Ephemeral snow and ancient rock

The entire universe in blog form
Feb. 10 2011 7:00 AM

Ephemeral snow and ancient rock

I love living in Boulder. I have pretty much the same routine every morning: get The Little Astronomer off to school, start my coffee, grab a bowl of cereal (generic brand Cocoa Krispies, which I call Faux-co Krispies), walk across the house to my office, and open the window shade.

When I did this yesterday, here was my view:

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

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Those are Boulder's iconic Flatirons, named for their shape. Their geologic history is fascinating: They're made of Precambrian rock -- 600 million years or more old! -- that was exposed to weathering when the first Rockies pushed up about 300 million years ago. That rock eroded and oxidized, forming red sediment. This was laid down flat and was covered by an inland sea 40 million years later. During the time of the dinosaurs this area became a floodplain, but at the end of the Cretaceous a second uplift began, forming today's Rocky Mountains. This broke through the sediment, cracking it and lifting huge sheets of it nearly vertically: the Flatirons. North of here are similar but much smaller formations, and they aren't raised as vertically. They really give a sense of the uplift and the incredibly slow march of time.

With the Sun shining so brightly, that snow in the picture hardly lasted until the afternoon. It was gone in the blink of an eye, the flap of a hummingbird wing, compared to the lifespan of those formations. The Earth is old, so terribly old... but events on a human timescale are still worth appreciating.