A Weekend Yorktown Trip to Surry County, Virginia (Feat. Some Cambrian Guests) 8/11/23-8/13/23

[Echinoid Express]

Hello everyone! I had the opportunity over the last weekend to visit a spot in a campsite along the James River that had an outcropping of Pliocene Yorktown Formation fossils, as well as some "visitors" from the Cambrian Swift Run Formation of the Blue Ridge Mountains of Virginia. This was my first hunting trip that was outside of North Carolina, which was really exciting for me! While it was miserably hot and humid, and I had a stomach affliction for the duration of the trip, I made the best of it and found some really cool fossils, and met a lot of interesting folks. In all, over 70 people from various organizations were there. I have quite a few pictures to share, so hang in there with me!

 

These are a few photos of the area on the river. The area we were in was brackish, and the camp beach there was recently worked on, which limited some of the fossils in the immediate entrance area. However, further down either side there were a lot more fossil piles. It was neat being able to look up and see all of the shells exposed on the cliffside.

 

 

These huge chunks of material containing tons of Chesapecten scallops and other fossils were found in several areas. They were more plentiful before the beach replenishment from my understanding

Fortunately there was not anything dangerous encountered over the weekend, but plenty of little critters were out and about. (Especially ants!)

 

The hunt went from Friday evening to Sunday morning. On my way out on Sunday, I was given a lift back to my vehicle by a kind family from the Richmond Gem and Mineral Society, who were also nice enough to lead me to a well-known tulip poplar tree on the site. This massive tree is over 400 years old, and it takes about 8 fully grown adults hand-in-hand to fully encircle the base of the trunk.

Now, on to the goodies I picked up. The majority of the fossils I picked up were varying sizes and species of Chesapecten scallops. I looked really hard for an intact echinoid or an Ecphora murex, but unfortunately I didn't get that lucky! As for the Chesapecten species names, and that of several other fossils as well, I am still in the process of learning them, so my detailed information will be lacking. I'll stick with my best finds, but this is a little group of mostly Chesapectens I had laid out while organizing my finds.

Here are a few Chesapecten I had that had some variable colors, including my largest three specimens. They measure just over 15.25 cm (6 inches) wide. They have been brushed with water to show the color better.

These are some random fossils I found including two coral fragments, several gastropods, some partial tube clams and some loose bivalves.

This is the largest venus clam I found in the hunt, around 7.6 cm (3 inches) wide. These typically held together better than a lot of other aragonite-based shells.

I found a few intact bivalves in a section of the cliff that had slid down to ground level, but most of them were so fragile due to their aging aragonite that they broke apart upon handling; some even had the physical consistency of the sand surrounding them! These are some ones I found that stayed intact to some degree, and one that had mostly broken away. While they're not the prettiest specimens, I realized they could be used as a cool visual example of how steinkerns form. I'll have to find a way to stablize them a little better so I can get them in a display box.

 

While most of the bivalves were very brittle, some had undergone a mineral change and had their aragonite replaced with calcite. They give off a faint greenish-yellow glow in UV light, which made for a fun late night activity! One man even found a cluster of calcite crystals from the formation! Here are two intact calcite clams, and two loose calcite shells I found.

 

This was a rather sizable Crucibulum limpet I found, also referred to as a "cup-and-saucer snail". It's a little over 3.3 cm (1.3 inches) at it's widest.

 

This was the widest barnacle I found during the hunt, and it's over 5 cm (2 inches) wide.

Here are a few barnacle clusters I found that had some nice pinkish coloration preserved on them.

Here are a few intact oysters I found. The smaller one had quite the barnacle attached to it!

 

Someone at the hunt suggested that this particular bone fragment was possibly avian. There were a lot of whale bone fragments around the site, and there have been some pretty sizable speciments found there, including whale vertebrae and whole dugong ribs.

This ray tooth fragment was the only fish fossil I found myself during the whole hunt. One young woman found a 2 inch mako tooth, while another woman found a fairly sizable megalodon tooth.

Jumping back to my Chesapecten, This is a medium specimen that had some very large barnacles on it (perhaps Balanus concavus?) They're probably the longest ones I found, measuring around 5 cm (2 inches). 

Here is a cluster of some very small Chesapecten.

This is a fairly colorful specimen with some equally colorful barnacles attached to the exterior surface.

Here is one of my largest specimens of Chesapecten (15.25 cm / 6 inches) next to my smallest specimen (1.525 cm / 0.060 inches).

These are some pathological Chesapecten I found, although I'm not 100% sure about the third one, it might just be damage.

 

 

Now on to my top favorites, this is a cluster of small to medium Chesapecten I found. There are some tusk shells on the interior side, and there is a Discinisca lugubris brachiopod on the right side exterior.

This large Chesapecten has a calcite-replaced clam valve right on the rim of the shell. I had found this one on Friday and I didn't learn about the presence of the calcite replaced shells until Saturday, so it went unnoticed until I was washing it at home. I was too busy admiring the huge scallops everywhere!

While I didn't find any intact echinoids there, I did find this oyster shell that has a small fragment of what appears to be from a regular echinoid on it, but I'm still not 100% sure.

I also found this  Chesapecten that appears to have a sand dollar fragment attached to it. Given the age and formation this might be a Mellita aclinensis fragment.

A whale tooth fragment I found on Friday. A boy found a whole one there just before I arrived, and it was over 5 cm (2 inches) long.

Now, we're down to my absolute favorite finds of the weekend. Here is a whole Chesapecten jeffersonius with both valves in fairly pristine condition. There is only a very minimal amount of hard buildup on the valves.

 

 

I also found this specimen, but unfortunately it had a hole through one valve. Still really cool though!

These are cobbles that contain Skolithos trace fossils from the Swift Run Formation, which is an Early Cambrian rock formation in the Blue Ridge Mountains of Virginia. They would break off during the upheaval of the mountains and eventually get carried in water currents all  the way to where they were found in the current age. These are the oldest fossils I've found myself to date.

And last but not least, here is a fairly pristine Chesapecten jeffersonius(?) valve I found with some good color. However, the most interesting part of this one is that there appears to be something in the resilifer of the shell, almost like shiny red nacre. This is the only one I picked up over the weekend with this feature. I wondered if it could be a preserved ligament, but I was a little unsure; I figured this would be the best place to possibly get some insight on it for the moment. The exterior was brushed with water to show color better.

 

That's all for now! I've got a family trip to the southern NC coast planned soon, so I might try to swing by Holden Beach and nab another batch of Cretaceous fossils while it's still producing a lot. I'm also hoping I can find some local Triassic material before the holidays, I've got a few promising leads on some spots, including one right down the road.

-Tony

 

 

 

[Tidgy's Dad]

Quite a nice variety of creatures. 

Even some scaphopods. I rather like scaphopods. 

Thanks for sharing, very interesting post. 

[grandpa]

Looks like a load of fun.  Thanks for bringing us along.