How is a volcanic neck different from a volcanic pipe?

Volcanic Necks vs. Volcanic Pipes: Peeking Beneath the Volcano’s Skirt

Volcanoes! Those fiery mountains that capture our imaginations. We see the eruptions, the cones, the drama. But have you ever wondered what’s going on underneath all that? Turns out, the plumbing is pretty fascinating. Two key players in this subterranean world are volcanic necks and volcanic pipes. They’re both crucial to a volcano’s life story, but they’re definitely not the same thing. Think of it this way: one’s the active water line, the other’s the abandoned well.

Volcanic Pipes: The Magma’s Superhighway

A volcanic pipe? That’s basically the express lane for magma. It’s a channel, deep underground, that lets molten rock zoom from the Earth’s depths to the surface during an eruption. But not just any eruption – we’re talking about the explosive kind! These pipes are usually narrow and cone-shaped, like nature’s own funnel. And they’re often made of some pretty special stuff: kimberlite or lamproite. These rocks are packed with magnesium, which is pretty cool in itself.

What’s really wild is how these pipes form. Imagine magma bubbling up from way, way down – sometimes three times deeper than your average volcano! This stuff is loaded with volatile compounds, things like water and carbon dioxide. As it rises, the pressure drops, and those compounds turn into gas. BOOM! The magma explodes upwards, creating this supersonic eruption and carving out the pipe.

And here’s a fun fact: some volcanic pipes, especially those kimberlite ones, are diamond treasure chests! Seriously, that’s where a lot of diamonds come from. The eruption blasts away all the rock above, leaving a bowl-shaped hole with a ring of debris around it. Over time, that ring crumbles, filling the hole back up. Talk about a geological rollercoaster! The Udachnaya pipe in Russia is a prime example – it’s a diamond mine.

Volcanic Necks: A Volcano’s Ghostly Grin

Now, let’s talk volcanic necks. Imagine a volcano that’s past its prime. It’s quiet, maybe even a bit worn down by wind and rain. The softer stuff that made up the cone has eroded away. What’s left? The hardened magma that filled the volcano’s central vent – that’s the volcanic neck. It’s like the volcano’s throat, now turned to stone. Because this solidified magma is tougher than the stuff around it, it stands tall, often as a striking pillar of rock. Think of it as a fossilized pipe, a reminder of the volcano’s fiery past.

These necks are made of hypabyssal rocks – fancy term for igneous rocks that cooled relatively close to the surface. Rocks like trachyte or phonolite. They’re fine-grained and sturdy, which is why they stick around for so long.

Now, sometimes, a volcanic neck can cause trouble. If magma tries to rise again, it can get blocked by the neck, leading to a pressure cooker situation and, potentially, another eruption. On the other hand, a really big eruption can just obliterate the neck entirely.

You’ve probably seen pictures of volcanic necks, even if you didn’t know what they were called. Shiprock in New Mexico is a classic – this massive rock formation that shoots up from the desert floor. Or Devil’s Tower in Wyoming, which I remember seeing in “Close Encounters of the Third Kind”. These formations are like geological time capsules, giving us clues about what the area was like millions of years ago. Beacon Rock in the Columbia River Gorge and Devil’s Desk in Katmai National Park are other cool examples.

So, What’s the Real Difference?

Okay, let’s break it down:

FeatureVolcanic PipeVolcanic NeckThink of it as…An active water lineAn abandoned wellHow it’s madeExplosive eruption from deep within the EarthMagma hardening in the vent, then erosionWhat it’s made ofMagnesium-rich rocks like kimberliteTough rocks like trachyte and phonoliteWhere you find itBuried underground, doing its jobStanding tall after the volcano’s goneIts jobTo get magma to the surface right nowTo remind us of the volcano’s glory daysBonusSometimes full of diamonds!Great for photo ops!