Sunday, April 1, 2012

Adventures in Fossils Part 1

It's been a while, hasn't it? Too long. Time to return to some new geo adventures that I've had. One adventure that I'm always game for is either rockhounding or fossil hunting. In fact, the best job I ever had was as an instructor at the Pink Palace's world renown Coon Creek Fossil Site. I had an inside on many of the native flora and fauna (give or take an epoch or two) and delighted in hunting for specimens at CC and also at a special Devonian site in middle Tennessee and the once world famous Cretaceous crab site in Selmer, Tennessee that is now covered by a very ugly arse Motel Six. Yeah. That's progress for you.

So this will be a two to three part post where I will display my most treasured fossils, and of course, I'll save the best for last. Let's begin.

These are a few specimens I collected while employed at Coon Creek. One of my duties was to explain to visitors how to clean and display their fossils. You always want to save the matrix that your fossil is embedded within, as that marl is 65 million year old beach sand. The unique feature about Coon Creek fossils is that the entire animal, including shells and bones, have been perfectly preserved within this waterproof aquaclude and you see it pretty much as it was when it lived. Of course, as Coon Creek was on the fringe of the Mississippi Embayment (Fig. 5), all of our fossils there are marine in nature. What you see above are as follows: Crassatella, Culcullaea, Turratella (long and tapered), Drillutra (snail), and ghost shrimp claws.

Above, are various Exogyra (primitive oysters), Pyncnodonte, Ghost shrimp claws and legs, Crassatella, Dentallum, Anteglossia, and a few snails.

The above is one of my most cherished possessions: a near complete crab from the Selmer crab site. The claws are to the left. The rest are halves or legs of those late Cretaceous crabs. This picture does not do these animals' justice.

That object in my hand is a rather large example of the Exogyra oyster from the late Cretaceous. And it's heavy. I have the complete oyster in my hand. They grew them rather large back then. :-)

Skipping over to my Middle Tennessee Devonian site, you can barely make out some of my Trilobites and fish bones. On the bottom left, you can actually make out Trilo-eyes; so far, the only one I managed to find to still have them. 

Various gastropods and molluscs are frozen in this Devonian limestone.

 Another trilobite-big one this time.

 More trilobytes, tube worms, and molluscs.

 Also Devonian, snails, molluscs, tube worms, and snail trails.

 On to California, where I collected these, I cannot tell, but these metamorphosed pieces were once a part of islands that lay alongside a future Orange County and were subducted along with the Farallon plate. These islands were ground up at the plates' edges and spit back to lie on the future shores of a beach. One of these rocks, the light green one, actually belongs with the two below. And their story follows...

And the caption says it all, except that the landslide was so powerful that the rocks from the top traveled halfway up the other side of a facing mountain. They're ugly, but they are some of the oldest rocks in California. 

 The rock on the left... it's volcanic and I found it in the San Gabriel's streambed. I'm still not sure what it is. Any ideas? Hint: it's not basalt. The red rock on the left is a chunk of chert taken from Rainbow Rock in the Santa Rosa Mtns. in the Colorado Desert. I'll post a picture of it's parent rock in a later post. It's huge.
 Garnet Hill is one of those odd places that lies between two faults just north of Palm Springs. The rocks on the series of low hills have some odd qualities, too. The above is one of my favorites due to its texture. It's soapstone and feels waxy to the touch and it's laced with garnets, hence the name of the hill.

Most of the above is basalt, with the exception of the Pyrite embedded in shale and the lapis lazuli in its pure form (2nd rock from the right). These items come from Hawaii, Columbia River plain, and Craters of the Moon Park. 

I have no idea where these two thunder eggs came from, but they were gifts and I certainly have enjoyed looking at them. I'm not sure, though, if I have more fossils than books or vice versa.

Part 2 and possibly a Part 3 next time. And we'll really get to the good stuff. Later!


  1. 65 million year old marl? That places that beach scene around the K-T Boundary? Were those fossils alive just before or just after the event? In other words, are they from above or below the boundary stratigraphically-speaking?

  2. Just before. The marl formed on top of the fossils, preserving a seashore along the Mississippi Embayment. All these animals went extinct prior. And of course, in certain places, there's that iridium layer, but you have to know where to look. ;-)