Showing posts with label geology. Show all posts
Showing posts with label geology. Show all posts

Wednesday, April 7, 2010

Round and Round in the Circle Game


May the circle be unbroken.

I found this graphic on my computer today while I was looking for something else. I suspect I saved it a few years back when I was writing about global wildlife migrations and the fact that everything is connected, left to right, up and down, all over the world.

Yes, migration is about more than birds. It includes whales, sharks, tuna, seals, wildebeests, elephants, turtles, pronghorn antelope, butterflies, dragonflies, and even senior citizens going to Florida for the winter.

Of course, the circle game is bigger than that isn't it?

The nuclear molten core of the earth is a bubbling cauldron of magma, and that magma is seething up and cooling down, like boiling water in a pot.

Even as the molten rock goes up and down, it slowly pushes the vast plates of the earth around, and on top of these massive plates of super dense rock floats "the light stuff" like granite, dirt, sand, redwoods, elephants, and us.

And, of course the great nuclear ball that is the sun heats up the oceans which have massive upwellings of water at the equator, and massive downwelling at the poles.

These in turn drive vast ripping ocean currents we call the Gulf Stream or Humboldt's Current, or the Indian Ocean Gyre, and these in turn determine where the fish feed and whether we need to throw another log on the fire in December.

Several times a day the gravity of the moon pulls billions of pounds of water this way or that, driving water backward up rivers, fueling tidal bores, and pushing waves up and down a million miles of crab-speckled beaches.

The atmosphere too boils up and cools down, with massive upwellings and downwellings of air, and vast ripping currents of wind driving themselves around the earth in clear patterns we call the Air Stream or the Trade Winds or the Doldrums, depending on where they are and what they are doing.

The ground we live on also boils with life as worms and groundhogs, ants, plants and fungi, turn over the soil and build upon it, pulling things down and lifting things up.



And on top of this boiling planet we fight the change.

We try to build for permanence and prevent extinctions.

We fear both global warming and global cooling.

We worry about energy and where we will get it.

We are upset when butterfly, bird, mammal and fish migrations change, and we are equally upset when they do not, and the animals pass away in the face of changing circumstances.

As a rule we are oblivious.

Elephants now live in the heat of Africa and Asia, but their cousins once roamed the frozen north, and we do not think to wonder why none are there now.

Birds fly overhead unseen, coming from places we do not wonder about, and going to places we cannot imagine.

We do not know the name of the drainage we live in, or how the creek behind our house makes its way to the ocean.

We do not even know the names of all the trees in our backyard.

Meanwhile, we go to work in our prisons on the road, stuck in traffic, insulated from the weather, our minds spinning; the world's longest playing record, all the grooves running to the great self-obsessed hole in the center.

“EfĂ© children of the Ituri Forest in Zaire (Rep. of Congo, central Africa) begin the Osani game by sitting in a circle, feet touching, all connected. Each child in turn names a round object like the sun (oi), the moon (tiba), a star (bibi) an eye (ue) and then goes on to name a figurative expression of “round” like the circle of the family, togetherness, a baby in the womb, or the cycle of the moon. As players fail to come up with a term that is “circular” they are eliminated from the game. Eventually, only one remains. Tradition has it that this player will live a long and prosperous life.” :: source
.

Saturday, January 5, 2008

Terriers, Trilobites and Plate Tectonics




The 1888 New York Times article about groundhogs and shale deposits that I posted earlier this week, reminds me that the geology of this part of the U.S. has quite a bit in common with parts of the United Kingdom.

To be sure, a great number of things on the surface are different, but if you scratch below the surface of the soil, you will find "It's a small world after all."

I am not the first person to notice.

As early as the 1860s, scientists in Wales noted that the trilobite known as Paradoxides davidis, occurred in both Wales and the Northeastern seaboard of the U.S. near Newfoundland.

The odd thing -- the "paradox" that gave the Paradoxides genus its name -- was that this shallow water trilobite was separated from its identical brethren by a thousand miles of deep ocean. How could that have occurred?

Paradoxides trilobites were not the only thing that occurred in fossil beds separated by thousands of miles with no connective geological tissue to be found between. How could this have happened?

Around 1915, Alfred Wegener of the University of Marburg in Germany, suggested a bizarre explanation for which he was roundly ridiculed: that the continents drifted around like icebergs on the ocean, with the the lighter granite and dirt of the surface continents slipping and sliding on the harder and denser basalt that lay below.

Wegener was a little vague as to what forces were propelling the continents -- he suggested centrifugal force, or perhaps a lunar pull similar to that which raises the tides. One thing he was certain of, however, was that continents did move about.

In the 1950s, the U.S. began to systematically map the ocean floors incidental to planning for submarine warfare. The systematic mapping of the world's oceans revealed two phenomenon unknown up until that time; the presence of a world-wide system of mid-ocean ridges, and the presence of deep trenches along the edges of what appeared to be geological "plates."

In 1962, U.S. geologist Harry Hammond Hess postulated that sea floors were spread by magma pumped out of mid-ocean ridges, and that a counter-vailing trend was going on in the deep ocean trenches where the earth was being pulled back into the core through a process of subduction.

In essence, Hess said, mid-ocean ridges produced new material, while the deep trenches consumed old material.

According to Hess, the earth was essentially on a long slow boil fired by atomic energy being released at the core of the planet, with the continents more-or-less-floating like congealed scum on top of a soup of magma.

With Hamond's explanation and Wegner's theory, the table was set for Dr. J. Tuzo Wilson of the University of Toronto to postulate the unifying theory of Plate Tectonics to explain why parts of the U.K. and North America shared identical fossil beds.

Wilson suggested that the United Kingdom and America had collided into each other some 500 million years ago as the Iapetus Ocean, a precursor to the modern Atlantic, closed up. As a result of that collision, the Appalachian Mountains were pushed up, along with the mountain ranges of Wales and Scotland. Because these mountain ranges are made up, at least in part, by the folded remains of the same strata, they share some of the same characteristics and fossils.

Between 200 and 60 million year ago, however, the continents drifted apart again thanks to the addition of new material from the mid-Atlantic ridge.

The new split between the lands masses was not perfect, however, and as a result parts of Wales remain attached to Newfoundland, and parts of America remain attached to Scotland.

So what does this mean for terrier work?

Perhaps not much, but it does suggest things are not so different from one side of "the pond" to the other. That said, while I have moved a lot of crumbled slate and shale while digging on the terriers, I have yet to find a trilobite. Apparently, they are a rare find in the U.K. as well.

What is not rare in my area are groundhog holes with slate and shale-littered spoil piles like the one pictured below. Imagine dozens of these in your farm field, each of them with tunnels beneath, and heavy harvesting equipment driven above. No wonder farmers want groundhogs gone; it's can be a matter of safety as well as commerce.

When folks from England, Wales, Scotland and Ireland came to the U.S., they found a country not all that different from their own, at least geologically. Not for nothing does is "Highland County" Virginia called Highland County!
.
And, as one recent immigrant huntsman to Virginia told The Fauquier Times Democrat, the piedmoney area of Virginia is very similar to Shropshire in the English Midlands on the Welsh border. I'll bet he does not know how true that really is!



What looks like wood chips or soil here is actually rock -- a brownish shale in various states of degradation. Note the careful rolled-over mound at the lip of this groundhog den. Unlike a groundhog, a fox digging a natal den will generally kick soil backwards in a random plume like a dog.
..