Chemistry 85 



TABLE 4-4 Chemistry of Pond J Water and of Interstitial Water of Ponds E 

 and J and Ikroavik Lake* 



Ca 



Na 



K Mg Fe 



Pond J, (water column), 

 7 July 1971 



Pond J, Central Basin, 

 11 July 1971.4-12cm 



Pond E, terrestrial Carex 

 stand, 20 July 1970, 7cm 

 Bore hole 1 

 Bore hole 2 



4.2 15.8 0.45 4.9 1.5 



14.5 24.0 0.70 11.0 17.1 



7.8 11.8 0.75 5.72 



6.6 14.0 0.24 4.22 



Ikroavik Lake, interstitial 

 water, 31 May 1971 



53.4 161 



3.96 19.8 13. 



*Data are expressed as mg liter- . 



The Pond J interstitial water is enriched relative to either the water 

 column above or the nearby terrestrial pore waters in all cations but 

 potassium (Table 4-4). The high concentrations of ions in the interstitial 

 waters from Ikroavik Lake are due to ion exclusion from the 2 m of ice 

 formed in winter. The smaller enrichment in cations in Pond J relative to 

 the pondwater above may also be due to cation exclusion from ice during 

 fall freeze-up, but the values for all ions fall within the range of pore water 

 for terrestrial Barrow area cores in general (Gersper et al. in press). The 

 difference in cation concentration between the water column and the 

 interstitial water is much greater than that found in lakes such as Lake 

 Ontario (Weiler 1973) which have no mechanism for forcing ions into 

 sediment. 



The Barrow pond sediments are best described as iron-rich peats. 

 Iron concentrations for two cores taken from Ponds B, C, and D in 1970 

 (Table 4-3) are 20% to 40% higher than those found in interior Alaska 

 subarctic lakes such as Smith (Alexander and Barsdate 1971), Birch, and 

 Harding Lakes (Barsdate and Matson 1966); but they still fall within the 

 range reported both for Linsley Pond (Hutchinson and Wollack 1940) and 

 for 14 soft water Wisconsin lakes (Williams et al. 1971a). Additional iron 

 determinations discussed later indicate that surficial sediments of some 

 ponds can contain much higher quantities, at least up to 133,000 ppm 

 total, than reported for either the above subarctic or temperate lakes. 

 Manganese concentrations in the Barrow ponds are low in comparison to 

 those in the above mentioned lakes, and are remarkable in light of the high 

 correlation usually expected between iron and manganese concentrations 

 (Williams et al. 1971c). This may be due both to differential humic 

 mobilization of iron vs. manganese and to a lack of secondary mineral 

 formation in Barrow pond sediments. Both calcium and magnesium 



