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Gels composed of sodium-aluminum silicate, Lake Magadi, Kenya

January 1, 1968

Sodium-aluminum silicate gels are found in surficial deposits as thick as 5 centimeters in the Magadi area of Kenya. Chemical data indicate they are formed by the interaction of hot alkaline springwaters (67° to 82°C; pH, about 9) with alkali trachyte flows and their detritus, rather than by direct precipitation. In the process, Na2O is added from and silica is released to the saline waters of the springs. Algal mats protect the gels from erosion and act as thermal insulators. The gels are probably yearly accumulates that are washed into the lakes during floods. Crystallization of these gels in the laboratory yields analcite; this fact suggests that some analcite beds in lacustrine deposits may have formed from gels. Textural evidence indicates that cherts of rocks of the Pleistocene chert series in the Magadi area may have formed from soft sodium silicate gels. Similar gels may have acted as substrates for the accumulation and preservation of prebiological organic matter during the Precambrian.

Publication Year 1968
Title Gels composed of sodium-aluminum silicate, Lake Magadi, Kenya
DOI 10.1126/science.161.3837.160
Authors H.P. Eugster, B.F. Jones
Publication Type Article
Publication Subtype Journal Article
Series Title Science
Index ID 70011520
Record Source USGS Publications Warehouse