A Deep Alteration and Oxidation Profile in a Shallow Clay Aquitard: Example of the Tégulines Clay, East Paris Basin, France

Table 2

Main results of magnetic remanence measurements: major magnetic Fe-bearing minerals, values of magnetic remanence measured at 300 K during the three successive cycles, loss of remanence between cycles 2 and 3, and estimation of goethite in samples.

	AUB131-5.41 m	AUB131-21.75 m	AUB1010-6.42 m	AUB1010-20.1 m	AUB1010-30.9 m
Magnetic minerals	Goethite	Goethite	Goethite, hematite	Goethite, magnetite, siderite?	Goethite, magnetite?, siderite?
M1 cycle 1 (300 K) Am^2/kg			n.d.
M2 cycle 2 (300 K) Am^2/kg
M3 cycle 3 (300 K) Am^2/kg
Remanence lost between cycles 2 and 3 (300 K)	46%	52%	29%	14%	52%
Goethite concentration	~1.95%	~1.8%	~2%	~1.24%	~0.8%