“One third of the sea bottom is covered with a soft gray ooze or mud made up entirely of the shells of minute animals which live in the surface waters.”
Charles R. Dryer Lessons in Physical Geography (New York, NY: American Book Company, 1901)
1998×2400, 2.8 MiB
852×1024, 374.3 KiB
532×640, 187.1 KiB
266×320, 58.3 KiB