Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada
The Liard Basin, in northwestern Canada, contains one of Canada’s largest natural gas reserves. There are concerns about degradation of Dunvegan Formation groundwater quality, which is the basin's main shallow freshwater aquifer, as a consequence of oil and gas development. Previous lithostrati...
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crcansciencepubl:10.1139/cjes-2022-0045 2023-12-17T10:47:42+01:00 Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada Glas, Nathan H. Bhattacharya, Janok P. Steelman, Colby M. Munn, Jonathan D. Pierce, Amanda A. Parker, Beth L. 2022 http://dx.doi.org/10.1139/cjes-2022-0045 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2022-0045 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2022-0045 en eng Canadian Science Publishing https://creativecommons.org/licenses/by/4.0/deed.en_GB Canadian Journal of Earth Sciences volume 59, issue 12, page 984-1005 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 2022 crcansciencepubl https://doi.org/10.1139/cjes-2022-0045 2023-11-19T13:38:54Z The Liard Basin, in northwestern Canada, contains one of Canada’s largest natural gas reserves. There are concerns about degradation of Dunvegan Formation groundwater quality, which is the basin's main shallow freshwater aquifer, as a consequence of oil and gas development. Previous lithostratigraphic studies interpreted the Dunvegan as conglomeratic alluvial fans. In this study, newly collected cores and surface resistivity surveys are integrated with legacy hydrocarbon well data and measured sections for improved sedimentary bedrock characterization. Rather than alluvial fans, we interpret the upper Dunvegan as a coarse-sand to gravel bed fluvial system that was likely tributive to incised valleys associated with linked Alberta Basin base-level falls. Correlation of well logs and measured sections suggest the lower Dunvegan comprises a prograding delta complex with off-lapping clinoforms fed by smaller sand-bed rivers that grade into the upper Dunvegan conglomeratic system, which built southeast towards the Cretaceous Western Interior Seaway. This sequence stratigraphic and facies architectural approach is employed to inform the aquifer–aquitard flow system and aid in understanding the 3D groundwater flow system, once hydrogeologic characterisation confirms position and thickness of important hydrogeologic units. Resistivity surveys suggest upper Dunvegan channel-belt facies may be well-connected and laterally extensive, potentially acting as interconnected aquifer units; whereas lower Dunvegan channel belts may be discontinuous, indicating smaller-scale flow units separated by floodplain and marine shale. This revised geologic understanding provides opportunities for determining impacts or resilience from shallow and deep sources of contamination associated with human activities, including oil and gas development, land-use, and (or) climate change. Article in Journal/Newspaper Northwest Territories Canadian Science Publishing (via Crossref) Northwest Territories Canada Liard ENVELOPE(-67.417,-67.417,-66.850,-66.850) Dunvegan ENVELOPE(-118.603,-118.603,55.917,55.917) Canadian Journal of Earth Sciences |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Glas, Nathan H. Bhattacharya, Janok P. Steelman, Colby M. Munn, Jonathan D. Pierce, Amanda A. Parker, Beth L. Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada |
topic_facet |
General Earth and Planetary Sciences |
description |
The Liard Basin, in northwestern Canada, contains one of Canada’s largest natural gas reserves. There are concerns about degradation of Dunvegan Formation groundwater quality, which is the basin's main shallow freshwater aquifer, as a consequence of oil and gas development. Previous lithostratigraphic studies interpreted the Dunvegan as conglomeratic alluvial fans. In this study, newly collected cores and surface resistivity surveys are integrated with legacy hydrocarbon well data and measured sections for improved sedimentary bedrock characterization. Rather than alluvial fans, we interpret the upper Dunvegan as a coarse-sand to gravel bed fluvial system that was likely tributive to incised valleys associated with linked Alberta Basin base-level falls. Correlation of well logs and measured sections suggest the lower Dunvegan comprises a prograding delta complex with off-lapping clinoforms fed by smaller sand-bed rivers that grade into the upper Dunvegan conglomeratic system, which built southeast towards the Cretaceous Western Interior Seaway. This sequence stratigraphic and facies architectural approach is employed to inform the aquifer–aquitard flow system and aid in understanding the 3D groundwater flow system, once hydrogeologic characterisation confirms position and thickness of important hydrogeologic units. Resistivity surveys suggest upper Dunvegan channel-belt facies may be well-connected and laterally extensive, potentially acting as interconnected aquifer units; whereas lower Dunvegan channel belts may be discontinuous, indicating smaller-scale flow units separated by floodplain and marine shale. This revised geologic understanding provides opportunities for determining impacts or resilience from shallow and deep sources of contamination associated with human activities, including oil and gas development, land-use, and (or) climate change. |
format |
Article in Journal/Newspaper |
author |
Glas, Nathan H. Bhattacharya, Janok P. Steelman, Colby M. Munn, Jonathan D. Pierce, Amanda A. Parker, Beth L. |
author_facet |
Glas, Nathan H. Bhattacharya, Janok P. Steelman, Colby M. Munn, Jonathan D. Pierce, Amanda A. Parker, Beth L. |
author_sort |
Glas, Nathan H. |
title |
Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada |
title_short |
Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada |
title_full |
Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada |
title_fullStr |
Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada |
title_full_unstemmed |
Evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the Upper Cretaceous Dunvegan Formation, Northwest Territories, Canada |
title_sort |
evolution of a stratigraphic model in a fluvial deltaic wedge: implications for groundwater resource protection in an oil and gas-bearing region in the upper cretaceous dunvegan formation, northwest territories, canada |
publisher |
Canadian Science Publishing |
publishDate |
2022 |
url |
http://dx.doi.org/10.1139/cjes-2022-0045 https://cdnsciencepub.com/doi/full-xml/10.1139/cjes-2022-0045 https://cdnsciencepub.com/doi/pdf/10.1139/cjes-2022-0045 |
long_lat |
ENVELOPE(-67.417,-67.417,-66.850,-66.850) ENVELOPE(-118.603,-118.603,55.917,55.917) |
geographic |
Northwest Territories Canada Liard Dunvegan |
geographic_facet |
Northwest Territories Canada Liard Dunvegan |
genre |
Northwest Territories |
genre_facet |
Northwest Territories |
op_source |
Canadian Journal of Earth Sciences volume 59, issue 12, page 984-1005 ISSN 0008-4077 1480-3313 |
op_rights |
https://creativecommons.org/licenses/by/4.0/deed.en_GB |
op_doi |
https://doi.org/10.1139/cjes-2022-0045 |
container_title |
Canadian Journal of Earth Sciences |
_version_ |
1785571644371107840 |