18,500 ft... above Zebra Rocks, a wonderful expanse of the mind,
and if the weather is just right, it reveals an almost “Martian-like” topography. Conversation slows, words have a heavy gravity, a pulse exists within every step,
and purpose dictates action. -But the surreal state I was in kept me centered on simply just walking and keeping pace. I couldn’t wait to share photos of this geological landscape with Erin, @erinedonaghy...so in her own words: ————-
“Zebra rocks are named for their striped appearance. The white rocks are felsic igneous dikes that are associated with the McKinley granite. The black rocks are Cretaceous marine siltstone and shale that were metamorphosed to argillite when the McKinley granite intruded...
So the pluton in this diagram would be the McKinley granite. And the Dikes would be the felsic intrusions at Zebra rocks. You can see the red rocks (the igneous intrusives) cross cut the “country” rock, or the in-place sedimentary rocks. The heat from the intrusions metamorphoses the adjacent sedimentary rocks, so in the case of Denali, the mudstones turn to argillite
Through time, and continued faulting and uplift, the pluton and some of surrounding country rock have been brought to the surface and uplifted into the mountain Denali is now
So the “roof pendant” would be the sedimentary rocks that managed to get preserved on top of the pluton despite the massive erosion and uplift the region endured
Note how the dikes cross-cut the sedimentary rocks, and sills and laccoliths are bedding-parallel” - -GEOLOGY POW!!!
Her words are as deep and beautiful as her soul ...geology at this altitude is as intriguing as the unknown that lies ahead... : @mountainclimbgrace : 1.Leading slowly towards the “football field” with summit ridge in distance 2. Above Zebra Rocks, Archdeacons tower to climbers left, with wind plumes on summit 3. “Thumbs Up” is all it takes ———————————————-
@alaskamountaineeringschool #climbalaska @denalinps