Magnetization of Extraterrestrial Allende material may relate to terrestrial descend

0490441 - GLÚ 2019 RIV NL eng J - Článek v odborném periodiku
Kletetschka, Günther
Magnetization of Extraterrestrial Allende material may relate to terrestrial descend.
Earth and Planetary Science Letters. Roč. 487, 1 April 2018 (2018), s. 1-8. ISSN 0012-821X. E-ISSN 1385-013X
Institucionální podpora: RVO:67985831
Klíčová slova: Allende * magnetic dynamo * paleomagnetism * bolide * decelerating magnetization
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 4.637, rok: 2018

The origin of magnetization in Allende may have significant implications for our understanding of core formation/differentiation/dynamo processes in chondrite parent bodies. The magnetic Allende data may contain information that could constrain the magnetic history of Allende. The measurements on Allende chondrules reveal an existence of magnetization component that was likely acquired during the meteorite transit to terrestrial conditions. Both the pyrrhotite carrying magnetic remanence intensity and direction of the chondrules change erratically when subjecting the Allende meteorite's chondrules to temperatures near 77 K and back to room temperature. Chondrules with more intense original magnetization are denser and contain larger inverse thermoremanent magnetization (lTRM). Temperature dependent monitoring of lTRM revealed that magnetization was acquired at temperature near 270 K. Such temperature is consistent with the condition when, in addition to temperature increase, the atmospheric uniaxial pressure applied during the meteorite entry on the porous material was responsible for meteorite break up in the atmosphere. During this process, collapse of the pore space in the matrix and some chondrules would generate crystalline anisotropy energy accumulation within pyrrhotite grains in form of parasitic magnetic transition.
Trvalý link: http://hdl.handle.net/11104/0284662