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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-24 23:06 |
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Conference: Bucharest University Faculty of Physics 2003 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Rock Magnetic Properties of the Tuzla Loess Section
Authors:
Cristian Necula, Cristina Panaiotu, Cristian Panaiotu
Affiliation:
University of Bucharest,Faculty of Physics, Paleomagnetism Laboratory
P.O.Box MG-11, Bucharest
E-mail
Keywords:
Abstract:
The studied loess-paleosol sequence is located on the Black sea shore near the locality Tuzla. The length of the section is 8 m and it consists of two paleosols and two loess layers. Several rock magnetic parameters were measured on all 80 samples: frequency dependent susceptibility, isothermal remanent magnetization (IRM), anhisteretic remanent magnetisation, coercive force. The results show a strong magnetic contrast between paleosols and loess. This behavior is typical for mid-latitude loess, Chinese type, and it was recorded in others sequences studied in Romania. Both stepwise acquisitions of IRM and coercitive forces show that the main magnetic mineral is magnetite. Back field demagnetization curves of IRM at 300 mT and 2000 mT show that minor quantities of a high coercivity mineral (hematite ?) are present mainly in loess samples. Frequency dependent susceptibility reaches values between 8 – 12 % in paleosols illustrating the dominance of superparamagnetic magnetite in paleosols as a consequence of pedogenetic processes. The new results show that coercitive force is also strongly influenced by these processes (25-35 mT in paleosols, 35-50 mT in loess).
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