suggests that these pulses are 100±50 °C hotter than ambient plume material. There is a temporal relationship between timings of landscape exposure and transient volcanic activity. Globally, these landscapes are coeval with short-lived climatic hyperthermal events. A causal relationship is proposed, whereby pulses of basaltic volcanism serve as both sources of CO2 and triggers for methane release, thus generating hyperthermal aberrations. The present-day surface expression of the Icelandic plume is evaluated using a comprehensive database of residual depth measurements. This database suggests that the Icelandic plume head has a radius of ∼1500 km and a complex planform, consistent with free-air gravity and earthquake tomographic models. These observations cannot be reconciled with previous models of asthenospheric flow and lead to revised estimates of plume flux. An exhaustive database of residual depth measurements throughout the Atlantic Ocean is also presented. In particular, newly acquired seismic reflection surveys along the west coast of Africa reveal that dynamic topography varies spatially on ... Doctoral or Postdoctoral Thesis Iceland North Atlantic Apollo - University of Cambridge Repository |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Iceland Plume Dynamic Topography Paleoclimatology Faroe-Shetland Basin |
spellingShingle |
Iceland Plume Dynamic Topography Paleoclimatology Faroe-Shetland Basin Conway-Jones, Benedict Generation of Buried Transient Landscapes and Residual Depth Anomalies |
topic_facet |
Iceland Plume Dynamic Topography Paleoclimatology Faroe-Shetland Basin |
description |
During Cenozoic times, the Icelandic plume has played a dominant role in controlling periodic uplift of oceanographic gateways across the North Atlantic Ocean. Five exquisitely preserved Paleogene buried landscapes are mapped on three-dimensional seismic reflection surveys from the Faroe-Shetland basin. A regional biostratigraphic and lithostratigraphic framework shows that these transient landscapes recur at intervals of 2–4 million years. Dendritic drainage patterns recovered from these landscapes are disequilibrated and contain multiple knickzones and knickpoints that are systematically arranged within catchment areas. Applying the stream power law, longitudinal river profiles are inverted to calculate spatially and temporally varying uplift histories. These unique landscapes are attributed to laterally advecting pulses of hot material that travel away from the centre of the Icelandic plume. Kinematic modelling suggests that these pulses are 100±50 °C hotter than ambient plume material. There is a temporal relationship between timings of landscape exposure and transient volcanic activity. Globally, these landscapes are coeval with short-lived climatic hyperthermal events. A causal relationship is proposed, whereby pulses of basaltic volcanism serve as both sources of CO2 and triggers for methane release, thus generating hyperthermal aberrations. The present-day surface expression of the Icelandic plume is evaluated using a comprehensive database of residual depth measurements. This database suggests that the Icelandic plume head has a radius of ∼1500 km and a complex planform, consistent with free-air gravity and earthquake tomographic models. These observations cannot be reconciled with previous models of asthenospheric flow and lead to revised estimates of plume flux. An exhaustive database of residual depth measurements throughout the Atlantic Ocean is also presented. In particular, newly acquired seismic reflection surveys along the west coast of Africa reveal that dynamic topography varies spatially on ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Conway-Jones, Benedict |
author_facet |
Conway-Jones, Benedict |
author_sort |
Conway-Jones, Benedict |
title |
Generation of Buried Transient Landscapes and Residual Depth Anomalies |
title_short |
Generation of Buried Transient Landscapes and Residual Depth Anomalies |
title_full |
Generation of Buried Transient Landscapes and Residual Depth Anomalies |
title_fullStr |
Generation of Buried Transient Landscapes and Residual Depth Anomalies |
title_full_unstemmed |
Generation of Buried Transient Landscapes and Residual Depth Anomalies |
title_sort |
generation of buried transient landscapes and residual depth anomalies |
publisher |
University of Cambridge |
publishDate |
2022 |
url |
https://www.repository.cam.ac.uk/handle/1810/342315 https://doi.org/10.17863/CAM.89737 |
genre |
Iceland North Atlantic |
genre_facet |
Iceland North Atlantic |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/342315 doi:10.17863/CAM.89737 |
op_rights |
All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ |
op_doi |
https://doi.org/10.17863/CAM.89737 |
_version_ |
1788698067079266304 |