Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia
The aim of this study was to investigate the effect of meteorite impacts on magnetic properties including magnetic susceptibility and the Verwey transition of Ti-poor titanomagnetite of volcanic rocks from the 3.6 Ma old El’gygytgyn impact structure located in the Okhotsk-Chukotka volcanic belt in n...
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Springer Verlag
2016
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ftubkarlsruhe:oai:EVASTAR-Karlsruhe.de:1000062831 2023-05-15T15:54:53+02:00 Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia Kontny, Agnes Grothaus, Lea 2016-12-06 https://publikationen.bibliothek.kit.edu/1000062831 eng eng Springer Verlag info:eu-repo/semantics/altIdentifier/wos/000394273200009 info:eu-repo/semantics/altIdentifier/doi/10.1007/s11200-016-0819-3 info:eu-repo/semantics/altIdentifier/issn/0039-3169 info:eu-repo/semantics/altIdentifier/issn/1573-1626 https://publikationen.bibliothek.kit.edu/1000062831 info:eu-repo/semantics/closedAccess Studia geophysica et geodaetica ISSN: 0039-3169, 1573-1626 ddc:910 Geography & travel info:eu-repo/classification/ddc/910 doc-type:article Text info:eu-repo/semantics/article article 2016 ftubkarlsruhe https://doi.org/10.1007/s11200-016-0819-3 2022-03-23T18:24:49Z The aim of this study was to investigate the effect of meteorite impacts on magnetic properties including magnetic susceptibility and the Verwey transition of Ti-poor titanomagnetite of volcanic rocks from the 3.6 Ma old El’gygytgyn impact structure located in the Okhotsk-Chukotka volcanic belt in north-eastern Russia. The target rocks consist mainly of rhyolite with some andesites, and is a rare example of impact structures within volcanic target rocks on Earth. 27 samples from outside the crater, the crater rim and from the depth interval 316 to 517 m below lake bottom (mblb) of the El’gygytgyn ICDP drilling were studied. A significant decrease of the average specific magnetic susceptibility by around 90% was observed between felsic volcanic rocks from the surface (18.1 × 10-6 m3/kg) and the drill cores from near the crater central uplift (1.9 × 10-6 m3/kg). Ferrimagnetic Fe-Ti oxide assemblages (Verwey transition temperature, TV: -161 to -150°C, Curie temperature, TC: 451 to 581°C), occurring in all studied samples, differ significantly. At the surface titanomaghemite is ubiquitously associated with titanomagnetite. The drill cores lack titanomaghemite, but either show a transformation into titanomagnetite and ilmenite or a strong fragmentation associated with a second TV between -172 and -188°C. Reversible curves of temperature dependence of magnetic susceptibility in the suevite indicate high depositional temperatures of at least 500°C. In the polymict and monomict impact breccia mechanical deformation of titanomagnetite and temperatures of at least 200-350°C related to the shock are suggested from temperature dependent magnetic susceptibility cycling. Lowtemperature oxidation along strongly brecciated grain surfaces in titanomagnetite is suggested to cause the lower TV and we suggest that this phenomenon is related to postimpact hydrothermal activity. The strong magnetic susceptibility decrease at El’gygytgyn is mainly influenced by shock, and post-impact hydrothermalism causes a significant additional ... Article in Journal/Newspaper Chukotka KITopen (Karlsruhe Institute of Technologie) Okhotsk Studia Geophysica et Geodaetica 61 1 162 183 |
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Open Polar |
collection |
KITopen (Karlsruhe Institute of Technologie) |
op_collection_id |
ftubkarlsruhe |
language |
English |
topic |
ddc:910 Geography & travel info:eu-repo/classification/ddc/910 |
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ddc:910 Geography & travel info:eu-repo/classification/ddc/910 Kontny, Agnes Grothaus, Lea Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia |
topic_facet |
ddc:910 Geography & travel info:eu-repo/classification/ddc/910 |
description |
The aim of this study was to investigate the effect of meteorite impacts on magnetic properties including magnetic susceptibility and the Verwey transition of Ti-poor titanomagnetite of volcanic rocks from the 3.6 Ma old El’gygytgyn impact structure located in the Okhotsk-Chukotka volcanic belt in north-eastern Russia. The target rocks consist mainly of rhyolite with some andesites, and is a rare example of impact structures within volcanic target rocks on Earth. 27 samples from outside the crater, the crater rim and from the depth interval 316 to 517 m below lake bottom (mblb) of the El’gygytgyn ICDP drilling were studied. A significant decrease of the average specific magnetic susceptibility by around 90% was observed between felsic volcanic rocks from the surface (18.1 × 10-6 m3/kg) and the drill cores from near the crater central uplift (1.9 × 10-6 m3/kg). Ferrimagnetic Fe-Ti oxide assemblages (Verwey transition temperature, TV: -161 to -150°C, Curie temperature, TC: 451 to 581°C), occurring in all studied samples, differ significantly. At the surface titanomaghemite is ubiquitously associated with titanomagnetite. The drill cores lack titanomaghemite, but either show a transformation into titanomagnetite and ilmenite or a strong fragmentation associated with a second TV between -172 and -188°C. Reversible curves of temperature dependence of magnetic susceptibility in the suevite indicate high depositional temperatures of at least 500°C. In the polymict and monomict impact breccia mechanical deformation of titanomagnetite and temperatures of at least 200-350°C related to the shock are suggested from temperature dependent magnetic susceptibility cycling. Lowtemperature oxidation along strongly brecciated grain surfaces in titanomagnetite is suggested to cause the lower TV and we suggest that this phenomenon is related to postimpact hydrothermal activity. The strong magnetic susceptibility decrease at El’gygytgyn is mainly influenced by shock, and post-impact hydrothermalism causes a significant additional ... |
format |
Article in Journal/Newspaper |
author |
Kontny, Agnes Grothaus, Lea |
author_facet |
Kontny, Agnes Grothaus, Lea |
author_sort |
Kontny, Agnes |
title |
Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia |
title_short |
Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia |
title_full |
Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia |
title_fullStr |
Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia |
title_full_unstemmed |
Effects of shock pressure and temperature on titanomagnetite from ICDP cores and target rocks of the El’gygytgyn impact structure, Russia |
title_sort |
effects of shock pressure and temperature on titanomagnetite from icdp cores and target rocks of the el’gygytgyn impact structure, russia |
publisher |
Springer Verlag |
publishDate |
2016 |
url |
https://publikationen.bibliothek.kit.edu/1000062831 |
geographic |
Okhotsk |
geographic_facet |
Okhotsk |
genre |
Chukotka |
genre_facet |
Chukotka |
op_source |
Studia geophysica et geodaetica ISSN: 0039-3169, 1573-1626 |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/000394273200009 info:eu-repo/semantics/altIdentifier/doi/10.1007/s11200-016-0819-3 info:eu-repo/semantics/altIdentifier/issn/0039-3169 info:eu-repo/semantics/altIdentifier/issn/1573-1626 https://publikationen.bibliothek.kit.edu/1000062831 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1007/s11200-016-0819-3 |
container_title |
Studia Geophysica et Geodaetica |
container_volume |
61 |
container_issue |
1 |
container_start_page |
162 |
op_container_end_page |
183 |
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1766390130051907584 |