Desert Pavement

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Okay, it's true I'm a geologist, and I'll cop to seeing the world through senses shaped by a geologic perspective. But don't think this is an apology for that perspective. Quite the contrary, I feel extraordinarily fortunate to have that influence superimposed on my otherwise human views.

Here's an example. I'm at a ballgame at AT&T stadium and the seats are packed with thousands of fans representing the enormous diversity of the Bay Area. From where I sit high up in the stands the throng looks pretty much look alike. Of course I know differently.

And then, suddenly, I'm on a field trip to Death Valley, high up on a hill looking out over a broad valley covered by a field of rocks. They were washed down from the surrounding hills by streams and rivers. From where I'm standing they all look pretty much the same, but the rocks reflect the diversity of their source material, the bedrock underlying the hill surfaces. And, indeed, they do, being composed of chunks of igneous, sedimentary and metamorphic rocks, sandstones and shales and granites and lava. The surface is called desert pavement and the similarity in colors is termed desert varnish. The rocks look alike, but we know they are different.

It's the same with the fans at AT&T Park. They all look pretty similar. But I know they are uniquely different, reflecting their origin and history going back generations. When we study the geologic history of Death Valley, we take that geologic history into account, explaining the uniqueness of the rocks and surfaces. How much richer would our appreciation of the diversity and uniqueness of the viewers in the stands be if we took the time to appreciate their distinctive histories?

Sometimes we can learn a lot from geology.


With a Perspective, I'm Ray Pestrong.

Ray Pestrong is an emeritus professor of geology at San Francisco State University.