English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/124586
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

A rock magnetic profile through the ejecta flap of the Lockne impact crater (central Sweden) and implications for the impact excavation process

AuthorsMelero-Asensio, Irene ; Martín Hernández, Fátima ; Ormö, Jens
KeywordsImpact crater
Rock magnetism
Marine target
Flap formation process
Lockne crater
Issue Date18-Nov-2014
PublisherElsevier
CitationJournal of Applied Geophysics, 112: 91–105 (2015)
AbstractThe well-documented, well-preserved, and well-exposed Lockne crater is a reference crater for marine-target impacts on Earth. The large amount of data allows detailed analysis of the cratering and modification processes. A unique feature of Lockne as compared with other similar craters is its pristine ejecta layer. Here, we provide the first complete lithological description coupled with an analysis of the rock magnetic properties of the Lockne-9 core drilled through the ejecta flap. Low-field bulk magnetic susceptibility, magnetic hysteresis, isothermal remanent magnetization curves (IRM), and the corresponding model of the coercivity spectra, backfield IRM, and thermomagnetic curves are used to fully characterize the magnetic mineralogy (i.e., pseudo-single domain (PSD) magnetite and pyrite). Variation of the magnetic properties with depth reveals a characteristic maximum in the magnetic susceptibility and magnetization within the crystalline ejecta. The magnetic properties of rocks affected by the impact show a slight weakening in the coercivity of magnetic minerals in comparison with rocks not affected by the impact. Altogether, this suggests to us that the high magnetization zone already existed before the impact event took place. Therefore, it can be inferred that during the cratering process, the Lockne ejecta was repositioned en masse from the central part of the crater in the form of an ejecta flap. This stands in contrast to the standard ballistic emplacement model wherein individual particles move in an ejecta curtain.
Publisher version (URL)http://dx.doi.org/10.1016/j.jappgeo.2014.11.009
URIhttp://hdl.handle.net/10261/124586
DOI10.1016/j.jappgeo.2014.11.009
ISSN0926-9851
E-ISSN1879-1859
Appears in Collections:(CAB) Artículos
(IGEO) Artículos
Files in This Item:
File Description SizeFormat 
JAP_2015_112_91.pdf2,11 MBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.