3_t01.htm

Table T1. XRF analytical conditions for Leg 179.

Oxide or element	Line	Crystal	Detector	Collimator	Peak angle (°2)	Background offset (°2)	Count time on peak (s)	Count time on background (s)	Analytical error (rel %)	Detection limit
SiO₂	K	PET	FPC	Medium	109.21		40		0.30	0.03
TiO₂	K	LIF200	FPC	Fine	86.14		40		0.37	0.01
Al₂O₃	K	PET	FPC	Medium	145.12		100		0.40	0.01
Fe₂O₃	K	LIF200	FPC	Fine	57.52		40		0.20	0.01
MnO	K	LIF200	FPC	Fine	62.97		100		0.10	0.005
MgO	K	TLAP	FPC	Medium	45.17	±0.80	150	150	0.60	0.01
CaO	K	LIF200	FPC	Medium	113.09		40		0.30	0.005
Na₂O	K	TLAP	FPC	Medium	54.10	-1.20	150	150	3.8	0.03
K₂O	K	LIF200	FPC	Medium	136.69		100		0.40	0.01
P₂O₅	K	GE111	FPC	Medium	141.04		100		0.40	0.01
Rh	K Compton	LIF200	Scint	Fine	18.58		60
Nb	K	LIF200	Scint	Fine	21.40	+0.35	200	100	0.2	0.5
Zr	K	LIF200	Scint	Fine	22.55	-0.35	100	50	0.5	0.6
Y	K	LIF200	Scint	Fine	23.80	-0.40	100	50	1.0	0.6
Sr	K	LIF200	Scint	Fine	25.15	-0.40	100	50	0.3	0.6
Rb	K	LIF200	Scint	Fine	26.62	-0.60	100	50	3.6	0.6
Zn	K	LIF200	Scint	Medium	41.81	-0.55	100	50	1.0	1.0
Cu	K	LIF200	Scint	Fine	45.03	-0.55	100	50	1.5	1.2
Ni	K	LIF200	Scint	Medium	48.67	-0.60	100	50	0.6	1.2
Cr	K	LIF200	FPC	Fine	69.35	-0.50	100	50	1.3	2.0
V	K	LIF220	FPC	Fine	123.06	-0.50	100	50	2.0	3.0
Ti	K	LIF200	FPC	Fine	86.14	+0.50	40	20
Ce	L	LIF220	FPC	Medium	128.13	-1.50	100	50
Ba	Lß	LIF220	FPC	Medium	128.78	-1.50	100	50

Notes: All major elements measured using a Rhodium X-ray tube operated at 30 kV and 80 mA. Trace elements are measured using a Rhodium X-ray tube operated at 60 kV and 50 mA. Detector: FPC = flow proportional counter (P10 gas); Scint = NaI Scintillation counter. Detection limit units = weight percent for major elements, parts per million for trace elements.