What was devils tower

I was talking with a friend and somehow we got on the subject of rock climbing - which eventually led to Devils Tower National Monument. We had an interesting conversation and it turned out that we both had a lot of unanswered questions about the tower.

Devils Tower is located in the northwest corner of the Black Hills, on the Wyoming side of the border. I've been to Devils Tower several times, but apparently, I still had a lot to learn. Today I decided to find out the answers to those questions, because as my kindergarten teacher used to tell me, "If you have a question, chances are the rest of the class is wondering the same thing.

So, in no particular order, here's the lowdown about Devils Tower and the answers to some common questions about the strangely unique landmark. The falling rocks I understand.

But I can't say that I've ever seen a falcon attack a human. In any case, I learned a lot about Devils Tower and hope you did too.

And while it may appear hollow at a distance, the striated monument is actually solid. The NPS compares it to "a bunch of pencils held together by gravity.

Its summit is around feet by feet—roughly the size of a football field—and the circumference of its base is around one mile. Devils Tower is popular among rock climbing enthusiasts, who rely on its many parallel cracks to shimmy their way to the top. Long before modern climbing equipment existed, local ranchers simply made do with a wooden ladder.

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You cannot download interactives. Weathering is the process of the weakening and breakdown of rocks, metals, and manmade objects. There are two main types of weathering: chemical and physical. An example of chemical weathering is acid rain. Caused mostly by the burning of fossil fuels, acid rain is a form of precipitation with high levels of sulfuric acid, which can cause erosion in the materials in which it comes in contact.

An example of physical weathering is wind blowing across the desert playas. Many fossils are found in sedimentary rocks, providing us with clues about ancient ecosystems. The oldest rocks visible in Devils Tower National Monument were deposited in a shallow inland sea.

This sea covered much of the central and western United States during the Triassic period, to million years ago. Dark red sandstone and maroon siltstone, interbedded with shale, can be seen along the Belle Fourche River.

Oxidation of iron-rich minerals causes the red color of the rocks. This rock layer is the Spearfish Formation. As mineral rich water evaporated deposits of gypsum were left behind. During the Jurassic period to million years ago seas periodically retreated and returned. Off-shore clay deposits in deep marine environments became gray-green shales interbedded with sandstones, limestones, and thin beds of red mudstone.

Their origins trace back to sand deposited on an ancient beach, with many outcrops exhibiting preserved symmetrical ripples. Resistant to weathering, these form the nearly vertical cliffs that encircle the Tower itself. Seas retreated and advanced; landforms developed and eroded. New sediments were deposited. Approximately 50 to 60 million years ago, during Tertiary time, tectonic pressures within western North America climaxed, uplifting the Rocky Mountains and the Black Hills.

At this time or shortly after, magma molten rock welled up toward the surface of the earth, intruding into the already existing sedimentary rock layers. What they cannot agree upon are the processes by which the magma cooled to form the Tower, or its relationship to the surrounding geology of the area.

Numerous theories have been suggested to explain how Devils Tower formed. Geologists Carpenter and Russell studied Devils Tower in the late s and concluded that the Tower was formed by an igneous intrusion the forcible entry of magma through other rock layers. Later geologists searched for more detailed explanations.