Complex sentence: The Terraces were formed by geothermally heated water containing large amounts of silicic acid and sodium chloride regularly spouting from two larger geysers of a group of 40 smaller geysers in the nearby area.
Split into simpler sentences: The Terraces were formed by geothermally heated water containing large amounts of silicic acid and sodium chloride regularly spouting from the two large above mentioned geysers. These two geysers were part of a group of 40 smaller geysers in the nearby area.