Rapid change in thickness of beds, due to strong folding.
Amadeus W. Grabau A Textbook of Geology (Boston: D.C. Heath & Co., 1920) 597
TIFF (full resolution)
2400×2048, 920.9 KiB
Large GIF
1024×873, 158.7 KiB
Medium GIF
640×546, 75.0 KiB
Small GIF
320×273, 22.4 KiB