That’s a cobble of quartzite from the Potomac Formation gravels (Cretaceous aged deposits) exposed along the northern side of Piney Branch valley in northwest Washington, DC.
Some of these cobbles come bearing a load of Skolithos trace fossils:
So that’s likely to be the Cambrian-aged Antietam Formation. But we didn’t come here for the Skolithos. We came for the artifacts. These quartzite cobbles were quarried by Native Americans and used as the base material for sharp tools and implements. The quartzite breaks with a conchoidal fracture, and you can find many “worked” cobbles at this site, showing multiple intersecting conchoidal fractures. Here’s one:
This results in the production of copious flakes of quartzite:
The famous ethnologist William Henry Holmes studied this site in the late 1800s, and his work is still quite accessible and enjoyable to read.
And here’s another worked cobble, with an annotated copy following immediately to show the numerous sites were six different flakes were knocked off:
Where trees have fallen over, their roots bring up samples of both source pebbles/cobbles and anthropogenic flakes:
Another tree; same situation:
This site is on a bland-looking hillside, less than a hundred meters from the busy thoroughfare of 16th St. NW, above a nasty-looking (and smelling) stretch of urban stream. It’s a treasure trove of prehistorical archaeology, though hardly pristine. If you visit, remember not to remove any of the artifacts you find – please leave them there for other folks who want to connect with the very different world of the pre-colonial past.
Hello, I came across your site looking for information about the geology in northern Virginia (Fairfax, Arlington, Falls Church, etc). I really appreciate the information presented.
One of our sons took a course of yours and loved it! That was about four years ago at the Annandale Campus. He told me about your site – but I didn’t tell him I had already found it.
He’s now in Tucson doing History at University of Arizona.
Thanks for putting “it” out there with all of the construction and development surrounding the Beltway.
Anne S.
Thanks for the kind comments!
I have found, too many to count, similar stone artifacts with very detailed layered pictograph markings, along with elaborate complex scenes. Some etched into the stone, others painted or dyed images and many both. Each stone shape has been worked into animal profiles, some having 3,4,5, and 6 different animal and human heads. They often take close examination to discover, while others are obvious. In my opinion they are amazing works of art. I don’t show many people my collections, because I’ve seen very little documentation about this sort of Native American Art. I’m happy to see I’m not the only one who has been blessed to discover such a special history.
We pulled up old azaleas in our front yard in Highland Springs, Virginia last fall. We have found two cobbles with trace fossils, as well as different flakes in the same area. They must have been embedded in the deep roots that we dug up and since that time the rocks have surfaced. Has anyone found any others in this area in Virginia? I wonder how old these rocks are! They look like the ones you have shown.
If they have the trace fossils, the cobbles are from the Cambrian Antietam Formation, so somewhere in the span of 541 (+/- 1) million years ago – 485.4 (+/- 1.9) million years ago.
I’ve been finding many multi tools along with multiple faces on rocks. They all have a flat spot and as u turn them around many other faces appear.
I would like to comment on Nates observations of native stone/pebble/rock art of the past millenniums. I live on what I believe to be a ceremonial grounds. I literally have areas of fish, bird, face, snake, mammoth, Buffalo, mineralized corn, squash and beans seeds and remnants of wooven baskets in the heavy clay dirt. Many of the effigies have multiple animals and faces depicted on them. I find them so fascinating and cannot believe arrowhead hunters skip right over them. Interpreting them is like becoming proficient in a foreign language. It constantly bewilders me at the quantity and the skill of the artist that created these effigies so long ago. I have millions of them on my average of every different type stone and mineral and have even found some well preserved wood effigies.
Wow! @NotJust ARock
That is amazing! How blessed you are to have such interesting ancient history nearby, as well as the knowledge & ability to appreciate the s you find. I think it is incredibly fascinating and love that there are others out there who share similar passions. If you don’t mind, what area do you live in? I live in Oklahoma and find a ton of neat pieces like arrowheads of course, but also ancient tools and some fossils. Your heavy-clay type diet sounds like ours here in OK. Do you have photos up of your finds? They sound so interesting!!! What are the baskets like? It’s amazing how some of the items can remain in such great condition, despite all the time and elements. Any way, take care and happy hunting! 🙂
I am very interested in this chain. Over the past year, I have been studying the same images and what I believe is a language pinned on “fundamental geometry” on many stones here in Oregon. Is there anyone studying this on a professional level that would be willing to engage in dialogue on this topic? I have reached out to a couple of archaeologists but need a bit more direction as to who if anyone is pursuing this study. Any help is greatly appreciated. G. Hausler
Q: How when you go up a trail like this or Soapstone Valley do you tell anthropogenic flaking from natural breakage?
Callan, do you have an approximate time period or year range when the Piney Branch quartzite tools would have been made? Thank you.
I do not; sorry!!
I have found all the above in the dirt where new homes are being built on old farm land in estacada Oregon..many hidden in layers of dirt. a lot of spear head type of arrows..and hammers and axe heads both hand held and once was tied to something and blades and nutting stones and possibly one used to start a fire with a stick…I thought at first it was my imagination getting away with them resembling the different tools…but I know without a doubt that I have found some real tools…and a bird effigy for sure. .once the houses start going up everything gets covered over and someday someone will realize what some of them are….,artifacts
Omg!!! I would give my left leg to be able to go to these places you speak of before and after any ground breaking your company does.
Lithic Artifacts 3 to over 7 ft. deep , Fire Pits in original Wisconsin age gravels under 7 feet of topsoil . Enjoy https://www.facebook.com/dennis.wallace.353250/photos , https://www.facebook.com/dennis.wallace.353250/photos_albums