Fairly the again yard.
Lengthy earlier than I grew to become a avid hiker, I used to be drawn to the spectacular limestone bluffs on the northwestern fringe of the Little Rockies. After I taught in Harlem 40 miles north of right here within the mid-1980’s my spouse and I sometimes visited mates on their ranch a mile north of the cliffs. Lastly in the future I walked to the bottom of the cliffs and located my option to the high. It instantly grew to become certainly one of my favourite locations. Since popping out of retirement in mid-December 2019 to show in near-by Hays, I’ve been capable of stroll alongside the cliffs a number of occasions.
What’s up with these tilted slabs?
In case you’ve ever pushed southward throughout the Fort Belknap Reservation on a summer time night because the tilted slabs of limestone are catching the late-day daylight, you perceive the attraction (see picture beneath). What hiker wouldn’t wish to rise up there and take a look? On my three most up-to-date visits to the cliffs I took a number of drone pictures – These, together with many different pictures, diagrams, maps, and Google Earth photos are included within the picture tour. I’m not gonna lie – there are some actually good pictures within the tour, so it gained’t harm my emotions for those who go there now. Nevertheless, if you wish to know why there’s a wall of limestone across the Little Rockies, proceed studying.
I’m fascinated with the scenic panorama of the Fort Belknap Reservation, in order a science instructor I’ve realized as a lot as I can concerning the geology of the realm. Right here’s what I do know concerning the wall . . . The cliffs are manufactured from almost vertical layers of Madison limestone, fashioned from sediment that was deposited in the course of the Mississippian Interval about 320-360 million years in the past. Thick deposits of corals, shells, and different types of calcium carbonate accrued on the ground of a shallow tropical sea when this a part of Earth’s crust was a lot nearer to the equator. The Madison limestone makes a serious contribution to the surroundings of Montana – The Gates of the Mountains, the Rocky Mountain Entrance, Lewis and Clark Caverns, Sluice Bins, and Bighorn Canyon are all manufactured from (totally or partially) Madison limestone.
The remainder of the story.
The sediment was deposited in horizontal layers, finally grew to become rock, and was lined by youthful layers, which additionally grew to become rock (sandstones and shales). Then about about 60 million years in the past magma labored its method towards the floor, inflicting the layers to be domed upward. The magma hardened, turning into the igneous rock discovered on the core of the mountain vary. The doming occurred in an space about 15-20 miles in diameter. Over time, a lot of the limestone and different layers above the igneous intrusion eroded away, leaving solely the steeply-tilted fringe of the limestone dome that varieties the cliffs proven within the picture and different related outcrops across the perimeter of the Little Rockies. Hey! Thanks for sticking with me! Now go benefit from the picture tour. 🙂
Beneath: This map marks hikes which have been featured on bigskywalker.com thus far, together with a number of in Glacier Park – Choose full display to develop, zoom in for extra element, or click on on a marker for a hyperlink to the put up.