C.
D.
Younger Paleozoic formations
Formations of the remaining Paleozoic systems are likewise of interest because of the ways in which they differ from those already described.
Figure 38. Distinctive features of Cambrian rocks.
A. Algal heads in the Park Shale Member of the Gros Ventre Formation. These calcareous mounds were built by algae growing in a shallow sea in Cambrian time. They are now exposed on the divide between North and South Leigh Creeks, nearly 2 miles above sea level!
