TABLE 1.

Locations and geochemical properties of lake sediments on the Qinghai-Tibetan Plateau

Location or geochemical property	Data for:
	EHL	QHL	GHL	XCDL	CKL
Geographic Position (N/E)	36.33/100.43	36.64/100.37	37.00/100.32	37.27/95.30	36.45/99.04
pHa	9.14	9.11	9.12	8.58	6.98
Salinitya (g/L)	0.67	13	33	40	346
Lake type	Freshwater	Polysaline	Polysaline	Polysaline	Hypersaline
Water content of sediment column (%)	53.78	35.78	27.61	16.54	62.11
Total phosphorusa (mg/L)	0.034	0.028	0.034	0.025	0.579
Total nitrogena (mg/L)	3.18	1.36	4.60	4.23	8.81
NO3−-Na (mg/L)	1.62	0.45	1.49	0.11	1.69
NH4+-Na (mg/L)	0.51	0.08	2.11	2.05	0.16
NOO3−-Nb (mg/kg)	2.54	8.27	2.49	2.59	NA
NH4+-Nb (mg/kg)	9.48	2.30	2.32	2.22	NA
Bioavailable Fe (wt % dry sediment)	0.11	0.10	0.08	0.01	0.18
Crystalline Fe (wt % dry sediment)	0.69	1.04	0.94	1.02	2.29

^aDetermined from water column.

^bDetermined from sediment column. Bioavailable Fe, 0.5 M HCl-extractable iron; Crystalline Fe, 6 M HCl-extractable iron. The concentrations of different iron fractions were reported as an average. EHL, Erhai Lake; QHL, Qinghai Lake; GHL, Gahai Lake; XCDL, Xiaochaidan Lake; CKL, Chaka Lake; NA, not available.