| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:46 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2013 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Unmixing of Isothermal Remanent Magnetization curves measured in a Romanian loess deposit
Authors:
Cristian Necula(1), Cristian Panaiotu(1), Daniela Dimofte(2)
Affiliation:
(1)University of Bucharest,Faculty of Physics, Paleomagnetic Laboratory, P.O.BOX MG-11, Magurele, Romania
(2)faculty of Geology and Geophysics, University of Bucharest
E-mail
c3necula@yahoo.com
Keywords:
loess, IRM unmixing, paleoclimate
Abstract:
An unmixing model for isothermal remanent magnetization curves is used for analysis of the climatic control on magnetic granulometry in Mircea Voda loess deposit (Dobrogea Plateau, Romania). Rock-magnetic investigation showed that the paleosol layers in the Mircea Voda sequence experienced significant pedogenic alteration, resulting in high amounts of ultrafine grained SP, grains at SP/SD threshold, stable SD grains and PSD magnetite/maghemite grains. The loess layers in the Mircea Voda sequence are dominated by MD and/or PSD oxidized magnetite probably of aeolian origin. The unmixing model for IRM curves shows the presence of three components with different coercivities. The soft (~21 mT) and medium (~42 mT) coercivity components are produced by pedogenesis during interglacial and interstadial periods representing probably the contribution of the SP and SD particles respectively. The hard coercivity component (~60 mT) of aeolian origin corresponds to MD and/or PSD oxidized magnetite, being dominant in loess layers.
|
|
|
|