Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway.
Cave passages and karst features form negative density contrasts expressed in gravity field anomalies. We present an interpretation approach for microgravimetry, applicable for challenging geological settings with heterogeneous lithologies. The workflow covers not only detection of large cave rooms,...
Published in: | Norwegian Journal of Geology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Geological Society of Norway
2018
|
Subjects: | |
Online Access: | http://hdl.handle.net/11250/2592620 https://doi.org/10.17850/njg98-3-04 |
id |
ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2592620 |
---|---|
record_format |
openpolar |
spelling |
ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2592620 2023-05-15T17:24:40+02:00 Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. Solbakk, Terje Fichler, Christine Wheeler, Walter H Lauritzen, Stein-Erik Ringrose, Philip 2018 http://hdl.handle.net/11250/2592620 https://doi.org/10.17850/njg98-3-04 eng eng Geological Society of Norway https://njg.geologi.no/vol-91-100/details/1/2182-2182 Norsk Geologisk Tidsskrift. 2018, 98 (3), 359-378. urn:issn:0029-196X http://hdl.handle.net/11250/2592620 https://doi.org/10.17850/njg98-3-04 cristin:1641052 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no CC-BY 359-378 98 Norsk Geologisk Tidsskrift 3 Journal article Peer reviewed 2018 ftntnutrondheimi https://doi.org/10.17850/njg98-3-04 2019-09-17T06:54:51Z Cave passages and karst features form negative density contrasts expressed in gravity field anomalies. We present an interpretation approach for microgravimetry, applicable for challenging geological settings with heterogeneous lithologies. The workflow covers not only detection of large cave rooms, but also deals with minor karst features (epikarst) in carbonate rocks. Challenges due to heterogeneous infill of large cavities and variations in carbonate facies are addressed. We used 3D forward modelling of surface gravity measurements to investigate a large karst cave complex, known as the Svarthammarhola cave, in the Caledonian nappe setting of Nordland. The most important result relates to distinct gravity lows detected in the survey, which are interpreted as hitherto unknown and inaccessible cave rooms, some of them of a very large size. These correspond with known collapse and sediment infill features both at the surface and inside the Svarthammarhola cave system. This expands the known cave in an eastward and northward direction. Combining the cave’s position at the top of the hinge of a large antiform where we also modelled uncommonly high densities, together with the cave’s outstanding size, opens for new interpretations of the speleogenesis of the Svarthammarhola cave. The study also has wider implications on how gravity field data can be used for the understanding of complex subsurface karst features. publishedVersion © Copyright the authors. This work is licensed under a Creative Commons Attribution 4.0 International License. Article in Journal/Newspaper Nordland Nordland Nordland NTNU Open Archive (Norwegian University of Science and Technology) Mefjell ENVELOPE(22.129,22.129,69.985,69.985) Norway Norwegian Journal of Geology |
institution |
Open Polar |
collection |
NTNU Open Archive (Norwegian University of Science and Technology) |
op_collection_id |
ftntnutrondheimi |
language |
English |
description |
Cave passages and karst features form negative density contrasts expressed in gravity field anomalies. We present an interpretation approach for microgravimetry, applicable for challenging geological settings with heterogeneous lithologies. The workflow covers not only detection of large cave rooms, but also deals with minor karst features (epikarst) in carbonate rocks. Challenges due to heterogeneous infill of large cavities and variations in carbonate facies are addressed. We used 3D forward modelling of surface gravity measurements to investigate a large karst cave complex, known as the Svarthammarhola cave, in the Caledonian nappe setting of Nordland. The most important result relates to distinct gravity lows detected in the survey, which are interpreted as hitherto unknown and inaccessible cave rooms, some of them of a very large size. These correspond with known collapse and sediment infill features both at the surface and inside the Svarthammarhola cave system. This expands the known cave in an eastward and northward direction. Combining the cave’s position at the top of the hinge of a large antiform where we also modelled uncommonly high densities, together with the cave’s outstanding size, opens for new interpretations of the speleogenesis of the Svarthammarhola cave. The study also has wider implications on how gravity field data can be used for the understanding of complex subsurface karst features. publishedVersion © Copyright the authors. This work is licensed under a Creative Commons Attribution 4.0 International License. |
format |
Article in Journal/Newspaper |
author |
Solbakk, Terje Fichler, Christine Wheeler, Walter H Lauritzen, Stein-Erik Ringrose, Philip |
spellingShingle |
Solbakk, Terje Fichler, Christine Wheeler, Walter H Lauritzen, Stein-Erik Ringrose, Philip Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. |
author_facet |
Solbakk, Terje Fichler, Christine Wheeler, Walter H Lauritzen, Stein-Erik Ringrose, Philip |
author_sort |
Solbakk, Terje |
title |
Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. |
title_short |
Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. |
title_full |
Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. |
title_fullStr |
Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. |
title_full_unstemmed |
Detecting multiscale karst features including hidden caves using microgravimetry in a Caledonian nappe setting: Mefjell massif, Norway. |
title_sort |
detecting multiscale karst features including hidden caves using microgravimetry in a caledonian nappe setting: mefjell massif, norway. |
publisher |
Geological Society of Norway |
publishDate |
2018 |
url |
http://hdl.handle.net/11250/2592620 https://doi.org/10.17850/njg98-3-04 |
long_lat |
ENVELOPE(22.129,22.129,69.985,69.985) |
geographic |
Mefjell Norway |
geographic_facet |
Mefjell Norway |
genre |
Nordland Nordland Nordland |
genre_facet |
Nordland Nordland Nordland |
op_source |
359-378 98 Norsk Geologisk Tidsskrift 3 |
op_relation |
https://njg.geologi.no/vol-91-100/details/1/2182-2182 Norsk Geologisk Tidsskrift. 2018, 98 (3), 359-378. urn:issn:0029-196X http://hdl.handle.net/11250/2592620 https://doi.org/10.17850/njg98-3-04 cristin:1641052 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.17850/njg98-3-04 |
container_title |
Norwegian Journal of Geology |
_version_ |
1766115782723371008 |