Inspired by the #GatewayFossil hashtag on Twitter, I’m reposting this piece that I originally published at “Updates from the Paleontology Lab” on June 9, 2009.
My first exposure to fossils in the field (as opposed to in a museum) occurred when I was around 5 years old.
When my father was a teenager he used to hunt with my grandfather in the mountains along the Botetourt-Craig County line in western Virginia, where he had casually noticed some fossils in the stream gravels (I’m not sure he knew at the time what they were). My mother has always had an interest in rocks and fossils (due to the influence of her grandfather), so my dad used to take us up to that area to look for fossils. We mostly found molds of crinoid column segments and occasional brachiopods in a brown sandstone (above). With the limited resources available to a relatively poor child growing up in the country at that time (no internet!), I didn’t know much more about those fossils, and doing my college work in Minnesota and Louisiana I never actually learned much about the rocks I collected in my youth, a point that was emphasized with the discovery last year of the Boxley stromatolite in Bedford County (where I grew up).
Now that I’m back in Virginia with years of geologic training behind me I can look at these rocks in a new light. Last Friday, my father and I spent the day driving around Botetourt and Craig Counties, looking at rocks. Near Webster, VA we stopped at a railroad trestle close to the Blue Ridge Fault, with deformed Cambrian Rome Formation exposed in the trestle foundation:
These rocks are from the Devonian Chemung Formation (apparently redescribed as the Foreknobs Formation). They are tilted nearly 90 degrees, which is especially clear where the rocks intersect with the road (the lines leading toward the truck):
According to the Geologic Map of Virginia the mountain where Dad’s house is located includes both the Rome and Elbrook Formations (both Cambrian); I think this rock may expose the contact between them (with the Elbrook being the lighter-colored limestone at the top).