David W. Brown Robert A. Gulbrandsen 1973 <p>Ion activity products for the dissolution of calcite,&nbsp;aragonite, gypsum, monetite, brushite, dolomite, magnesite, hydroxyapatite,&nbsp;and fluorapatite were calculated for a South Pacific guano&nbsp;island brine with an ionic strength of 6.4. Environmental conditions for&nbsp;the brine at the time of analysis and of sampling indicated saturation&nbsp;with respect to calcite, aragonite, gypsum, hydroxyapatite and fluorapatite;&nbsp;a comparison of the ion activity products and equilibrium&nbsp;constants indicated saturation or supersaturation with respect to most&nbsp;minerals found in lake sediments or elsewhere on the island. The results&nbsp;suggest that chemical thermodynamic calculations for brines may have&nbsp;some usefulness despite the many assumptions and estimations that&nbsp;must be made.</p> application/pdf en U.S. Geological Survey Chemical composition of a saline lake on Enderbury Island, Phoenix Island Group, Pacific Ocean article