The sedimentary rocks along the trail between Johnson City and Elizabethton, consist of , from oldest to youngest, the Honaker Dolomite (a modified limestone), Nolichucky Shale, and knox group limestones. They range in age from 542-488 million years and were deposited in a shallow tropical sea on the coastline of Laurentia (North America) when it was located south of the Equator. The limestones and dolomites were formed by the accumulation of countless shells and body parts of animals that lived in these seas. The shale was formed by clay deposits washed off the continent and into the sea.
Sedimentary rocks are generally deposited as flat lying layers on the sea floor but the rocks on the trail are tilted. The tilting occured during the Alleghanian orogeny, a mountain building event that occured about 325 million years ago when Laurentia collided with Gondwana (Africa) creating the supercontinent of Pangea and teh Appalachian mountains. The orogeny deformed the sedimentary rocks casuing them to be tilted, fractured, and faulted. It also recrystallized the limestone destroying most of the originial fossils formed in the rock.
to log this earch cache please answer the following questions. 1. At the listed coordinates study the two rock shelves that run along both sides of the trail, use the sign pictures at the sign near the trail head to identify the type of sedimentary rock that makes up the shelves? 2. Can you see any remnants of fossils among the rock shelves? 3. While not required feel free to post a picture of you and your group at the earthcache.