Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland
We investigated the natural remanent magnetization (Jr) of hydrothermally altered basalts from two drill cores KH1 (200 m) and KH3 (400 m) situated at the rim of the Krafla caldera in NE Iceland, where a geothermal field (>150°C) is still active. Low temperature oxidation along with mineral react...
Published in: | Studia Geophysica et Geodaetica |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Subjects: | |
Online Access: | https://kramerius.lib.cas.cz/view/uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 https://doi.org/10.1007/s11200-011-9013-9 |
id |
ftczechacademysc:oai:kramerius.lib.cas.cz:uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 |
---|---|
record_format |
openpolar |
spelling |
ftczechacademysc:oai:kramerius.lib.cas.cz:uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 2024-03-17T08:58:32+00:00 Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland Oliva-Urcia, Belén Kontny, Agnes print https://kramerius.lib.cas.cz/view/uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 https://doi.org/10.1007/s11200-011-9013-9 unknown https://kramerius.lib.cas.cz/view/uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 doi:https://doi.org/10.1007/s11200-011-9013-9 policy:private geofyzika geophysics low temperature oxidation paleomagnetism NRM Krafla 7 550 model:article ftczechacademysc https://doi.org/10.1007/s11200-011-9013-9 2024-02-19T22:57:32Z We investigated the natural remanent magnetization (Jr) of hydrothermally altered basalts from two drill cores KH1 (200 m) and KH3 (400 m) situated at the rim of the Krafla caldera in NE Iceland, where a geothermal field (>150°C) is still active. Low temperature oxidation along with mineral reactions in the chlorite zone (<350°C) is the prevailing cause for the maghemitization and a strong decrease of Jr to occur in our study. Despite a significant decrease of Jr with respect to fresh basalts in surface outcrops of the same area, the stepwise demagnetization analyses of Jr show the presence of a stable magnetic component with the expected inclination of 77° in Iceland. Because the alteration temperature (<350°C) is above the Curie temperatures of most of the original titanomagnetite (40°–350°C), we suggest that a normal direction of remanence is chemically acquired during the low temperature alteration. We observed only one reliable negative inclination at 293.2 m in the KH3 core, which we rather interpret to be acquired during a geomagnetic excursion with reverse polarity than caused by a self-reversal mechanism. Belén Oliva-Urcia, Agnes Kontny. Obsahuje seznam literatury Article in Journal/Newspaper Iceland Czech Academy of Sciences: dKNAV Krafla ENVELOPE(-16.747,-16.747,65.713,65.713) Oliva ENVELOPE(-60.783,-60.783,-62.450,-62.450) Studia Geophysica et Geodaetica 56 3 641 657 |
institution |
Open Polar |
collection |
Czech Academy of Sciences: dKNAV |
op_collection_id |
ftczechacademysc |
language |
unknown |
topic |
geofyzika geophysics low temperature oxidation paleomagnetism NRM Krafla 7 550 |
spellingShingle |
geofyzika geophysics low temperature oxidation paleomagnetism NRM Krafla 7 550 Oliva-Urcia, Belén Kontny, Agnes Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland |
topic_facet |
geofyzika geophysics low temperature oxidation paleomagnetism NRM Krafla 7 550 |
description |
We investigated the natural remanent magnetization (Jr) of hydrothermally altered basalts from two drill cores KH1 (200 m) and KH3 (400 m) situated at the rim of the Krafla caldera in NE Iceland, where a geothermal field (>150°C) is still active. Low temperature oxidation along with mineral reactions in the chlorite zone (<350°C) is the prevailing cause for the maghemitization and a strong decrease of Jr to occur in our study. Despite a significant decrease of Jr with respect to fresh basalts in surface outcrops of the same area, the stepwise demagnetization analyses of Jr show the presence of a stable magnetic component with the expected inclination of 77° in Iceland. Because the alteration temperature (<350°C) is above the Curie temperatures of most of the original titanomagnetite (40°–350°C), we suggest that a normal direction of remanence is chemically acquired during the low temperature alteration. We observed only one reliable negative inclination at 293.2 m in the KH3 core, which we rather interpret to be acquired during a geomagnetic excursion with reverse polarity than caused by a self-reversal mechanism. Belén Oliva-Urcia, Agnes Kontny. Obsahuje seznam literatury |
format |
Article in Journal/Newspaper |
author |
Oliva-Urcia, Belén Kontny, Agnes |
author_facet |
Oliva-Urcia, Belén Kontny, Agnes |
author_sort |
Oliva-Urcia, Belén |
title |
Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland |
title_short |
Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland |
title_full |
Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland |
title_fullStr |
Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland |
title_full_unstemmed |
Remanent magnetization of maghemitized basalts from Krafla drill cores, NE-Iceland |
title_sort |
remanent magnetization of maghemitized basalts from krafla drill cores, ne-iceland |
url |
https://kramerius.lib.cas.cz/view/uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 https://doi.org/10.1007/s11200-011-9013-9 |
long_lat |
ENVELOPE(-16.747,-16.747,65.713,65.713) ENVELOPE(-60.783,-60.783,-62.450,-62.450) |
geographic |
Krafla Oliva |
geographic_facet |
Krafla Oliva |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
https://kramerius.lib.cas.cz/view/uuid:d4beb07c-e043-4574-9f95-abf3d5b59931 doi:https://doi.org/10.1007/s11200-011-9013-9 |
op_rights |
policy:private |
op_doi |
https://doi.org/10.1007/s11200-011-9013-9 |
container_title |
Studia Geophysica et Geodaetica |
container_volume |
56 |
container_issue |
3 |
container_start_page |
641 |
op_container_end_page |
657 |
_version_ |
1793768201035710464 |