They also undertook to examine the true nature of that system of parallel ramparts discovered on the moon's surface by Gruithuysen, a learned professor of Munich, who considered them to be "a system of fortifications thrown up by the Selenitic
engineers." These two points, yet obscure, as well as others, no doubt, could not be definitely settled except by direct communication with the moon.
(2008b) documented the widespread occurrence of evaporite calcitization, sulfur ore mineralization, and secondary gypsum (selenitic
textures) crystallization that indicate that karst development in the region is dominated by hypogene processes where ascending, transverse speleogenesis is associated with both water and light hydrocarbons that have created complex secondary diagenetic alterations within the Castile Formation.