Devils Tower

Devils Tower National Monument(NPS site and the Wikipedia article) is a massive tower of igneous rocks in eastern Wyoming (apparently I have really wanted to talk about Wyoming recently), very close to the border with South Dakota. I have personally been there, photo left is from my trip there during the summer of 2007, and I must saying standing look up toward to top of the tower really makes you feel insignificant. This area is sacred to the Native American tribes (see here) in the area and is a climber's dream, they only allow a limited number of climbers a year (see here) and seeing the climbers up against the sheer rock surfaces really makes you realize just how huge it truly is, you probably get the idea that it is huge by now. The formation of the rocks themselves are very well understood so you can imagine my surprise when I saw this on the left hand side of Conservapedia:

"Atheists have no plausible explanation for Devils Tower, which sits in a plain like a watch found on a beach."

Couple of things about that. First Atheists are not the ones studying the geology of Devils Tower, that would be geologists. I personally know plenty of geologists that believe in God. But beyond the semantics and wording of the statement geologists do have explanations for the formation of Devils Tower, if you have ever been to the visitors center at the site you would know (or just been to the NPS site). In fact the idea that it was formed by Igneous rocks pushing up through the older sedimentary rocks has been around since the late 1800's. Effinger (1934) summarizes this discussion well:

Carpenter (1888) interpreted Devils Tower to represent a volcanic plug, being the duct through which the subterranean magmas passed to higher level in the earth's crust. Russell (1896) proposed the name plutonic plug for the intrusive bodies of the Black Hills, stating that they differ from the laccoliths described by G. K. Gilbert (1877) in the fact that the molten rock did not spread out horizontally among the stratified beds so as to form "stone cisterns", although some of the hills not thoroughly examined by him might reveal this structure with further study. "As they are composed of igneous matter forced into sedimentary strata and have a plug-like form, it will be convenient to call them plutonic plugs." Devils Tower is believed by him to represent an extreme type of plug, the part now remaining being an erosional remnant, where the arch of stratified rock which once surmounted the summit of the mass has been completely removed and the surrounding strata eroded away.

This pretty much means that it is an igneous rock and may have the same source as many of the other igneous mountains in the area. Effinger (1934) summarize the origin of Devils Tower as such:

From a consideration of the evidence presented it would seem most reasonable to believe that Devils Tower represents a remnant of a laccolith, probably rather small in comparison with others of the Black Hills, and separate from the Laccolith of the Little Missouri Buttes. It would seem probable that the duct through which the igneous material was injected lies beneath the tower or the talus. The stages in the formation of Devils Tower according to this hypothesis might be represented diagramatically as is shown in the succeeding charts.

Several more years of study lead to Robinson (1956) saying:

Much more detailed geologic work will have to be done in the surrounding area before the mode of origin of Devils Tower may be proved conclusively. The evidence gathered during the present investigation, however, suggests that Devils Tower is a body of intrusive igneous rock, which was never much larger in diameter than the present base of the Tower, and which at depth (1,000 feet or more) is connected to a sill or laccolith type body. The bases for this theory are—

1. The exposed portion of the Tower is the result of recent erosion. At the time of its intrusion it was surrounded and probably covered by several hundred feet of sedimentary rock.

2. The mineral composition and texture are more typical of shallow intrusive rocks, which are formed at depth, than extrusive rocks, which are formed on the surface.

3. No evidence of extrusive igneous activity has been found in the surrounding area.

4. Missouri Buttes, about 4 miles to the northwest, and the Tower have the same composition so it is assumed that they were derived from a common magma; possibly the magma of a large intrusive body, such as a laccolith or sill.

5. In a well drilled about 1-1/2 miles southwest of Missouri Buttes, near the center of a structural dome, rock similar to the Tower and Missouri Buttes was encountered at about 1,400 feet below the base of Missouri Buttes. Inasumuch as the thickness of the sedimentary rocks in this area is normally much greater than this depth, the rock in the drill hole probably represents an intrusive body, rather than the Precambrian igneous rocks upon which the younger sedimentary rocks were deposited.

6. The relatively small amount of talus, slope wash, or terrace gravel derived from the Tower and Missouri Buttes suggests that they have not been extensively eroded, and therefore the original igneous bodies were not much larger than at present.

7. Columnar jointing is common in intrusive bodies formed at comparatively shallow depths.

But wait these paper says that there are still questions as to the origin of Devils Tower. Yes in a way, we know it is igneous and we know how it got to where it is so when I think origin this is what I mean but the main question right now is did this igneous rock reach the surface and form a volcano (Effinger, 1934; Robinson, 1956). In other words we know what Devils Tower is and how it got there, but we don't know if it reached the surface, far from a question of origins.

So I figured I would check to see what the Conservapedia article of Devils Tower said to see if maybe there was further explanation. The relevant part of the article reads (click here to read the version of the article from the date I read the article, 8/28/2010):

There are two implausible atheistic theories about the origin of Devils Tower:

one theory is that it was formed by molten igneous rock forcing its way into the area's sedimentary rock, cooling before reaching the surface, and the sedimentary rock being eroded away.[2]

the other theory is that Devils Tower is the remains of a volcano, though no other evidence of volcanic activity has been found in the area.

Both theories are baseless and absurd because there is no extrusive igneous activity in the area, and there is no evidence of volcanic activity in the area either.[3]

Intelligent design explains the rock well: it is a work of art worth seeing.

Hey look those are in fact the two competing ideas for what happened during the formation of Devils Tower. My question is how does not finding extrusive igneous rock near by invalidate both hypothesis? No extrusive igneous activity would tend to lead to the first theory you stated that the magma did not reach the surface. The only thing is that area that was the surface at the time has since eroded away which could lead to the possibility of the magma as having reached the surface but it is something we will most likely never know for sure, although maybe there is a more recent paper that I didn't find that has settled the debate. I also don't see how a rock monolith shows intelligent design but I will agree with them on one thing, this National Monument is definitely worth going to see at some time. I'll leave you with one more of my pictures this time of the talus pile at the base of the tower.


Sources:
Effinger, W.L., 1934, A report on the geology of Devils Tower National Monument: National Park Service, Field Division of Education: Berkeley, California

Robinson, C.S., 1956, Geology of Devils Tower National Monument, Wyoming: U.S. Geological Survey Bulletin 1021-1

Both papers can be read online if you want to read the whole thing Effinger (1934), click on contents on the left hand side, and Robinson (1956), click on table of contents on the bottom of the screen and from there you can navigate to any part of the paper. I found them thanks to this site which has a list of papers published about many of the National Park Service entities.

National Park Service Series