Glaciers and Granite, the Dummy Version

Real glacial striations

Some freelancers have to work at saying stupid stuff, others come by it naturally. The first are those who perform their "research" with due diligence and then make a complete hash of the information they've found. The second are people who just write what they (think they) know. It's sort of the difference between being a dumbass on purpose and being a dumbass by accident. The first kind is probably worse, but anyone who contributes to the stupidification of the internet is fair game for the Antisocial Network. That's why today's contributor is a HubPages type who calls herself womannshadows (real name Susan Berger), here seen holding forth on "Why Rockport (and the rest of Cape Ann) is so Rocky."

Susan's contribution to dumbing down her readers is this little paragraph: "The granite of the Cape Ann peninsula is extremely dense and perfect for quarrying, the evidence of which is a large part of the areas [sic] history. The unique density of the granite is because of the pressure from sedimentary rock that once covered the bedrock.  As the ice sheet eroded the sedimentary rock 15,000 years ago, it brought the granite close to the surface"

We're not sure where Berger got the idea that the local granite's density is "unique," though it's a safe bet that years of exposure to the misuse of the word means she thinks it just means "unusual." She also misuses "density," too, for that matter... but the two biggest mistakes Susan makes are that 1) granite crystallizes from a melt, and the mass of the overburden contributes little if anything to its texture. That includes its density, both the actual definition and Berger's usage. 2) Glaciers didn't scrape off the sedimentary rocks to expose the granite here. It's exposed at the surface because it's in a basement block that was uplifted along the boundaries of a rift -- the rift that ultimately became the Atlantic Ocean.

We'd be remiss if we didn't point out that Susan's images, though artistic, also contain misinformation: the last image's caption calls the lines in granite boulders "striations." Those aren't striations, they're joints — and they have nothing to do with glaciers. You can tell they aren't striations because they cut through the rocks instead of being only on the upper exposed surface.

Don't let misinterpretation and misinformation be your guide to science. That's why we're here, handing out the Dumbass of the Day to writers like womannshadows. Sorry, Susan...

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