Limnología química de las lagunas pampásicas (provincia de Buenos Aires)

Abstract

The pampasic «lagunas» from Argentina are homologuized with lakes of third order (without stratification). Following the Venedigo’s system, based on salinity, most of pampasic lagunas are oligohaline and some others mesohaline till some oases of extreme hiperhalinity. The Aguesse’s classification is applied with some modifications, based on promedium aud annual fluctuations of salinity. Using the graphic system of Maucha, 1932 each body of water is typified by the relative amount in milliequivalents by litre of Ca, Mg, K, Na, CO, CO, H, Cl and SO. The annual variation is allways conspicuous. The conclusion is that pampasic «lagunas» are peculiar by the high content of Na, Cl and CO,H, the fluctuations of SO, and Mg, and the varied ratio Mg/Ca, which don’t correspond with the postulations about fresh water habitats, and varied from 0,16 to 3,73. The relation Ca -|- Mg/Na -|- K is also very variable, but is characteristic for each body of water; allways the figure is minor in summer, surely by the increasing of Mg. The organic matter varies between 17 and 21 p. p. m. and is amazingly constant the year around.