Wednesday, January 04, 2006

Shades of gray

The sun today was occasionally hidden by haze, and my walk in southwest Austin was through a terrain notable for subtle gradations of very muted color--pretty much gray, in other words. I tried to get a photo of a roadrunner, but was foiled by the wily paisano taking cover behind juniper trees each time I had almost focused the camera. But I did get a photo of a mockingbird.


Same mockingbird, different view

Returning along a mountain bike path, I noticed I was walking through a bed of thousands of small fossil oysters eroding out of the soft yellow clay of the Del Rio formation. These specimens of Ilymatogyra arietina range in size from 1/2 inch to maybe an inch and a half in length. They died in the early Cretaceous cenomanian seas and were buried in mud from the volcanic ash of an episode of volcanism in Mexico about 97 or 98 million years ago, and have remained undisturbed until boys making ruts in the dirt with knobby-tired bicycles released them into the sunlight. So here some of them are.

An Ilymatogyra arietina

More Ilymatogyras

Photo of myself, with the Ilymatogyra trail behind me.

This will be my last post for a few days. I will be out of town, to see my sister and to visit the San Bernard National Wildlife refuge on the Texas coast.

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