Gorge Formation for Dummies

A typical gorge

It may seem odd, but some of the most doofus answers at the content farm formerly known as eHow were published on questions that seem so simple a fifth-grader could answer them. In point of fact, some of the answers fifth-graders might have supplied would probably be better than those barfed up by the site's stable of freelance contributors; contributors like wannabe "cryptozoologist" Angela Libal and her attempt to explain "How Gorges Are Formed" at Sciencing.com.

We checked, and our three-time DotD appears to have rewritten an even more incompetent post by five-time DotD Edwin Thomas (aka Richard Thomas), but that's neither here nor there. What is here or there is that Libal sashayed through several hundred words at Encyclopedia Britannica and National Geographic before she synthesized a 125-word "answer." That answer includes some semi-factual information, but... well, let's just see what Angela had to say:

"Rivers carve gorges as they pass over the land by carrying rocks and soil away." – That's selling the process of erosion pretty short, Angela... "The continuous flow of water and abrasion by debris in the water eventually cuts a deep trench through the landscape that exposes many layers of rock." – A geologist would point out that the bulk of erosion in many living gorges is in fact a result of freeze-thaw action. "Glaciers can also dig gorges into the land as they advance and retreat." – Well, no: alpine glaciers can enlarge an existing canyon, but glaciers are pretty lousy at carving what Libal defined as a "steep-sided, narrow valley."

No discussion of gorge formation would be complete without an attempt to explain how a river develops so much power that it erodes vertically with little or no sideways component. At its simplest, river erosion is concentrated in the vertical plane in domains where the gradient is relatively steep; often as a result of local or regional uplift. Here's how Libal explains this situation:

"Vertical uplift is when the edges of tectonic plates rise as they crash into one another to form steep, rocky features, such as mountains and gorges."

This may be Angela's attempt to reword a definition of the term "orogenesis," but who can know? What we do know is that her explanation of vertical uplift is utter bullshit, and completely deserving of another Dumbass of the Day award.

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