Saturday, September 08, 2007

Akron Rocks

I went on a geological tour of Akron this morning. It was free and began at Lock 3 as part of Homegrown Saturday Farmers Market. It was a pleasant and unique way to look at our city. I took some photos and will present them as a quiz for local residents. Can you guess where these rocks and stones are located around the city? I'll give you an image and a brief description of the rocks in question. All information here was obtained from a free guidebook handed out to us as we got on our trolley to begin the tour. The booklet was written by Joseph T Hannibal of the Cleveland Museum of Natural History and is titled "Building Stones and Cultural Geology of Akron: A Short Walking Tour." Our guides for the tour were a paleontologist and geologist from the University of Akron. They had plenty of magnifying devices with them for kids and adults to examine the stones at the granular level.

This is an example of local sandstone from the Sharon Formation, a layer of sandstone and conglomerate underlying the high points of Akron on Broadway and High Streets. The old quarry was located at the site of the current Key Bank Building on Main St.

Here is an example of granodiorite, a rock with a slightly different composition from granite and it was quarried in Quincey, MA. The dark color is due to minerals such as dark gray feldspar and ferromagnesian minerals. It originated as magma and is more than 320 million years old.

This is another sandstone called Berea and it was obtained from Deep Lock Quarry in Peninsula. In it can be seen pebbles and clayey clasts.

The marble used to carve this piece is the same type used by Michelangelo to sculpt his Pieta and David. Called Carrara marble, it was quarried in the Italian Apuan Alps. According to the handy guide booklet, we find that this marble was the "result of metamorphism of a pre-existing limestone during the Jurassic Period, between 200 and 145 million years ago."

The oldest rock on our tour comes from Canada. It has a commercial name of Caledonia granite and is a billion years old. Contemplating it, I immediately felt like an insignificantly temporary collection of cells in comparison.

This beautiful floor pattern was created out of pink limestone from the Holston Formation of eastern Tennessee and the black limestone came from either New York or Vermont, Both stones originated as sea sediment in the Ordovician age and are over 400 million years old.

I really perked up my ears when I heard we would be seeing cephalopods in the next batch of rocks. Thanks to my favorite science blog, Pharyngula, I've become enamored of these beautiful creatures. Look closely and you will find fossils of large conical cephalopod shells in this gorgeous gray and pink limestone.

Come back tomorrow, and I'll post pictures of the actual sites where the above rocks and stones can be found.


Delco Dem said...

granodiorite- is that located at the building south of Market on Main? I believe that there was a McDonalds there? It looks oddly familiar

jeffox said...

Hiya VG! I saw your posting at Pharyngula.

Nice blog, nice post. That 1 by-old granite is comparable with the "Duluth complex" granite/gabbro in northeastern MN. I have a few photos of samesuch on my blog at "Da Fox Hole" under the "Fool for the City" entry. You are welcome to stop by and check it out, if you'd like.

Oh, and I know that Akron rocks. Isn't that the original home of Joe Walsh? :)

Village Green said...

Joe Walsh used to play in Kent when he attended university there, but he wasn't from Ohio. I think he was in a band called The Measles before the James Gang, but I can't tell you for sure -- that was so long ago!

Thanks for stopping by!