Table III.

Extractable arsenic content of sediments.

			Arsenic(nmol/g)
Core number	Altitude (m)a	Mineral fraction	Oxidativeb	Reductivec
< 2 mm size fraction
R23AWC02d	13.4 ± 0.2	whole	4.0 ± 0.2	1.08 ± 0.03
R23AWC02e	12.9 ± 0.2	whole	2.3 ± 0.7	1.11 ± 0.01
R23AWC03f	13.4 ± 0.2	whole	3.2 ± 1.1	0.98 ± 0.04
R23AWC03g	12.9 ± 0.2	whole	2.0 ± 0.6	0.97 ± 0.02
94UZComposite		wholeh	5.18 ± 0.02	0.91 ± 0.02
> 2 mm size fraction
R23AWC03	13.4 ± 0.2	whole except quartz	1.54	0.90
R23AWC03i	13.4 ± 0.2	quartz grains	nd	0.66
R23AWC02	13.4 ± 0.2	whole except quartz	0.33	1.49
R23AWC02j	13.4 ± 0.2	quartz grains	nd	1.77

nd=not determined.

^aAltitude (meters to sea level) of middle of 0.4-m-long cored interval.

^bHot, concentrated nitric acid and hydrogen peroxide.

^cHydroxylamine hydrochloride at 50°C for 96 h.

^d< 2 mm size fraction comprised 97% by weight of sample.

^e< 2 mm size fraction comprised 90% by weight of sample.

^f< 2 mm size fraction comprised 98% by weight of sample.

^g<2 mm size fraction comprised 91% by weight of sample.

^h< 1 mm size fraction.

ⁱQuartz grains comprised 36% by weight of >2 mm size fraction.

^JQuartz grains comprised 22% by weight of >2 mm size fraction.