My heart sister Nicole often posts writing prompts at her blog, The Coffee-Stained Writer. I normally don't go in for writing prompts, but one day, long ago in blog years, she posted this writing prompt, and I think you'll soon see why I couldn't resist:
Choose a word from the list below and write for five minutes without stopping, beginning with that word as the subject of a sentence. If you get stuck, repeat the last word you wrote over and over until you can pick it up again.geologymobilehomelessmarker
Geology has taken over my life to such extremes that, watching a true crime show the other night, the first thing I noticed in a photograph wasn't the soon-to-be-murder victim, but the rock formation she was standing in front of. Sheeted dike in weathered granite, perhaps? Obviously a desert environment. Interesting. I wished the murderer (who was posing as a fashion photographer to lure his victims) had put it a bit more in focus so I could tell. The cops wanted to know where this photograph had been taken, and hared off into the California desert to see if they could locate it. "Ask a geologist!" I screamed at the teevee.Geology's taken over my life.My house is filling with rocks. Pebbles from streams, rivers, lakes and oceans, deserts, mountains, and gravel roads. My cat's even fallen prey to the geology bug and lies upon my sample card of minerals, which is on the couch. When I get blocked, I turn to my rocks. I turn them over and over in my hands and try to listen to their stories.The first thing I notice about scenery now isn't the pretty plants or animals or views. It's the geological formations. Geology dictates things as varied as earthquake survival and the New York City skyline. Geology, my friends, is important.
I stumbled across this post again, and decided that as that had been such fun, I should not only show it to you here on Rosetta Stones, but also do more five-minute geology! So I asked my Facebook friends for words, downloaded a timer on my phone, and got busy.
From Karen Corey: Rift Valley
Rift valleys are probably one of the most incredible geologic features on the planet. We are talking continents pulling apart, people. Plate boundaries diverging! I remember being mightily astonished as a young 'un to learn that the Great Rift Valley in Africa was basically a new ocean being born.
They contain some of the most spectacular waterfalls on earth: you haven't seen much of anything until you've seen water falling over a rift.
Then you get the under-the-sea rift valleys where great gouts of basalt spill out and create new crust. I mean. Honestly. How many other places on earth can combine the best of earthquakes and volcanoes in one neat package? With bizarre critters evolved to live in some of the least hospitable terrain on the planet. If you want to be even more boggled, all you have to do is realize that all life may have started in these rift valleys under the sea.
One of my favorite rift valleys on earth, of course, is in Iceland, where you can see two plates diverging without having to pay a heck of a lot for a submarine ride. A midocean ridge on dry land, people. Marvelous.
I think we need to talk more about rift valleys around here. It's on my enormous list of topics to tackle. Stay tuned!
From Garry Hayes: The Spokane Floods
Okay, geez, I get it. Y'all want to talk about the Spokane Floods (Also known as the Missoula Floods). I don't blame you. We're talking water on a mind-boggling scale changing entire regions in a flash flood. So. Yes. It's on my list, and we are going to talk in depth about them at some point in the nearish future. It could even be our next installment in the Catastrophe Series once I get off me duff and finish Mount St. Helens.
I even have in my posession a book by a creationist who thinks the Missoula Floods are some government conspiracy, and I'll be reviewing that book, which will be immense fun for us all.
For those who don't know what the Missoula Floods are: back during the last Ice Age, the ice sheet that loved to travel down from Canada to the United States would periodically dam the Clark Fork River in Montana. We don't know how often it happened, but it was at least dozens and perhaps hundreds of times. Water would back up pretty far and create a magnificent glacial lake, because ice sheets make an efficient barrier to water.
The problem is, ice floats. And while ice over a mile thick is pretty darned heavy and won't float in, say, a bathtub, eventually the lake would get deep enough to float the ice. When the ice floated, it broke. And all that pent-up water went rushing out across Montana and Washington. You can see where it gouged canyons, scoured the landscape, left gigantic ripple marks, and more. It ran out all the way to the Pacific Ocean, changing the landscape all the while. It's incredible - and more incredible when you realize all that water was basically following the path of molten rock from millions of years before.
So yeah, we are going to have a lot to talk about, and it'll be one heck of a ride!
From Nikki Gilbertson by way of her daughter: Bedrock
Bedrock is the best rock! Okay, pretty much all rock is best rock in my eyes, but bedrock is super important. There's a reason why it stands as a metaphor for really important, foundational truth.
Bedrock is what we like to build on. If you can build your city on bedrock, it'll stand tall and strong. If you look at New York City, you'll see what a difference bedrock makes. All of the famous skyscrapers, some of the tallest in the world, had to be built on bedrock. Those parts of the city where the buildings aren't so tall? It's because we couldn't reach bedrock to build on, so we couldn't reach for the skies.
Bedrock can be right on the surface or buried miles below, depending on what's been going on geologically in the area. Seattle's got a super neat example: there's a fault that runs through the city right about where the I-90 is. South of that fault, the ground has dropped and the bedrock is buried under miles of soft sediments left by glaciers. North of it, the ground has been uplifted, and the bedrock is right near the surface, sometimes exposed. We get pretty excited by exposed bedrock here in Seattle, because it's so rare to see it! Most of it was covered up by all the debris the ice sheets dropped.
Bedrock can be made of just about any kind of rock. I've seen all kinds: sedimentary, igneous, and metamorphic. I've lived on bedrock formed by ancient seas, and bedrock formed by young volcanoes, and bedrock formed by mighty mountains.
Bedrock is cool. We should talk about it more!
And that's all the five-minute geology for today. But this was a super mega amount of fun, and so I don't doubt we'll be doing it again! If you have a word you want to see me do some five-minute geology about, please feel free to email it to me at email@example.com. Be sure to put "Five Minute Geology" in your subject line so it doesn't get lost.