TABLE 1.

Characteristics of McMurdo Ice Shelf sediments^a

Pond	Description	Density (g cm−3)	Dry weight (% of wet wt)	% Organic matter (dry wt)
Fresh	Gravel	1.99	77.6	1.2
Orange	Gravel, decaying mat	1.48	48.7	4.2
P-70	Gravel, decaying mat	1.40	44.7	7.7
Skua	Gravel, decaying mat	1.35	36.7	6.4
Brack	Medium sand	1.66	62.1	3.3
Salt	Medium sand	1.96	81.1	1.3

^aSediments were taken from a depth of 0 to 5 cm below the cyanobacterial mat at a water depth of 10 to 20 cm.