This week’s geology picture was sent to me by my friend Phil Plait aka “The Bad Astronomer.” This week’s picture– two pictures, actually– shows the famous K-T Boundary.
Phil explains,
I’ve attached the K/T pic. It was taken in Trinidad Park in southern Colorado, where the boundary is very distinct.
It’s my hand in the 0731 picture. 🙂 0732 puts it in context. The rock above is limestone, and below is coal and other friables. The coal erodes away easily with rain and wind, so it forms that slope, which is murder to climb, like trying to swim uphill. The limestone is much tougher so it forms a cap. As the coal erodes back, eventually the limestone breaks and rolls down the hill. There were big chunks of it lining the base of the slope. All of this used to be underwater a few million years ago.
Thanks for sharing, Phil! I had a busy day with thesis revisions, so I’m posting this week’s Monday picture just in the nick of time… here on the east coast of the USA it’s a few minutes to midnight.
Georneys 
These pictures may be used again when I roll around to K again for my Geology Word of the Week. I think K-T Boundary would be a great post! However, these pictures were too good not to share sooner. It will be awhile until K since I’m at U this week (for those who are not familiar, for my weekly words I rotate through the alphabet).
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As a nitpicking geologists as I am: K/T is an anachronism, as Tertiary no longer exists – now it’s K-P(aleogene) Boundary…only the Quaternary (as most awesome epoch ever) will never, ever be removed from stratigraphy- HA!
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Noted. Doesn’t have quite the same ring as K-T Boundary, though, does it?
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how can i get into Astronomy
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Are there visible areas of the KT (or KPG) boundary anywhere further north in Colorado…say, around Boulder?
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