Lava Types for Dummies

Lava types to a geologist

One of the hallmarks of content-farm freelancers is the ability to scoop up great quantities of information, omit anything they don't understand, and dump the remaining information into a post full of misinformation and half-correct babble. Take, for instance, Hassam from HubPages, who's already demonstrated his ignorance of things scientific three times for us. Well, we've brought him back for a return engagement; this time to take a look at something he called "Types of Lava."

We asked our staff geologist to explain what the phrase "types of lava" would mean to someone with a rudimentary understanding of the science. According to her, the phrase should refer to the composition of the melted rock – rich in silica like rhyolite, poor in silica like basalt – but if you really want to get "down in the weeds," you'd want to talk about differences in mineralogy. For instance, a tholeiitic basalt is one that's rich in calcium plagioclase. Yeah: deep in the weeds! Hassam, on the other hand, wants to talk about the texture of the solidified lava...

Hassam opened by explaining that

"Lava is a molten rock released during an eruption by a volcano with the liquid flowing wide and large distances before cooling and solidifying. The eruptions produce mixtures of volcanic ash and other fragments called tephra." ...which is a bad start: volcanoes that produce "wide and large" lava flows are basic, and generally produce limited amounts of tephra compared to acidic eruptions (e.g., rhyolite). Whatever the case, Hassam provided no details of lava composition and fails to mention the chemistry of the melted rock at all; i.e., basaltic lavas are generally melted oceanic crust; rhyolitic lava is melted continental crust.

No, Hassam thought "types of lava" referred to the texture of solidified lava; waxing poetic about admittedly cool words like aa and pahoehoe (Hawaiian words for blocky- and ropy-textured basalts), and "pillow" as he did nothing more than reword a Wikipedia entry.

Well, we're sorry, Hassam, but those are not "types of lava," those are textures of solidified basaltic lava. Just as non-scientists (especially self-described skeptics) mistake the word "theory" for "guess," Hassam has used the common word "type" incorrectly. We're tired of scientific illiterates doing that, so we're giving Hassam yet another Dumbass of the Day award for his scientific illiteracy. So there.

copyright © 2017-2022 scmrak

SI - VOLCANOES