Archive for the 'Geology' Category

Fool’s gold

Monday, February 20th, 2012

fool's gold

This post was one of my anachronisms. I wrote it on August 1, 2011, and backdated it. And now I have brought it here.


After we had the road through the trees cut and graveled with limestone, we would often find bits of calcite. Most were tiny pieces but a few were as big as my thumbnail. (It’s a perfectly normal sized thumbnail.) It was always easiest to find by walking uphill, with the sun at our backs. Any little sparkle in the gravel merited investigation, and sometimes it would turn up a calcite crystal, which was nice.

After we had the cabin built and gravel spread on the parking and the fire ring area, we began to find bits of fool’s gold on the ground. The white gravel beside it is usually discolored with brown, presumably a type of rust from the pyrite. Most of it was tiny bits, hardly worth the bother of bending over to pick up. Some of it was just an edge of pyrite on a larger matrix of gravel. The better pieces are being collected on a windowsill in the cabin.

I suppose the gravel that was most recently spread was from a different part of the quarry, yielding less calcite and more pyrite. Life is exciting in that way sometimes.

Over the months I’d supposed I’d found all of the decent-sized fool’s gold to be had by our cabin. On our last visit to Roundrock, however, I turned up the nugget you see above. It is larger than my thumbnail and it’s solid pyrite. I saw only the tip of it emerging from the gravel in the parking area, and I only bent to examine it out of habit. But as I cleared away more gravel, I found that it was larger than I had thought. Once it was liberated, I rinsed it with some water and revealed the big nugget.

It makes the think there are more like it to be found. Now if only it was worth something.

Cast in stone

Monday, November 24th, 2008

I have round rocks by the hundreds at Roundrock, but I don’t pay much attention to the many fossils that are there as well.

This one stood out when I saw it. I’m not sure just what is fossilized here. Coral? Sponge? Some thickly veined leaf? Actually, it looks as though there are two fossils here: the latticed item on the left and the star-shaped item on the right.

This is not a facile fossil to research. I found a few online fossil identification sites, but it seems that you must know what kind of fossil you’re looking for, and then they will display an example of it for you. Good for them but not for me.

If you have any clue, I’d be glad to hear it. Otherwise, simply enjoy.

Missouri calendar:

  • The Missouri Natural Events Calendar is blank for today.

Today in Missouri history:

  • The King of Ragtime, Scott Joplin, was born on this date in 1868. One of his most famous tunes, The Maple Leaf Rag, was named for a nightclub where he performed in Sedalia, Missouri.
  • Positive thinker Dale Carnegie is born in Buffalo, Missouri on this date in 1888.

Round rocks

Monday, July 28th, 2008

round rock.jpg

I have been told that I don’t feature my round rocks enuf on this humble blog. I suppose with the waves and waves of new readers that come by here (/sarcasm) there are always people who don’t know about them and think this blog is about some place in Texas.

Well, unlike that place in Texas, which has only one round rock that doesn’t even look all that round, I have hundreds of round rocks. They come in all sizes, from as small as a golf ball to larger than a bowling ball. Many of them seem perfectly round while others are egg shaped. We’ve found a few that seem to be cojoined and have peculiar shapes, including one Libby calls the platypus skull. Some are smooth while many are pocked and pitted like the surface of the moon. Some have eroded to expose their shale core, which has quickly eroded away, leaving a hollow within the round rock.

My round rocks have an extra-terrestrial origin, too. They are not from outer space, but they were created by a visitor from there. A meteor strike in the area hundreds of millions of years ago in the shallow sea that covered the area at the time created a mineral rich soup in which the round rocks congealed.

I’ve given away a few of my precious round rocks, but it’s felt like giving away my own children. I suppose I could do it again, but maybe not.

Missouri calendar:

  • Wild plums ripen.

Today in Missouri history:

  • Governor Thomas Crittenden offered a $5000 reward for the arrest and conviction of members of the Jesse James gang in 1881.

It’s just not right!

Friday, July 4th, 2008


Little did this poor round rock know over the hundreds of millions of years that it formed and eroded that fate had this ignominious end in mind for it. It’s just not right!

Not only that, but it’s one of a pair that are used as pen holders! I shake my head in shame, knowing I have let the rocks down in the face of an overpowering force that had this in mind for them.

Many round rocks have found their way to suburbia, and I’ve promised them all that I will return them some day. A few have slipped beyond my hands and are making their way in the big world, but do they ever write to let me know how their doing?


To all of my readers from the States, Happy Independence Day! Be safe. Celebrate your freedoms by reading a banned book!

Missouri calendar:

  • Independence Day
  • Earth farthest from sun (aphelion, about 94 million miles).

Today in Missouri history:

  • Groundbreaking ceremonies for the construction of the Pacific Railroad were held in St. Louis in 1851; the line was to go from St. Louis to Jefferson City and then to some point on the western boundary.
  • The Eads Bridge, spanning the Mississippi River, was opened in St. Louis in 1874. Many believed it couldn’t be built, but it still stands today.

Unlucky rock

Friday, June 13th, 2008


I hope you can tell from this photo that the top of this unlucky round rock has been chipped off. An inch-thick layer of rock is missing, revealing another round layer within.

I’ve had a few people leave comments on this humble blog assuring me — nay, insisting — that my round rocks achieved their shape through tumbling in moving water. Odd, then, that a bit of this rock could chip away and reveal an inner roundness.

My round rocks are concretions . They were formed in the slurry of minerals created when a meteor stuck the earth in the shallow saltwater sea that covered part of what we now call Missouri. I first wrote about this more than three years ago in this popular post .

I hardly ever collect the round rocks I find in my woods any more. I already have so many in piles here and there. I may as well leave them where they are than carry them a half mile through the forest. Often when I find an especially nice one, I’m not wearing my backpack, and the thought of carrying it along in my hands is unpleasant.

Sometimes I think I should go on an expedition to find some really good ones to give away to friends. The few I have given away, though, seem like lost children to me, so the thought of giving away more gives me an ache.

Missouri calendar:

  • Yuccas bloom

Today in Missouri history:

  • Daniel Webster visited St. Louis on this date in 1837. He was jaded with his political life, but the enthusiastic support he received on his tour of the west rejuvenated him, and he went on to provide public service for many more years.

Top of the rock

Wednesday, May 14th, 2008

big rock.JPG

Some geologists have claimed that all of Missouri (and some of the surrounding, lesser states) is one giant granite mountain, the summit being Taum Sauk Mountain in the southeastern corner of the state. All of the other landforms in the state are merely deposits that have accumulated on its slopes.

I suppose if Roundrock had a summit, it might be the large rock you see in the photo above. We had found this boulder soon after we had acquired the property, and we visited it frequently in our early years until other discoveries on the land called to us.

On Sunday when we were there, Libby and I wandered over to this spot (it’s near the entrance and not far from the clay deposit that I recently found), and for the first time I considered what type of rock it might be. I was surprised when I realized it is sandstone. I had always assumed it was some variety of limestone. The weathering on it helped mask the true nature of the stone.

From what I can tell, the top layer of stone at Roundrock, just under the soil, is sandstone. This overlays the deposits of round rocks, which are chert nodules created by the meteor strike, which in turn overlays the limestone at the lowest point of our land. In some parts of the county the sandstone is as much as seventy feet thick. I don’t think that is the case in our part of the county though, but I’ve not done any drilling.

Perhaps this boulder is the "summit" of our sandstone layer. We have no other outcropping like it (though we have some slabs that were unearthed and stacked by big machines when a road was cut during the cattle ranch days).

I always imagine a sandstone bed getting laid down under a tranquil sea (and this part of Missouri was underwater millions of years ago), and in that state, I wouldn’t think there would be much that would cause any higher or lower spots in the sediment. Thus a prominence like this seems uncharacteristic.

Some years ago when I was on the meteor tour with the geologist who made the discovery, he showed us some vertical slabs of rock — great chunks of some stone larger than a house — that rose from the forest floor completely contrary to the normal way of things. The impact of the meteor had folded and lifted the stone, and he suspected that there were all sorts of weird formations throughout the county, most of them buried but waiting to be discovered.

Perhaps this is why my bit of sandstone rises above the forest floor too. It’s hard to tell from the photo, but the "graining" of the sandstone is twisted and tortured, so maybe it was subject to powerful forces. It’s worth considering. My tenure at Roundrock has been like my own personal voyage of discovery.

Missouri calendar:

  • Cuckoos (rain crows) return this week to nest.
  • Fawns are born through late June.

Today in Missouri history:

  • The Lewis and Clark Expedition sets out from St. Louis in 1804.

Grab a gob of goo

Wednesday, May 7th, 2008


I grabbed a gob of goo, but not the loathsome goo at the bottom of the pond. This is the clay I told you about several weeks ago that appeared under the gravel in the wet-weather stream where it enters our woods. The heavy rains washed the gravel from atop the white, smooth mineral, and I suspected it was clay.

Just before Seth and I left Roundrock on our last visit, we stopped at the clay deposit, and I wrested some free with the shovel. Then I started working it with my hand. It was malleable, though it wasn’t like modeling clay or putty. It would be hard work to make a teacup out of this stuff. Even so, I could push it around relatively easily with my thumb, as you can see in the photo above.

I had a hard time rinsing it from my hand. I’m not sure what that says about its mineral content, but I know the Bentonite I have thrown in the lake makes the skin of my hands sting if I make too much contact with it. (I can’t believe they feed that stuff to cattle!)

I don’t know how large the deposit is, but it’s worth exploring a little with the shovel. While I don’t have plans to get a kiln, I might try to quarry some and let it dry then pulverize it and throw it on the waterside of the dam. Maybe it will help seal the leaks. I don’t have any plans for exporting it though.

Missouri calendar:

  • Brown bats are in nursery colonies.

Today in Missouri history:

  • “Mr. Missouri,” Dr. Floyd Shoemaker was born on this date in 1886. He wrote six books on Missouri history and edited or co-edited thirty others.

Deep in the valley

Thursday, May 1st, 2008


The Ozarks are among the oldest mountains on the earth They have been eroding for a long time, so what you see now are rolling hills of what were once mighty peaks. (Well, I don’t think they were ever all that mighty, but they certainly are old.)

The Central Valley at Roundrock (on the edge of the Missouri Ozarks) where we carved out our lake bed was filled mostly with gravel. It washed down from the hillsides. Old accounts of Ozark streams and rivers tell of great sandbars. These are no more. They have been replaced by great gravel bars. The extensive timbering of the Ozark pine and oak/hickory forests in the last century allowed the hillsides to erode even faster, filling the streams and rivers with gravel.

Anyway, all of that gravel that had been washing into the Central Valley over the centuries was pushed into making the dam (which may explain why it leaks so much). The bowl was formed and in due time it filled with water. Then it drained away. And filled with water again. And so on.

The natural order of things, of course, calls for the valley to fill with gravel and soil again. You can see above how it is already happening. That is a picture of the road leading to the dam. The gray/white gravel we had brought in to pack down and give us a good base. The brownish orange stripe crossing it is where the rain from the recent toad stranglers has eroded the gravel and exposed the soil beneath it. In some places the erosion is four inches deep.

That soil actually looks like it has a good amount of clay in it, so if it does wash into the lake, it may help plug the leaky dam. I’ll try jamming some larger rocks in the rift and see if it slows down the erosion. Sooner or later we’ll need to get the gravel on the road refreshed, and we’ll correct this problem. But only for a little while.

Missouri calendar:

  • May Day
  • Ring-necked pheasant crowing is at its peak.
  • Jack-in-the-pulpits bloom in the woods.

Wildflowers in bloom in Missouri during the merry month of May:

Yellow star grass ~ Squaw weed ~ Dutchman’s breeches ~ Wild sweet William ~ Blue-eyed grass ~ Missouri primrose ~ Purple coneflower ~ Columbine ~ Spiderwort ~ White trillium ~ Bird’s-foot violet ~ May apple ~ Jack-in-the-pulpit ~ Rue anemone ~ Rose verbena ~ False rue anemone ~ Shooting star ~ Larkspur ~ Yellow lady’s-slipper ~ Bellwort ~ Virginia bluebells ~ Pussytoes ~ Beard-tongue ~ Wild hyacinth ~ Tickseed coreopsis

Today in Missouri history:

  • Martha Jane Cannary-Burke is born in Princeton, Missouri in 1852. She later became known as Calamity Jane.
  • In 1858 John Hockaday begins weekly mail service between Independence, Missouri and Salt Lake City.

What next, a kiln?

Thursday, April 24th, 2008


And of course you’re wondering what this picture is supposed to be showing you. It’s a little surprise Libby and I found when we were at Roundrock recently. You’re looking at a bit of stream bed at just about the very top of the watershed. What I want to show you is what is under the water.

The whitish substance is soft clay. I didn’t reach into the water and try to grab a gob of it, but I did poke at it with a stick, and I was able to bore into it a bit. If you can see a bit of cloudiness in the water, that’s from my little effort.

I don’t suppose I’ll be digging this out and throwing pots with it. (And where do you suppose the word "throwing" came from that people would use it to describe making pots?) I have no creative skills in the real world, and I’ll leave that to those who are far superior than I .

What I would like to see happen, though, is for this softish clay to erode into a fine dust in the water and get carried all the way to the lake a quarter mile away where it could find its way into the leaks and help plug them. I understand Bentonite is a better clay for the job, but I’m not going to look down on any clay that is willing to help.

I don’t suppose I could dig out this clay and carry it to the lake myself with any hope of it doing the work I need. I don’t think lumps of clay would do the job, and without some turbulence to help break it up, I don’t think throwing chunks into the lake will make a difference. Perhaps I could dig out a chunk, let it dry, and then grind off powder from it to dump in the lake. Or I could go to the feed store in town and buy a fifty pound bag of Bentonite and half fifty days worth of powdering effort all at once.

Still, I hope that it is eroding from here and finding its way to the lake. Maybe I should try to expose more of the bed so that more of it can get washed downstream. So many plans!

Missouri calendar:

  • Cedar-apple rust appears.
  • Coyotes bear young through May.

Today in Missouri history:

  • Missouri’s Council of Defense was organized on this date in 1917 to support the war effort. In addition to increasing crop output, it advocated the elimination of the German language in official spoken and written communication and led to the eventual elimination of Missouri’s fifteen German-language newspapers.
  • A bill creating the Missouri State Highway Patrol was signed by Governor Henry S. Caulfield in 1931.

Heart of the Matter – Part 7

Wednesday, March 26th, 2008


I came across this round rock on the side of Libby’s Island (a.k.a Wildflower Island and Barataria) when we were stumbling about one of the dry parts of the lake bed on a recent visit. I’m surprised I’d never seen it before given how much we visit this island and how the rock was just sitting there in an obvious place, waiting to be found.

What especially interests me is the round-rock-within-a-round-rock. I’ve seen quite a few of my round rocks that have been cleft more-or-less cleanly in half, and many show the more-or-less concentric rings of the rock’s “growth” over the more-or-less millions of years in the mineral soup. (The soup was created by the meteor impact in the shallow sea that once covered this part of the earth we now call the great state of Missouri several hundred million years ago, but you know that already. In case you don’t, though, you might want to go here.)

The round rocks all grew around some nucleus stone, but I’ve always thought that the gradations in the growth were mostly continuous, not like rings of a tree that happen in a sequence based on growing seasons. The fact that this rock broke along what seems to be a clear point of transition within the sphere makes me wonder about my conclusion. I really don’t think these rocks were subject to periods of growth and then periods of stasis. That might explain why this rock seems to have the transition point though. Perhaps some dramatic change in the chemistry of the soup one day caused a hiccup in the growth process. (I’m speculating wildly, of course, and you are welcome to jump in and correct me.)

I suspect this poor rock was just going about its business when the bulldozer arrived one day to begin building the lake. I’m guessing that the rock got under the treads of the dozer and got partly crushed, breaking off the outer layer and exposing the inner sphere. Maybe that is why it broke so differently from the other round rocks I find crushed in the lake bed and on the hillsides.

Missouri calendar:

  • Newly emerged zebra swallowtail butterflies fly in woodlands.
  • Gooseberries begin blooming.
  • Swallows return.

Today in Missouri history:

  • On this date in 1804, Congress divided the Louisiana Territory into two areas, one of which became the District of Louisiana with government in St. Louis. Missouri was formed from this.