I am by no means a climber, but I love rocks and have a great appreciation for people who choose to spend hours and hours with their faces inches away from rocks. I have climbed a few times, and I really got a kick out of how much attention I paid to changes in lithology, bedding, and grain size (THANK GOD A PEGMATITE!). As someone who pays attention to outdoorsy writing I found myself following the recent (successful) attempt to climb the Dawn Wall of El Capitan in Yosemite. The imagery is amazing at so many scales, the far away views of course but the close ups as well that highlight how pitiful the handholds are that Tommy Caldwell and Kevin Jorgeson both found and used to climb. Anyways, I found myself watching a wonderful Earth Porn video of some of the climb and thinking about another stupendous El Capitan related piece of work that was recently completed. This was a detailed geologic map of El Capitan made and published by Roger Putnam. Putnam also spent hours and hours high above the valley floor studying the rocks, but he also took samples, detailed notes, and compiled all of this work and information into a unique geologic map. Importantly, it is one of the best views we have of what the guts of a pluton look like. That is after all what people are climbing in Yosemite, the different colors and variations in rock type are the result of complex magma chamber processes happening miles underground over geologic time scales.
Well, in honor of the climb, the Geological Society of American announced a sale on the geologic map today, and I thought it would be useful to mention them both. Enjoy!
Screenshot of the geologic map of El Capitan from a great National Geographic piece with a sliding map feature.
Apparent Dip 