Northern Virginia Triassic Success At Long Last

[patelinho7]

I cannot believe I’m writing another trip report so soon, let alone for another track, but here we are! A couple weeks ago, I wrote a report on the Lower Cretaceous Patuxent Formation tracks I had found. I spend much time exploring the Cretaceous of mostly Maryland by way of the Lower Cretaceous Potomac Group and also the Maastrictian Severn Formation. I enjoy learning and exploring those formations very much, but my main area of research is on the Culpeper Basin of Virginia, as some of you may already know. 
 

The Culpeper Basin is the northernmost Upper Triassic/Lower Jurassic basin in Virginia, part of the Newark Supergroup. I live in northern VA, so this is the closest fossil-bearing strata to me. The only problem is that the VA basins are largely unexplored, and the Culpeper Basin is by far the least known. Not only has it been largely untapped, but it is far more difficult to collect than the other basins. It doesn’t produce often, and when it does, it’s fairly random. There are no localities in this region of the basin so far that regularly produce high quality Triassic fossils, as some of the other Triassic basins on the East Coast do.

 

However, like I said, this is the closest fossiliferous formation to my house, and I always wanted to fulfill my dream of finding fossils “right in my backyard”, which I never anticipated being possible until the last couple years. What makes my search even more difficult is that much of my scouting, field work, research, and informal mapping has been in the Fairfax County/Loudoun County area, the northernmost part of the Culpeper Basin in VA. Most of the success in the basin has occurred farther south, in the far reaches of the aforementioned counties as well as beyond them. I am hunting a very unknown, difficult part of the basin because it’s closest to home and easy to scout on the average day. I frequently visit sites on the way back from errands.

 

Many of you already know of my relationship with Dr. Rob Weems. I met him initially because of my various Patuxent footprints but much of our meetings have been geared towards discussing the Culpeper Basin and he has been invaluable to me in learning the stratigraphy and paleoecology of the region. I started my research and pursuit of fossils in the Culpeper Basin over a year and a half ago based on stories mentioned by him. I was so inexperienced at the time with research methods and my understanding of geology. For months, I would visit sites I thought could have been productive and find nothing, largely because I didn’t know what I was doing. It was very frustrating, and I am ashamed to admit that it made me want to give up on the Basin. I remember my mother asking how my research was going and I told her that I thought the Basin was “uncollectable and not worth spending any more time on. Maybe I would come back to it after a long break.” Well, I did get that break, I wasn’t able to spend any time researching the Basin this spring during my busy semester at school. I think it gave me the time I needed to take a fresh start, because this summer, I hit the ground running!

I decided I wanted to start researching the Basin again, but with a far better approach. I told myself that it didn’t matter what I found or didn’t find, I was learning for the sake of educating myself on the local stratigraphy and potentially adding to the collective knowledgebase of the Culpeper Basin. This approach gave me far greater patience for any empty-handed returns from field work. In a way, it has become my own research project on the side. I began re-reading the literature I had found in the past year, literature that documented many previous finds and conclusions, primarily from the previous century. As it turns out, scientific literature never ceases to teach you new things over repeat readings. Either that, or I’m a terrible reader and I missed crucial details. I started making important revelations regarding the local stratigraphy and started visiting some old sites and some new with a fresh set of eyes and mind. Instantly, I began to have success. I found some naturally occurring exposures, which are very rare in the area due to development. I started to notice lithological differences I never realized before, so I could tell exactly where I was in the stratigraphic column. I started to finally find my very first fossils, which were all plant material. These finds set the stage for my recent success. 
 

I will take a moment here to mention that I have finally understood what goes in to finding your own sites the hard way, from start to finish. When I joined this forum, I was told (and read) about the process of finding your own sites through lots of research and the satisfaction one gets when it finally pays off. I’m finally experiencing that satisfaction! However, the battle is not won. I have chosen a really difficult region to search, and the finds are often random and uncorrelated. I can’t stop here, I have to continue so I can find more.

 

The Culpeper Basin houses several local members of the Passaic Formation. One such member is the Balls Bluff Siltstone. This is the only member of the Basin that offers the chance to find bone material. I was hooked by the possibility of finding bones here in N. VA, and I have focused most of my research on the Balls Bluff. Following old discoveries from literature, I selected a few areas that would logically expose the Balls Bluff and possibly yield bones. One such location was the site of very recent development that has just about finished up. The development has left a lot of Triassic red bed material scattered around the banks of a creek and wetland area. I found this locality over a year ago because of the development and obvious presence of Triassic rock but never found anything. I revisited the locality at the beginning of the summer, searched more carefully, and found this: 

 

 

This is the impression of a cycad leaf with two possible trace marks above and below (the upraised ovals). It was a significant find for me because I hadn’t found anything legitimate from the site till now. But it was an interesting discovery because this is actually not the Balls Bluff. This rock shows a thinly bedded luster-y smooth surface showing trace fossils. This is more likely to be the Groveton Member of the Culpeper Basin, known for its footprints and other trace fossils in frequently mud-cracked red beds and thin grey shallow lake strata. This was rather far East for a significant presence of the Groveton, but still possible. I thought it was odd but didn’t think much of it.

 

Fast-forward to this past Friday. I unexpectedly had an afternoon to kill on my own and it was a mild weather day, quite surprisingly. I went back to the locality for the first time since early June  when I found the above fossil. I have been busy, so I had been studying a few sites closer to home. But with the free afternoon, I took the chance to revisit this locality. Previously, I had been searching the northern reaches of this wetland area, closer to the main road and where I parked. I had the thought to push further south along the creek just to see what was there, and thank goodness I did.

 

I was immediately greeted with this sight:

 

 

Exactly the red material I was looking for. Perhaps there may be some larger rocks nearby to look through.

I got closer and started to see washes like this: 

 

I thought this may be a promising area to search for bone material, but I started to notice lots of thinly bedded rock:

 

 

These rocks are clearly that Groveton-type track/trace preserving strata. There’s a lot more of it here, clearly establishing the presence of multiple lithologies more than a few anomalies. It seems I found access to a whole layer disturbed by past development. You can see the usual suspects of this bedding surface present on these two pieces. The raindrops or possible burrows are there on the first piece, and sedimentary structures are there on the second. You are welcome to speculate on the second piece, however. I couldn’t conclusively make out any tracks but I thought it looked odd. I didn’t collect it, so hopefully it’s nothing.

 

I made my way to the top of the wash and scanned the ground and my jaw dropped. This is what was peeking out of the ground looking up at me:

 

 

(It came from that hole but I forgot to take a true in-situ picture so I placed it back down)

 

Surely that HAD to be a track, right?! You can clearly see three stubby toes. The mud was obscuring a lot of the surface, though. I had to make sure that the dirt wasn’t playing tricks on me. I needed to get down to the creek and wash it off. I clambered down through the reeds and across unstable rocks to the water’s edge, splashing my hand in to wash off the rock. I spooked a little bass that came shooting out from under the rock I was standing on. Better a bass than a copperhead lurking between the rocks (though I did get a tick on me later). Slowly, a full shape emerged:

 

 

It was glorious. I couldn’t believe I’d done it! I wasn’t even expecting or trying to find tracks. Apparently, I’m magnetically attracted to them. Anyone who knows the Triassic basins of VA knows how random these tracks can be. It’s a gamble, you have to be in the right place at the right time, and I finally lucked out! 

Like I said, it wasn’t the bones I was looking for, which means I still have more work to do. But it was an exciting find that I’m super happy about. It also means there may be more tracks lurking around my area, something I never anticipated. Here are some more photos:

 

 

 

 

 

 

I am thinking this is probably Grallator ichsp., but it is obviously weathered and partial. I reached out to Dr. Weems to see what he thinks and will update the thread accordingly.

 

Anyway, I’ve really been enjoying this one because it’s my first Triassic dinosaur fossil and so close to home at that. I don’t often get to relish a find from beginning to end. I hope this is a sign of even more success to come in the Culpeper Basin and hope it can serve as an inspiration and sign of recent success for others searching the Basin. Thank you for reading!

Edited July 23 by patelinho7
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[shark57]

Nice footprint! I'm sure Rob Weems will be excited to see it. Hopefully you can loan it to him, then I can see it in person.

[Jeffrey P]

Great find and lots of work to find it. Congrats and thanks for sharing your story. 

[Titan]

Thanks for sharing and congrats on the great find! 

[Newbie_1971]

Congratulations man! Way to go! I am sure you are super happy!

[automech]

"It was glorious."

That, sir, is an understatement. If you hollered out your excitement, I'm sure I would have heard here in Calvert County. Very happy for you.

[Carl]

Outstanding outcome! Bravo on the effort and the fossil!

[EMP]

Awesome find! I’m glad to see all of the hard work finally paid off! 

[Mikrogeophagus]

Nice work! Love seeing underappreciated formations get their fair shake. Hope the Triassic continues to deliver for you!

[Fossildude19]

Great job! Nice find, for sure. Congratulations on your success!   

[patelinho7]

Thanks everyone! It is nice to hear such kind words from so many of you. 

[Fossil_Adult]

Congratulations man! And then there was two. This is one of the most difficult formations to collect. The amount of places you must go to, and strike out on, to come across something like that?!? Wow. I think I’d have a heart attack if that was poking out. 
 

On another note, I’d too love to get into contact with Weems if possible. Because if you say your track came from the Groveton, so did mine. It might be good to map out where these two sites are to Weems so he can connect the dots. Anyways it’d be cool to run into ya one of these days, I’m sure that’ll happen being that we are collecting around the same area.