Today I went with Dr. Ignacio Pujana and a group of people from UT Dallas to visit various places around the Dallas/Fort Worth to learn about the geology of the Metroplex. I’m not geologist at all but I do find geology interesting, especially the geology of the area I live in. Being somewhat familiar with the geology of your area helps you understand why a lot of things are the way they are. It impacts how houses are built, how roads are formed, the type of industry your area supports, people’s hobbies, and so many other things.
We made 5 stops around the Metroplex to sberseve in person the various major geological features that are around us. It was an overcast autumn day that was a bit cold. That didn’t deter this from being a great educational trip.
Here is a illustration of the various geological layers that are in the Metroplex.
Stop 1: Mosque Point – Fredericksburg Group Layer, Walnut and Paluxy Formations
Our first stop was Mosque Point in Fort Worth. Here we observed the Fredericksburg Group layer. Dr. Pujana pointed out how the latter is made up of Sand Stone which is clearly visible in that area.
We the followed a fisherman’s trail through the woods to a site of pretty waterfalls and interesting natural elements. This was at a much lower elevation. Here we observed how this entire area was on a bed of sand called the Paluxy Formation or Trinity Sands.
Stop 2: Eastchase Parkway – Washita Group Layer, Grayson Marl
For the Washita Group Layer we pulled over to observe the Grayson Marl formation. It was visible right from the side of the road. This is one of the least exposed layers in DFW. It was made up of soft sand that was full of tiny fossils of sea life.
Stop 3: Rockledge Park, Lake Grapevine – Woodbine Sandstone Layer
Next stop was at Rockledge Park at Lake Grapevine to learn about the Woodbine Formation. On the north area of the lake the Woodbine Sandstone layer is very visible. Here fossils are also found. in 1982, Julie Tyler found Hadrosaur, a dinosaur, tracks while walking her dog. While we were there, we also got to come across a couple fossilized dinosaur tracks. The size of them is incredible.
Stop 4: Super Fiesta Bazaar – Eagle Ford Shale Layer
This stop was one of my favorites because it was so new to me and I was surprised how easily accessible all these layers are. It also fascinated me how the Eagle Ford Shale was visible right behind a shopping center off of Loop 12, a road I have driven on many times.
The shale is primarily comprised of fossilized organic matter. It’s almost like a solid form of oil. I couldn’t even fathom how much life had to exist and die in order to create so much shale that it’s an entire layer in Texas. When you pick it up, it just crumbles in your finger tips.
Stop 5: Anderson-Bonner Park – Austin Chalk Layer
This is the last stop we made and it was great last visit. We went to Anderson-Bonner Park in North Dallas to view the Austin Chalk layer. I had actually been there many times and in that area many many times. I had to idea what Dr. Pujana showed us existed.
He led to the creek area in the back of park and down a small steep trail. Once down there incredible cliffs of white chalk lined the small creek. I had no idea that all that white rock was chalk. I also amazed by how beautiful it looked. I took a lot of photos while down there.
I really enjoyed this trip and I learned so much about geology and the metroplex. It all opened my eyes impact geology has on everything around us. I appreciate Dr. Pujana taking us on this trip.