Weekly Gem #242, Verified sightings of a lost creek
Location: This Hidden Gem is located about a mile upstream of ‘the beaver pond.’ It’s a lost creek, which has chosen to remain lost, so that’s as specific as we can be about its location.
Although the creek is camera shy, we discovered that if you take pictures of vivid green moss, or the fall colors, or a fallen log, the creek allows you to include it ‘in the background.’
The canyon through which this creek flows has quite a story to tell. It rises about 1500 feet above the creek, and even from a distance you can see the horizontal lines. Those lines are from layers of sediment that settled on the sea floor, in a sea that was nowhere near here. First off, I think we can agree that there was no sea at 7,000 feet elevation. By definition, this sediment was at one time below sea level, and has gradually risen with the surrounding mountains by at least a mile and a half.
But there was a lot more movement than that. Think yo-yo on a geologic time frame. Before rising this mile and a half above sea level, the sea floor sunk 8 miles, to a depth where lava flowed and pushed and wedged. See that whitish diagonal in the cliff? That’s a ‘dike’ of this lava, which forced the rock apart miles underground, and refused to leave as the sea floor rose to its current heights.
Now, about that yo-yo. There are dikes in this sea floor from different dips below the surface. The most recent rise was with the Rocky Mountains, which has only been happening for the last 60 or 70 million years ago. This sea floor formed 1.3 billion years ago, giving it time to rise to the surface, then dip down for a few miles, then back, and forth, 10 or 20 times over the course of its ‘life.’
Not only has it moved up and down, it’s traveled the earth in ways that are hard to imagine. The super continent Pangea came apart beginning about 175 million years ago. Pangea assembled from earlier continents about 335 million years ago. So this hunk of rock floated along, presumably on the North American tectonic plate, through the formation and separation of as many as four different Pangeas!
The ‘end’ of the story happened in one of the recent ice ages, when a glacier ripped through the rock, exposing this geology so we can see it … and creating a place for a nice little creek (if you can find it).