MAGNETIC PROPERTIES OF HOLOCENE EDAPHIZED SILTY EOLIAN SEDIMENTS FROM TIERRA DEL FUEGO (ARGENTINA)

MARÍA JULIA ORGEIRA; C.A. VÁSQUEZ; ANDREA CORONATO; JUAN FEDERICO PONCE; ALICIA MORETTO; MARGARITA OSTERRIETH; RAMON EGLI; MARÍA ROMINA ONORATO

Revista de la Sociedad Geológia de España

Facultad de Ciencias, Universidad de Salamanca

Año: 2012 vol. 25 p. 45 - 56

0214-2708

In this contribution we present preliminary environmental magnetism result from 80 samples collected along an eolian sedimentary sequence with 8 interbedded paleosols. 14C data indictes that the studied record represents the Holecene. The results principally include hysteresis data at room temperature, variation of magnetic susceptibility at two frequencies, and susceptibility at high and low temperatures in selected samples. The result discussed here suggest that the humidity during the formation of the studied paleosols was variable for each one. This means the alternating of wet and dry periods throughout the entire Holocene have been of different intensities. The magnetic results, together with some other properties of the geological record define a high climate variability occurring in the southern extremity of the Americas. A period of higher humidity than the present is suggested by the magnetic parameters during the period represented by the paleosols P7 (471 yrs BP), P5 (5552 yrs BP), P4 (6538 yrs BP) and P2 (age between 7163 and 11308 yrs BP).