Monday, November 10, 2014

Pedernales Falls

When I read that Pedernales Falls State Park has fossils in the limestone rocks, and the fossils are of crinoids, I knew we had to go there on our Texas trip.  Since Jasper first learned about these sea creatures which closely resemble flowering plants, he's been fascinated with them.  Crinoids are still with us today, in both shallow and deep ocean,  but the abundance of their fossils shows that they were a dominant species long ago.  Limestone is a sedimentary rock which is mostly made of the bones of sea creatures. Since much of Texas was under shallow sea for many long eons, limestone is plentiful.  Limestone exposed and carved into beautiful shapes by meandering rivers has created otherworldly landscapes in the Texas Hill Country, and interesting fossils are quite abundant. These crinoid fossils are thought to have formed 320 million years ago during the Pennsylvanian or Late Carboniferous era. They look more like abstract shapes than any living crinoid because they broke apart into fragments before fossilizing.  It was an unusually hot fall day, following a typically hot summer, and water levels were low. This made it really easy to climb and explore the majestic rocks.  

Crinoid fossils.
Crinoid fossil.
Crinoid fossil.
More crinoid fossils.
This round hole is actually a pothole, created by a trapped rock fragment that spins around when floodwaters push it.

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