Figure 20. Stratigraphic columns and paleomagnetic plots at South Mesa, Barnum Brown Amphitheater, and Barrel Spring Arroyo (Figure 4), modified from Butler and Lindsay (1985). Figure shows positions of original paleomagnetic normal intervals (C29n) of Lindsay et al. (1981). Tick marks on left side of columns show levels of original sample sites of those authors; red tick marks indicate sites with normal polarity.