Devil’s Tower National Monument

A Bulge or a Volcanic Plug?

There are two theories about how Devils Tower formed. One theory holds that Devils Tower is a laccolith. A laccolith is a large mass of igneous (volcanic) rock that intruded through sedimentary rock beds but did not actually reach the surface, producing a rounded bulge within the sedimentary layers. The other theory is that Devils Tower is a volcanic plug, or the neck of an extinct volcano.

Like many other mysteries in geology, we do not yet have enough clues to settle the question. But we do know—based on God's record of history in the Bible—that this event must have occurred just a few thousand years ago.

Two-Step Erosion?

Because of the appearance of the surface of Devils Tower and the flat surrounding landscape, geologists believe the surrounding rock layers were washed away in two separate stages. The first event leveled the whole area to the height of the tower (a little above, actually), and the second stage eroded the remaining area into a wide valley, through which the Belle Fourche River runs today.

Geologists do find clues to help them solve questions about the origin of rock formations, but many mysteries remain. The key questions about dating can't be solved correctly without additional evidence from one true account of events back then—the Bible.

By Kevstan, via Wikimedia Commons

Spectacular Columns

Devils Tower is made up of spectacular vertical columns of igneous (volcanic) rock with five or six sides each. At the base, these columns are about 7 feet (2 m) wide, and they decrease in size to around 4 feet (1.2 m) at their peak. The columns are composed of rock with fine-grained minerals that suggest they formed quickly and solidified at a shallow level. The columns of Devils Tower are nearly the same height, which suggests that the whole had once been a single magma pool but had contracted into separate columns as it cooled.

By Tinasuzanne, via Wikimedia Commons

Problems If the Erosion Took Millions of Years

If Devils Tower had been exposed through slow erosion over millions of years, we would not expect to find a tower like we see today. First, the whole formation should have eroded away (it is eroding quickly even today). Second, the formation should have cracked and broken apart due to the constant freezing and thawing each year. Third, the top of Devils Tower would be drastically smaller than its base, as erosion slowly removed more and more of the tower. These logical expectations speak against the old-earth interpretation and confirm the biblical age of just a few thousand years.

By Philkon Phil Konstantin, via Wikimedia Commons