ALI, ARTWORK, BACKGROUND, CLAY, damouh, DIAGRAM, EARTH, EDUCATION, ENVIRONMENT, EROSION, FORMATION, GEOLOGICAL, GEOLOGY, geostratigraphic, GRANITE, GRAPHIC, GROUND, HORIZONTALITY, ILLUSTRATION, INCLINE, INCLINED, LAND, LAW, LAYER, LAYERS, NATURAL, NATURE, NO-ONE, NOBODY, OF, OLDER, OLDEST, ORGANIC, ROCK, ROCKS, SAND, SCHOOL, SCIENCE, SOIL, STRATES, STRATIGRAPHIC, STRATIGRAPHICAL, STRUCTURE, WHITE,