Tag Archives: ancient sea

A Geologic Tour

Dr. Jim Derby is a geologist who has taught at the University of Tulsa and worked in the petroleum industry. He knows a thing or two about rocks.

He gave me a tour of the geology around his house. The cool thing is you can find similar features in the rocks at your home…fossils, traces of long dead organisms, maybe even some dino droppings.

A Coral Reef in Tulsa

A 20-minute drive (give or take) can take you 300-million years into the past. Redbud Valley Nature Preserve is a fantastic place to take a walk and learn about the area’s geologic history. Hundreds of millions of years ago eastern Oklahoma was covered by an inland sea. The water helped create this amazing geology.

Redbud Valley has a nature trail that winds through a woodland area and small prairie but the best part is the Bluff Trail. According to Susan Carr, a naturalist at the Oxley Nature Center, the cliff is made up of two layers of rock that date to the Pennsylvanian age which lasted from about 318-299 million years ago.

Redbud Valley Nature Preserve

The upper layer of the rock, according to Carr, is about 12-feet thick. You don’t have to look hard to see a lot of holes. Those holes are called Vugs and indicate that this area was once home to an ancient coral reef.

Redbud Valley Nature Preserve Redbud Valley Nature Preserve

Along the cliff face you’ll find rock that’s older than the coral reef. This is a layer of shale. It’s formed when minerals such as quartz, mica, or pyrite settle at the bottom of a body of water. The minerals mix with decaying organic matter in the mud. The pressure builds, lots of layers form, and the mixture eventually become rock thanks to a process called lithification.

Redbud Valley Nature Preserve Redbud Valley Nature Preserve

Who says time travel isn’t possible?!? I can’t even get my mind around how long it took to form these rocks. Geology is simply amazing.

Redbud Valley Nature Preserve is open Wednesday through Sunday from 8am-5pm. It’s a great place to spend the afternoon (unfortunately, dogs are not allowed).

Susan Carr will host a Geology walk on Oct. 19th, 1:30-3pm.




Fossils in your backyard

(a note from Dan- This has been updated with a  few changes from the original. Special thanks to Dr. Jim Derby for helping me clarify a few things.)

So you’re thinking, ‘Man, fossils are cool but I’ll never see them in Oklahoma.’ How about a fossil hunting trip to south Tulsa? Leake Park has dozens of gigantic stones that are used as barriers. Nearly everyone of them are home to roughly 300 million year old fossils. The rocks were once the bottom of an ancient seabed that covered Oklahoma from the Cambrian through the Devonian Period.

The fossils include Crinoids, an animal that attaches to the sea floor and filters food as it comes by. The Crinoid fossils are either small and round with a hole in the middle or you can see the stem.

Other fossils include ancient clams and Brachiopods. Brachiopods live on the seafloor. They kind of look like clams but they’re different animals. They use a stalk-like device to anchor themselves to the bottom of the ocean and just wait for food to float by (kind of like me when I’m watching football). The fossils at Leake Park are sea shells from ancient sea and they’re right here in our backyard!!! They’re not sexy like a T-Rex but I highly recommend a fossil hunting trip of your own, it’s a great and simple way to introduce kids to the wonders of fossils.

Rock barrier at Leake Park Top of rock covered with brachiopods More brachiopods DSC_0150