equatorjournal: Tad Nichols, Kharga Oasis, 1974. “Concretions on the rim of the Kharga Oasis depress
equatorjournal: Tad Nichols, Kharga Oasis, 1974. “Concretions on the rim of the Kharga Oasis depression in the western desert of Egypt were formed by: ground water in an Eocene limestone. They remained after the crumbling rock in which they had been embedded had weathered away. Their surfaces are deeply etched by sand blast. (Tad Nichols: Western Ways Features) From “The earth beneath us” by Kirtley Fletcher Mather, 1975.https://www.instagram.com/p/CVioy8NN8Ay/?utm_medium=tumblr -- source link