Chemical analysis using EPMA has been carried out on several minerals sampled from East Antarctica with special reference to secondary minerals. Results are summarized as follows:
In the Balchenfjella region, eastern part of the Sφr Rondane Mountains, East Antarctica, most of the secondary minerals are proved to be pure gypsum crystals, although they take various forms from place to place, for example perfectly-formed gypsum crystals, finely-stratified board-like gypsum, mushroom-like crystals and so on.
In the northern part of the Balchenfjella region, desert varnish is defined to be composed of crystalline jarosite mixed with amorphous silica and to be formed by solution of surfuric acid which ascends by capirally action through very narrow cracks within the inner fresh region of a gneiss rock. This solution of surfuric acid is probably supplied from underlying ground. It is sometimes observed that these crystals of desert varnish work to open the crack within the inner region of rock, futhermore, causing the rock disintegration. This fact is noticeable to consider the mechanism of salt weathering under arctic dry condition.
Varved clay sampled from the fluvioglacial valley of the Mt. Riiser-Larsen area, Amundsen Bay, Enderby Land has also been examined. It is clearly defined that great amount of vivianite was contained within the varved clay. Phosphatic acid which is necessary for the vivianite formation may safely be said to have been provided from droppings of bird such as Pygoscelis adeliae and Catharaota maccormicki.