Migration of Chemical Elements in Sedimentary Environments (3) -Chemical aspects of natural waters in Limestone areas (1) -

摘要

For the study of the life of Limestones (sedimentation and diagenesis of Limestone), it was tried to clear the origin of chemical elements of natural waters in Limestone areas. All HCO, ions of all samples and all Ca^2 ions in almost samples are supplied from calcium carbonate, Ca^2 + ions 1ess than one fifth ,of total Ca^2 + ions in a part of the samples were supplied from other origins except calcium carbonate and sea water. All CI - ions in all samples were assumed to be supplied from sea water. Almost Na + ions in the samples containing over 80 mg/1 of CI ions were assumed to be originated from sea water, but a part of Na+ ions in the samples containing under 80 mg/1 of C1- ions (OKINAWA CHUBU and NANBU areas) was assumed to be supplied from other origins except sea water. All SO^2_4 ions in most samples were assumed to be supplied from sea water, but a part of SO^2_4- ions in samples containing under 80 mg/l or C1 - ions were assumed to be released from Limestones. All K ions in most samples were assumed to be supplied from sea water, but a part of K+ ions in a few samples were assumed to be supplied from human activities. The origin of almost Mg^2 - ions in some samples was assumed to be sea water. In some samples, Mg^2+ ions supplied from carbonates correspond to a little part of total Mg^2+ ions in the samples. The values of Ca^2+/Mg^2- in waters, in this report, are lager than 3.5 - the calculated value of Ca^2+/Mg^2+ in waters which equilibrate with solid phases consisted of calcite and dolomite. The behavior of Na - ions and C1 - inos against Ca^2+ions in Limestone areas ( a concentration of Na+ and Cl - ions in natural waters from these areas is 20- 100 ppm) was related to the origin of these elements.