Geoscience Education in the Mountain State:
CATS Geology Telecourse, Spring 1999,
Show 3 Transcript

CATS Telecourse Broadcast
Historical Geology
February 10, 1999

Dr. Bob: Greetings everyone! We've here for CATS Historical Geology, our third installment. We hope everyone is back and enjoying the early spring that's coming about. We probably shouldn't talk about it that way. Winter will come back and nip us again. We have a couple of things to share in just the bookkeeping because books was one of the problems. Many of the folks have their books but not everyone.

Deb: Twelve people don't have their books yet. They're on their way. As soon as they get to us, we'll get them to you.

Dr. Bob: For some reason the real delay happened in getting the last copies back to us.

Deb: We anticipated 60 people signing up for the telecourse. We were really popular and got 75. That's why we were short on books.

Dr. Bob: Those of the folks here in the studio audience are among those that do not have the books. We will be getting those out to you soon. Deb, would you like to talk about the Web site?. Give us some information.

Deb: We're going to access the Web site live and walk you through it to show you what's there. That way you can know where it is, what to look for, and the benefits of using it. We're at the home page for the West Virginia Geological and Economic Survey. In order to access the telecourse information, you simply scroll down and look over in the first column to where it says "Geoscience Education." Simply click on that and you'll come to Tom Repine's part of the Geological Survey's Web page. It has a little scenario there talking about the goals of the West Virginia Geological and Economic Survey's Education Program. If you click on any one of these highlighted terms, you'll go to a different location that talks a little bit more about that particular aspect. We're interested in the CATS Coordinated Thematic Science or Earth Science Connections Telecourse, so we'll click on that. That brings you to the telecourse section. We have information from the 1997 and 1998 telecourses. You're area is the Spring '99 telecourse section.

The first section you see is news and Saturday information. This is going to talk about the Exploratories which we'll mention a little later.

The next section provides a course overview and a copy of the syllabus, which you all have in your possession by now.

Next you'll find show transcripts.

And quizzes are at the bottom. We'll click on Quiz #1. We put the quizzes on line so that you can actually respond to the questions on the quiz and submit them via e-mail. When you submit these, they will go directly to Tom Repine. You don't have to worry about the paperwork of having to write these manually out and then mail these to us. You can just submit them online. For right now, we only have name and your site location listed here. We have no real way of acknowledging that we've received your quiz if you submit that online. What we would like you to do is, next to the name of the computer, we'd like you to put your e-mail address. In the coming week, we're going to put a little box down there for your e-mail address. So once we receive your quiz, then we'll respond that we've received it. You have a little box to put your answer in. Simply click in that box, type in your answer, and then switch down to the next question. The only problem with the boxes is if you get to the end of the line, it will keep scrolling to the right, and you might get a bit discouraged because you can't read what you wrote. If that happens to you, just hit enter when you get to the end of the line. Then you can see your entire answer within the box. Type directly into the box and when you get to the bottom and you are happy with your answers, you've got two choices: you can either submit or you can clear the quiz. Hopefully you'll be submitting the quiz and you're not unhappy with your answers. If for some reason you are not happy with part of the answer that you gave to number 1, you can certainly go back up and edit that. You're not locked into that until you submit the quiz. You've got a little bit of flexibility until you submit it. If you make a mistake, submit another one and tell Tom which one to us. It seems to be very user-friendly. One of you has tried it and reached us successively, so we're happy with that. That is how you use the quiz and again, you can refer to the transcript.

Something else on this Web site that we'd like you to see--from the home page in the far right-hand corner it says "Mini Museum," and click on that. There are some interesting things that you might be interested in looking at or might be able to use in your classroom. We talk about the Mini Museum at the West Virginia Geological and Economic Survey. There are two sections here that you can go to: one on fossils and one on rocks and minerals. There are lots of really nice shots in the fossil section. For example, the mastodon tooth which was found in Bowden Cave in Randolph County by the curator Ray Garton who's doing this particular part of the Web page. You would see lots of nice color photographs of the fossils, something you might check out since this is Historical Geology.

That pretty much gives you an overview of what's on the Web site.

Dr. Bob: We point out that it may not be showing totally on your screen. It will show on your video when you bring it up on the Web site. The transference onto the television isn't going to bring all the words right now. Don't worry about that. That's not a real problem, just a transmission problem now.

Deb: The fossil page does take some time to load. I have an older computer and I'm using 3.1, so it did take a bit of grinding before all the pictures did show up. Be a little patient with the older machines. They will eventually load.

Dr. Bob: One comment with respect to the quizzes. We will discuss each quiz. We'll urge you to talk to each other, but each person must submit his or her own answer. That's all we ask.

Deb: The other order of business, a little cleaning up, we'll talk a bit about the Exploratories. Remember the Exploratories listed on your syllabus are March 20th, April 24th, and May 1st. Mark those dates on your calendar. We only have proposed locations at this point to give you a general idea of where you'll be reporting. We're working to get St. Marys for a site that's more centrally located between the Parkersburg, Brooke, Hancock, Roane, Wheeling Park, and New Martinsville sites. If that falls through then the site will be at Parkersburg. The second location will either be at the Braxton Middle School or somewhere in Summersville. We'd like to do it in Summersville because that alleviates some of the drive for the people coming from Fayette. Then finally, for the people up north and to the east, we're trying to get a Buckhannon site. That way the Pocahontas, Franklin, and Elkins people as well as Morgantown can get there in a reasonable amount of time. If that falls through we might have to shift towards Elkins. That gives you a general idea of where you'll be reporting for your Saturday Exploratories.

Dr. Bob: We will get information to you. We urge you, when possible, to have a car pool. We will start at a reasonable hour in the morning, 10 o'clock, so that gives you time for an hour, hour and a half amount of travel time. We'll end at 3:00 or 3:30 so that you can get back at a reasonable time. By March, we won't have any bad weather at all, it will all be spectacular. It'll be a great day for a field trip!

Deb: One of the reasons we pushed the Saturday sessions to the end of the semester was to try to ensure some decent weather. That's what we were gearing for. We really didn't want to plan an Exploratory in the middle of January.

The last order of business is to announce that we do have the Fall 1999 course coming to you. That will be an Environmental Geology class and it will be offered on Monday evenings. We're trying to firm up the dates and times for that. The Fall 1999 course in Environmental Geology--it will be run very similar to this one, same format, weekend Exploratories, two hours on air, shared with Biology.

Dr. Bob: We'll be doing some new types of things. We're always out to try some new and additional things, perhaps leaning more and more on the Web site.

Deb: I think that cleans up the paperwork.

Dr. Bob: OK, tell you what! Let's take a few seconds to look at the first four quiz questions. I'm not going to give you answers. For the quiz questions, when I write these quiz questions, there are no fixed answers that I'm after. I'm after good thinking, good sound thinking in geology and therefore you could say some things that aren't appropriate within the context of the scene that I have set. In many cases, drawing a picture of what I have suggested in the question is extremely useful. Sometimes I call them cartoons but the picture means you take the words and you put them into the drawings.

I'm going to talk about question one and in that question, I am asking for a situation where you're out on the highway. There's 25 meters of rock exposed. That's a pretty substantial exposure. What you find are that the rocks are nearly horizontal and there's two types of rocks based on the minerals found. The lower 20 meters are silicate minerals, and I give you some particle size. The upper portion are grains with crystals when they are examined under the microscope and there are carbonate minerals found in that upper portion.

The first thing might be to look at the side of the sketch as you work out your preliminary work. First thing I'm going to do is draw the picture. There's the road cut and the total height is 25 meters. The situation is that the lower 20 meters are grains, and as you look through the text, you find that those are sand-sized grains. The upper is dominated by minerals that are calcite carbonate minerals. We talked about the different rock types and their symbols so that in your analysis, you say sand-sized grains, and the mineral is a bit rounded or subrounded. So they have been worked around. What's the rock type? The rock type is the same as the lithology. If it's sand-sized particles, the stone that results is a sandstone. The carbonate lithology then is a limestone. At the top of the quiz, we have here the resources, chapter two and chapter six. Not because the answer is specifically in that chapter, but because the material in that chapter will help you along with some of the handouts in providing the information.

OK, you have sandstone and the limestone. Which is which? What is the rationale for your answer? Obviously on the Web, you can't draw the picture, but you have a hard copy, you have your notes, and therefore in the hard copy of your notes you have the wording you put together: the rationale for deciding which one was the sandstone, which one was the limestone. I gave you the answer, I wasn't supposed to do that.

Question number two. Quite often the space provided on the quiz generally would be sufficient to hold your answer. The second question is speculation again so that each person's answer could be a bit different. I asked you what would happen if you took a thousand milliliters of normal sea water and it evaporates. What do you think is going to be left? Assume you take all the swimming critters and the floating critters out, and you're just left with sea water. What's going to happen?

Deb: You don't want a quantitative answer here.

Dr. Bob: No. I want qualitative answers. As a matter of fact, we're really going to get into some of that discussion in the second half of tonight's presentation as we talk about sedimentary environments. We're going to talk about the natural environments of the fluids in motion: water, wind, ice. Then we're going to relate that to the characterization of the particles that it carried, transported, and eventually the fluid in motion is no longer in motion and those particles drop out, and therefore they become the deposits. They may be moved again or moved quite often until they are finally buried and taken out of the transport system. In which case, they may be subjected to the cementation process and eventually become lithified into rocks. So we'll talk about that.

The third quiz question, there are substantial limestone deposits in Jefferson and Berkeley counties. In the kit that everyone has, you have received the geologic map of West Virginia. This a general geologic map. It's not going to provide the type of details--if I lived in Charles Town on E Street, could I find out the rock type? The answer is no. But if you're asking about Jefferson and Berkeley counties, I pose the question for these two counties first, and I say that there's limestone. But there's also limestone in Greenbrier and Monroe counties, and then I say just because they are the same rock, does that mean they're the same time period? I'm asking you to speculate. Having read chapters two and six, listening to what we've already talked about before and perhaps more information tonight, you'll come to some speculation if that's the way you want to correlate them simply by rock type, you have to justify that. I always urge you to read all the questions before you start answering them.

Question four and question three--there seems to be some connections. The connections here are in question four in the quiz, I am posing a situation that there are fossils in the limestone. These specifically are invertebrate forms with two shells. They're brachiopods. They're not very abundant in today's oceans. They were very abundant at the time this rock was formed. That rock is exactly the rock I was using when I set up quiz question number four. In quiz question number four, it says that they're from quarries near Lewisburg, Elkins, and Morgantown, and they have brachiopods on them. If you were a brachiopod and you were just have a great old time living on the surface of the sea floor, would you be vulnerable if other forms, vertebrate forms, were developed that had the ability to crack shells? If you didn't live down in the mud, you'd be vulnerable, wouldn't you? There's another two-shelled creature that does have the ability to burrow down in the mud. Those were the pelecypods. Clams are one good example of pelecypods. Guess which one is still very abundant in sea floor environments today? The ones that got out of the way. They can't run away. They couldn't swim away but they could bury themselves and thus be a bit more protected. These are the types of things that we will discuss more.

The question here, the first question for this particular sample, is once you have the fact that the fossils are exactly the same at all three sites and the lithology is all the same, does that allow you to correlate it? I could have gone a step further and I'd say the same brachiopods are found in Greenbrier County in a limestone with any sand grains at all. But in Grant County you find the same fossils, but they're in a limestone with some sand grains in it, 10-percent sand grains. Does that mean that they were all deposited at the same time? If it does, how do you account for the sand grains? That's where we go to in the second half of tonight's presentation.

These are the types of questions that we're asking. To demonstrate that we have the next series of quiz questions, I'm going to just keep numbering these sequentially so you know where you are, rather then saying quiz one, question one. We can always talk about question number six or eight or 10. You have not received this as yet. We'll put it up on the Web site. We are holding it back until everyone has a textbook. We're not going to rush you. What I would hope is that by the time of the next show, which would be March 3rd, when we meet again, I would want everyone to have completed quiz number one. You will probably, for almost two weeks, have had the questions for quiz number two, but that wouldn't be due until a later date. Quiz number one due date is officially March 3rd. The ones who have already sent them in might be saying I didn't get all these hints. Not to worry, we'll let you do it over again if you so desire.

The other thought is you may be lured into the situation where you're doing stream of conscienceness type answers. You're sitting in front of the Web site and just typing away and getting in a great answer and you push the button and you lose everything. You may want a hard copy, but what you may want to do is formulate your answer after you've drawn a sketch. Remember these other questions. Could you draw a cartoon or a diagram for those? The answer is, oh yes, if nothing else, the different locations in the state where the limestones are found.

As you will see later on we can create what are called "fence diagrams." Geologists love to do this. We put on our hats of imagination when we get into the younger grade school classrooms, and the third and fourth graders know exactly what you're talking about. We unfortunately seem to lose that by the time we talk to tenth and twelfth graders and the college students. In your mind's eye, put on your hat of imagination and visualize what it might look like if you drilled down at several points in the state. Then draw an imaginary fence in between and interpret the geology between those two drill holes. Then you do the cross section of geology in between. That's known in geology as a fence diagram. We'll bring along some neat spiffy things that you can do relatively inexpensively to create some of these things in your own classroom for Exploratories--neat little hints that you can carry along.

Deb: Were you going to go over the packet materials?

Dr. Bob: Yes, comment if you will on the packet materials. Everyone should have their packet materials by now. It did not include the second quiz, but that will be forthcoming. One thing that was in there was the geologic map. Deb, geologists just love the geologic column. This is for West Virginia and we've retyped it and printed it for you. What do I have to know about this? What do I have to memorize? I would urge each and everyone of you to memorize these terms that are called periods of the Paleozoic. The Paleozoic is a term derived from "old paleo life" zoic. The periods of the Paleozoic are what I would expect that you should want to commit to memory in order. And by tradition, from the bottom to the top, oldest to youngest, because of the laws of superposition. That's the way they happened in time. On all the geologic columns, we build it from the bottom up. You'll see that in some places we put a squiggly wiggly line. That wiggly line very clearly defines erosion. A tremendous amount of the record of Earth's history has been lost. The possibility also exists that in this state of West Virginia, the rock record of deposition was not continuous. A combination of a lack of deposition and erosion has created a break in the rock record. Those are important things.

When we get to the other terminology, and especially when we meet out in the field, we may come to very clear distinctions and use these terms. For example, the Helderberg Group. I will use the term Helderberg Limestone quite often. When I refer to that, it not only refers to a certain time, because which period of the Paleozoic is the Helderberg? It's in the Devonian. Also, it's lower Devonian or in a time frame, early Devonian. It's lower because it was deposited early. It's down near the bottom. The rock is in the lower Devonian. The time for the deposition of that material, not as rock but as carbonate mud, was early Devonian. That's how we use those types of charts and diagrams.

There's a second one here, far more complex. It shows a lot of additional information that you do not need to commit to memory but you can see that the characterization--a good cartoon with a oil well. Where are we going to find materials? It just shows as if there is a well extending all the way down into the basement. We do drill from time to time. Some of you will recognize that there is a derrick for oil or natural gas. We don't get oil or natural gas out of the Precambrian basement. One interesting thing, and a neat Exploratory, is if you had a big refrigerator cardboard carton, you could make an elevator at your school to get down to the basement. What you can do is create a scroll of the rocks that you might expect on the way down. Kids get in there and then you shake it a little bit. They have a marvelous one of these set up at the Carnegie Museum. You have to watch the shaking--it can evolve and degenerate into a tipping over the box type thing. In a more elegant situation, they actually have you shaking and moving down and then seeing on the screen the rocks that you would pass on the way down.

Deb: Couple of things. There's a typo in the center of that handout, in the Devonian Oriskany sandstone. We just retyped this so sandstone shouldn't have two s's in the center of it. Eliminate that.

For those of you who are daunted by memorization, there's a simple pneumonic that you can use to remember the order of the periods in the Pennsylvanian. That is simply by remembering this sentence. The first letter corresponds to the names of the periods: Campbells for Cambrian. Onion for Ordovician. Soup for Silurian. Delights for Devonian. Many for Mississippian. Poor for Pennsylvanian. People for Permian. So that's the classic pneumonic that most geology students use to remember that. Once you've got the names of the periods down, we use them so frequently that that's not going to be a memorization problem. All you're going to have to do is you hear them. You hear them and you'll remember them. Just putting them in order, it's just remembering that sentence. It's not something that's going to be difficult. You can really learn this very quickly.

The derrick for the geologic timetable has an enormous amount of information on it but it's really nice because it collapses a lot of what we're going to be looking at here during the semester and the in Exploratories onto one sheet of paper. Usually you have to go back and forth between the geologic time scale, and then you have to go to your notes to figure out what was happening and what rocks you were looking at. This really collapses everything nicely. You're looking at what types of rocks generally occur during that time. You also see the years. When was this rock formed? You've got that right here. It really is a nice synopsis. Don't be afraid to use it.

Dr. Bob: Not years ago specifically, but years duration for the period. We will talk about that because the actual times, the absolute times, are constantly revised and revisited by geologists around the world. I'd also point out that on the far right column on this some of it is pretty hard to read. Through the years as this has been copies of copies, this had not been done in quite a while so do the best you can. We'll see if we can get a little expansion of that sometime, but a lot of that writing has been lost in time.

Additionally in the package is a brochure from the Black Hills Institute, "What is an Ammonite?" We'll talk about this as we talk about the fossils specifically. A real good question is: What is an ammonite? Why isn't the chambered nautilus an ammonite? It looks a lot like it. It's coiled like that. The living form is sticking out over here. The living chambered nautilus is about as big as an eight-and-a-half by 11 sheet of paper. There's some good-sized ones. You usually see it sliced in half. This doesn't help the chambered nautilus population. They've become real popular. When you do slice it in half, it will immediately help you identify why the chambered nautilus is not an ammonite. All the ammonites became extinct at the end of the Mesozoic. The reason it's not an ammonite is that the separations, the critter, this invertebrate form, lives in the outermost part of the chamber. Everything else is filled with gas which helps make it float. The critter can adjust the gas pressure because they have a tube, a lot like a straw, that goes back into all the chambers and they can adjust the pressure and they can float. They can move around. It's not like swimming per se, but it's a type of locomotion at least. The individual parts of the shell that separate the living chamber, as the animal gets bigger, it abandons its former chamber and builds a new one. That part of the shell is just perfectly smooth. It's curved but it's perfectly smoothed. That's why it isn't an ammonite. Ammonites had an incredibly complex separation material. They're called septa. They're also in a sense of the chambers extremely complex and that's what made the difference between the simple, more basic type that the chambered nautilus belongs to, and the more complex one like the ammonites.

We have additional ones such as "What is a Trilobite?" There's a good thick packet of many pages and this includes some articles that are the sketches and the drawings that do not copy real well. It does give you a reference. A number of these come from a now extinct publication, Earth, which was just marvelous. In your libraries you may find some of the old copies of Earth. Excellent graphics and colored pictures, etcetera. We have assembled a bit of information for you of articles, references, potential books. A book that I recommend very highly is the Fossil Factory. It is a nice book for younger folks but it really helps describe fossils, how to collect them, and everything from invertebrates to dinosaurs. These are the types of things that we're sharing with you.

We have covered a lot of the basic material. We are now ready to enter into the discussion of sedimentary environments and fossils. First of all, it is quite likely that every single person immediately would recognize the type of fossil. This of course is a fish. It's a vertebrate and it has been encased or entombed in a rock. This particular rock is something all over the United States, if they like fossils, may have bought for a couple bucks. It comes from Wyoming. It was a large, large body of water, a fresh water environment from very early in the Cenozoic. We do not have rocks of that age exposed in West Virginia. Geologists have gone all over the continents, indeed all over the world, and put together the entire history of what was going on by the fragments of the geologic record. Here you get a fragment of this part and over here a hundred miles away you have a fragment there. If you juxtaposed them, you'd see that there's some overlap. You extrapolate in between what has occurred. You sometimes say the environments must have changed. What we have here is a sediment that reflects a sedimentary environment, and the fossil that's in it tells us something about the environment. This was not a flying fish. This is not something that was on land, most likely. This was in a body of water. Did the fish die a natural death or was it destroyed through volcanic ash? We must look at the nature of the rock.

It turns out that if we put some weak hydrochloric acid on this rock, it fizzes. I won't do it on the fossil but I'll turn it over and put the weak hydrochloric acid, 10 percent, on it. Maybe that will tell us something. Does it fizz? Yeah. You can see that there's lots of bubbles. That fizz tells me, then, that the chemical identifies a mineral for us. That particular mineral is calcite.

Deb: Would vinegar have worked for elementary kids? Is that a strong enough acid to create a reaction?

Dr. Bob: It would not be as violent a reaction. For really young kids, I would use vinegar. You should be able to get some of the reaction, yes. Vinegar is acetic acid. It's not quite a strong as this weak hydrochloric acid but the great advantage of using the vinegar is that it smells bad. The hydrochloric acid when diluted like this has no smell at all.

Deb: Actually, for the high school students, I diluted it even more. We used five percent hydrochloric acid. You can even dilute it even more than Dr. Bob did.

Dr. Bob: It will still give a good fizz to it. One of the other types of acids that you can use is muriatic acid. It's the acid that's used to clean bricks and cement. That would serve the same purpose.

The preservation on this fossil has been spectacular. The bony parts are clearly shown. You cannot see the stomach, the gut, the esophagus, all the lungs, everything else in the fish. Hard parts and the appearance of hard parts in the geologic record are the great change in our ability to have a geologic record. Prior to that, it would take truly extraordinary events to preserve the soft body parts. Still, today when we do get soft body parts, an article late December, early January, talked about the best preserved dinosaur ever found with respect to soft body parts, and it is a remarkable find. Most cases we just don't get the type of preservation to maintain a large vertebrate's soft body parts. They have to have stumbled or fallen into something that is truly extraordinary like a peat bog or a tarpit, the peat bogs of Florida or in Ohio, or elsewhere in glaciated country, in the far Arctic north. The La Brea Tarpits in California, right along Wiltshire Boulevard. The buses are moving back and forth and you're looking at animal remains that reflect over a million years of accumulation. It's really a bizarre sort of situation. Occasionally, in volcanic ash falls, we might also get the type of preservation that allows for that.

We got to this discussion from the standpoint that the rock tells us something and the fossil tells us something. We are looking then for a interpretation of sedimentary environments. I'm going to locate a diagram from a laboratory book. This is just a composite. It's the type of thing that you can find in your textbook when you receive one. Not exactly the same one. What it attempts to portray is the three-dimensional diagram of differing types of environments. For example, there are continental environments and oceanic environments. Continental environments can be further subdivided as to whether there were glaciers or whether there were lakes--the fancy word is lacustrine--or whether there were deposits of wind--eolian is the fancy word. It's our jargon word in geology. Fluvial, the rivers. This is a type of game, especially when we talk about connections where you start out with the third and fourth graders and, say, talk about different environments and erosion features. The wind erodes. The lakes would erode when waves go against the shore. On one hand you'd say lakes might be more depositional, but there is still the component of erosion when wind drives the water against the shore and the particles move around. This type of diagram then sets the stage for a discussion of sedimentary environments. Over on this side, we find a swamp. Some swamps, as in West Virginia, our swamps are at high elevation and always fresh water. Other swamps are down along the coast. When you get to the coast, it may be shallow offshore, organic reefs. It may be high energy along a beach. It may be gravity flow down into deeper water. It may be very, very deep marine with low energy but very deep colder water.

So having introduced this, it is time for our break. We will be back in 10 minutes. Talk among yourselves during this time period with regard to quiz number one. If you have any questions, I always encourage you to talk on those quiz questions.

(BREAK)

Dr. Bob: Greetings! Back again. I hope you had an opportunity to chat a bit. Ask questions using the audio bridge if you have a question during the lecture. Call in. Tom will relay the question to us. We had one here in the studio. Angela what was your question?

Angela: When Deb had the Geological Survey's Web page up, she mentioned there were mastodon remains in West Virginia. I thought our rocks were too old to have those remains.

Dr. Bob: Excellent question! The mastodon is Pleistocene. Pleistocene is a time in geologic history that is very, very recent. Pleistocene may go back two-million years. But geologically speaking, that's very, very young. We do have some material of that age. Not rocks, but sediments or materials. The key to this was that the tooth, as well as some other Pleistocene remains of giant ground sloths, other animals that are extinct, as is the mastodon, were salvaged from or found in caves. Here's the surface and here's the mastodon. If it dies and the terrain is underlain by carbonates, there are in places, conduits, down to underground caves, so that rivers carrying bones can flush them down into the cave. There are a number of caves in West Virginia where the limestones are geologically much older. Bowden is almost world renowned. In some caves, there's actually an opening to the surface and some of the critters could have utilized the caves as a shelter. In the case here in West Virginia, the mastodon bones were flushed down in and we find the tooth.

There is another location in West Virginia where we also found mastodon remains. This is one environment, the cave. The other one is the Ohio River. To the north, during the glacial epochs, there was ice. The ice got as close as maybe 15 miles to West Virginia. The Ohio River loops around. The ice didn't quite get to the Ohio River. When the ice melted, sand and gravels and finer grained sediments were flushed down the drainage system. So some of the mastodons walking along the river, going down to get a drink, some of their remains are captured. Not perfect, intact skeletons with all the bones, but the occasional bone and tooth. The exact site in West Virginia is at Boaz.

Which of the two cases do you think is the best chance to preserve the remains of the Pleistocene critters: flushed into caves or buried in the sands and gravels? There's a hint to this. If they are buried into the caves and dropped into the caves, what type of environment is going on down here? Any water that's in the cave has already lost its acidity, hasn't it? It's dissolved as it comes through the limestone. So this is a different situation, but here's the river and then along the banks of the river there's a terrace. Our friend the mastodon was walking along, but if the remains, a tooth, are in the sands and gravels, what is that rain potentially going to do in that sand and to the bones preserved in that sand? It's going to leach through and it is quite possible that after 8,000, 10,000, 15,000 years, some of the remains are dissolved and gone. That's why in the sands and gravels in that region along the Ohio River, there really aren't too many in way of mastodon remains.

On the other hand, if I said let's go up to north-central Ohio, or Wisconsin, Michigan, Minnesota, New York, then I would say let's go looking in swamps. Let's go looking in some of these areas where there was the potential for very rapid burial. In these cases, especially in swamps, there is the potential for preservation. This is a very interesting one, those of you out there who like archeology. There have been found in some of the swamps in north-central Ohio remnants of butchered, crudely butchered, Pleistocene vertebrate beasts like the mastodon. Our interpretation is that the butchering is so crude, it looks like it was done with stone implements--that early man in those areas must have butchered the animals and realized that if they put them into the swamp they would preserve the meat. You might say for some people that might be a preservation where I can come back and eat it later, but not for me. They didn't have salt, they didn't have refrigerators. They didn't have any other way. When you kill a mastodon, you've got a couple weeks--you've overstocked yourself with a meat supply or found a dead mastodon. I know they show some of the early men going after the mastodon with spears and that sort of thing. That's a contest very much in favor of the mastodon. These types of interesting finds occasionally come about.

When we left at the end of the first half of tonight, we were talking about sedimentary environments. Deb had a good question. Let me bring that one back up again and talk again about the types of environments and the fact that when I talk about eolian deposits, sand dunes, that was on land. However, the sand dunes are quite often at the margin between lakes and land, and clearly between the ocean and the land. The reason is the wave action in the ocean pounds the rock, breaks it down into smaller particles. Those smaller particles are then of a size that strong winds or prevailing winds can break up those grains and move them inland. If you've been down to the Outer Banks in North Carolina or many other places--sand dunes along the coastline are an expectation. But, they're very delicate. They're not going to last long. If sea level rises they are at great risk. Those sand grains are temporarily parked until another energy environment comes along, unless the particles get buried and then cemented and made into a rock.

If you're making a list, let's use the common terms. Sand dunes or wind is the active fluid in motion. Lakes, glaciers, streams, and a swamp. Further there is the potential for actually preserving history and fossil forms if a landslide occurs or if a volcano erupts and volcanic ash. Now it's true that the volcanic ash also can work by burying things in water, in lakes, in oceans possibly. The volcanic ash of the volcanoes near the ocean it's quite clear it's going to preserve things. The possibility of finding it in an active zone along a continental margin in the historic record is really rare because you may have to go through thousands and thousands and thousands feet of basalt and ash before you actually find it, find the fossil record. Whereas, a continental volcanic eruption may have distributed ash a hundred miles away and it's only a couple inches thick. [Learn more about on volcanoes in West Virginia by reading the article, "Volcanic Ash in West Virginia," on this Web site.] We have spectacular fossil finds. They were building a bank in Tennessee a few years ago they came across a herd of four or five wild boars, peccary-type critters of Pleistocene age that must have sought shelter with each other in a wind storm. They were buried, suffocated, and the fossil preservation was magnificent. The soft bodied parts were gone but still the fossil preservation was magnificent. There are other cases of volcanic events in Colorado. The Flourescaunt Fossil Beds in Colorado are a series of lakes. It's interesting because the lakes kept forming because the lava flow from the volcano kept damming up the rivers. Then when the volcano exploded more violently, the ash from the volcano buried everything that was alive in the lake at the current time, or at least a lot of the material. Then the sequence is just really spectacular.

This is a good question to ask: how did all the fish get into the lakes in Wisconsin? Deb, have you ever thought of it? You've spent time in Wisconsin. I'm using Wisconsin, it could have been Minnesota too. Not Ohio, there's not that many glacial lakes in Ohio. But New York. Not many in Pennsylvania either but natural lakes. The fish are everywhere. How do they get there?

Deb: Yeah. Some of them we know how. A lot of the exotics got in with man's help. But the older stocking is a really good question.

Dr. Bob: OK. How many of you have ever seen an osprey or a hawk in action? What do they do? They dive, they capture the fish and they usually transport them back to the nest, right? Some of these fish do get away. If you've ever seen restocking of some lakes, they just dump them out of helicopters these days in some areas where the lakes are abundant. Their little torpedo-shaped bodies allow them to survive. When you think about it, a lot of birds in those areas are going to be catching a lot of fish and they're going to be losing some taking them back to the nest. That is a realistic response explaining fish in all these different lakes that are and have never been connected. It wasn't that water covered the whole surface and then the water somehow drained off and left little puddles and the fish were captured. The best answer is those birds losing their prey. These environments, then, that we talked about in the continental areas are landslides, volcanic eruptions, lava flows, and ash. I'd love to take you rafting down the Columbia River, maybe not rafting but we'd take canoes or boats. Then we'd stop from time to time because along the walls of the Columbia, if we climb up the hillside, we'll find horizons of old stumps of trees' growing positions. They are all charred and burned off where lava flowed.

You can see the same type of thing in Yellowstone National Park, but there it is a national park and many more permits have to be acquired in order to go clamoring up the walls of the valley. By the way, it's yellow-colored stone in Yellowstone because it's rhyolite. It weathers yellow because the iron stains it. The basalt does not have as much silica in it. It has a lot of iron and magnesium minerals as silicate minerals and it's black or brown in color. You don't find quartz grains in it because there was insufficient quartz in the magma. The magma comes out and you get those beautiful layers with the burnt forests in between. It's really quite spectacular. It gives you a good impression of recreating the history of the area.

Deb: You mentioned the word "horizons." What does this term "horizon" mean?

Dr. Bob: Horizons usually are referred to in soils. You get the different types. You have a soil color at the top. Color helps differentiate the soil horizons. In geology, also, remember in one of the earlier shows, if you have a room where the bricks, the concrete bricks, may be faced off and they're well painted, but those could be called different horizons in the rock record. If you look at a limestone or sandstone in a quarry or a road cut, you will see that there are very distinct breaks in the appearance of the rock. We call it bedding. The individual beds are horizons. It may not have existed long enough to have soil formed or there may have been a thin soil that got flushed away when the new sediments came in. More then likely, it was a situation where there was insufficient time to create a very distinctive layer to differentiate. One of the great examples is in the tidal zone. The tides come in and out and they do so twice a day. When the tide comes back in, the previous surface has been exposed in the intertidal or between the tides, high tide and low tide zones. So there has been a little bit of alteration but not enough to really change things. The rise in sea level again by the tides--I'm not talking about the big picture of change but the tidal change--will bring in more sediment. What can happen in an environment like that is that in a very dry--when the tide goes, what might happen to the mud? It might dry out. When it dries it shrinks. When it shrinks it cracks. Geologists, not being real inventive in their terminology, quite often call them mud cracks. But when the tide came up again, then the mud cracks were covered with another thin veneer of the mud. The carbonate mud or the silicate mud, whichever, or a combination filled in the cracks. Then the tide went out, the crack formed again, and what happens is that's there is a memory, if you will, in the sediments. The cracks keep forming in the same place. When they open up and they're cracks, when the mud's come back in, guess where some of the mud goes? In between the cracks and it fills it in. That's why it has a memory because it's a different environment.

Besides, how do cracks form? One of my great fun questions is which way is up? If you came across a mud crack, look at it this time. You can do this out on the playground, or in the parking lot at your school. Go out and find an area where it has rained. Maybe a bird has walked across it or a worm has slithered on through. Or perhaps the water was just deep enough that there was enough local relief that water was coming off the parking lot bringing little grains of sand and built a little delta into it. You may even still see the lake. But when it evaporates and dries, you will find the mud cracks. Then you say to the youngsters which way is up? Well, obvious. If it's in the rock record when the clay-rich material dries, it cups doesn't it? In the rock record, if you find the cup in this form, which way is up? That way. But if you find the cups stacked like this, which way is up? It's that way, so the rocks must have been flopped over. What I love to do is take folks to a site not too far out of Moorefield and the cups are like this. They're on their side! Now which way is up? Well, I know because I looked at the present environment and every time I looked, I see mud cracks cupped like this. Therefore, if I find this exposure outside of Moorefield, up must be in that direction. Occasionally in your own classroom area or out in the playground, you may be really lucky and you find mud cracks with rain drop impressions, little bullet-size imprints, and that helps tell you which way is up too, because you know which way the rain came. In West Virginia, we don't find too many of the cases where everything's totally flopped over. We find lots of cases where it's vertical or near vertical or just slightly overturned. That is what happened in the Ridge and Valley physiographic area. The Ridge and Valley is due to plate tectonics. What was originally a sedimentary layer was folded. If the fold is really extreme, you can see that there is a overturn. What used to be up is now tipped over beyond vertical.

I have here in my hand a rock. Let's look at that. I'm not going to do every type of rock there is. Let's zoom in and try to get some focus here on that. You can see some things glistening. You've got some false color but you see some white things that glisten and it doesn't really show that those little things are shiny. What I'm going to do is just simply take another little piece of the rock and rub it against each other. What do I get? I get a whole pile of little grains. As a matter of fact, in some of these you can see things glisten a little bit. These are individual grains. Are they different types of grains? Yeah. How many different types? It looks like at least three. There's one that kind of looks orangish a little bit. There's stuff that's black and there's the shiny white stuff. This is something the vast majority of everyone of you out there, no matter where you are in West Virginia, you can get this type of stone. What would the kids call this, of any age, especially really youngsters, third grade, second grade? They would call that sand. Then you say exactly, and build on it. This must have been a sedimentary environment--the individual grains. What about the rock? Is it toughly cemented? Is it a real tough old sandstone? The answer is no, absolutely not. But I'll tell you this: if Paula and others in Franklin climbed up North Fork Mountain and got a piece of sandstone down, it would be the same sandstone that you would find at Seneca Rocks. If they rubbed one piece against the other, they would be there for quite some time before they got even one grain. If they looked at their one grain under 50x or 100x magnification, even 10 or 25, they would see that they didn't break out an individual grain as we have here. They broke off a fragment of the rock. It broke across the grains because their sandstone on North Fork Mountain is just as tough as can be. The chemical composition is silicon and oxygen--the mineral quartz. The cementing agent is also quartz. In this particular rock, the cementing agent used to be, probably, a limestone or calcite mineral. Now the only cementing agent that remains is the cementing agent that gives this orange color--iron oxides. It's very weak at that.

What if in a future quiz I were to say: list three different environments, the ones we just talked about on the continent in which you could get sand as a broad term? Sand has a variety of particle sizes. The lower grain size and the upper grain size is important to understand, two millimeters in diameter for the upper grain size, one-sixteenth millimeter diameter for the lower grain size. We did a little exercise. We'll probably try to remember to bring that along for those who didn't see it last semester, that when you see particles that are a sixteenth millimeter diameter and particles that are two millimeters diameter, there is quite a difference. Think about it--intuitively it should be clear. Which one particle size, now, of sand is very easy to be moved by wind blowing at a good fresh clip coming off the ocean onto land? The smaller ones. These are the ones that are going to move in a windstorm. But if a hurricane hits, whoa, all bets are off, right? What about a river tumbling down off of Cheat Mountain here in Morgantown? What grains are going to be moved along, maybe bouncing and rolling until they hit Cheat Lake, a stoppage of the flow. If you look at the Cheat River down in Parsons, what grains are going to be moved along? Perhaps all of them. Perhaps even particles bigger than sand size, the silt and clay size. How many of you after some of these rains that we've had over the past two weeks have gone out to look at the creek, and what did it look like? Was it clear or was it muddy? The rivers are carrying a load. They've eroded it from someplace, they're transporting it as you stand there and watch. Those sediments are going to be deposited someplace. Will some of those grains at Parsons get all the way down into the Gulf of Mexico? You'd say, not anytime soon because there are locks and dams all the way down, and you hit the first one before the Cheat even empties into the Monongahela. Then the Monongahela into the Ohio. Then there's locks and dams all the way down. But prior to the creation of those systems, the potential existed for one little grain to go through that odyssey. Maybe it had a temporary storage in the river sediments to be picked up again in the next flood a hundred years later and moved again so that the sedimentary environments help give us a record.

One of the really great sedimentary environments is the ocean. You have this in one of your packages, and what we are going to talk about here is land, the back reef or lagoon area, the reef, and the open sea. Now where would we go on a field trip? You should have a real good feeling to immediately answer that question for the youngster. Where would you go to see a nice reef? Cheat Lake? Deb wants to head off to Australia. In the continental 48 states, I think a number of youngsters might suggest Florida. In Florida, the waters warm enough. There's a very narrow range for the critters that live in that environment. Furthermore, when we refer to this figure, remember that we introduced for you rock patterns. Moments ago we talked about horizons. Each one of these are a bit of a horizon. They're in interfingering. Why has this apparently built up in the direction of the arrow, because that's what looks like is happening, right? Sediments are coming in off the land and they're sand-size grains. Then there's some stuff in here and the pattern here looks like a lot of calcite or maybe silt and mud along with the calcite. This was all darkened in but this turns out to be a great deal of calcite, too. This calcite keeps building up. What would youngsters probably put as the word in front of reef? They probably call it a coral reef. Yet the great bulk of the rock that is being formed is being formed by algae. Corals are real obvious; algae isn't. Algae is microscopic or you would certainly need a hand lens to start seeing the life forms. So really a great deal of the bulk of this is algal growth. It is true that all--many other invertebrates will have external shells and they contribute to the mass. Then what happens from time to time is that wind in the form especially of hurricanes, if this reef is growing in a hurricane area, wind is going to come and destroy and break off particles. So some of these particles get washed over. What is the difference between a lagoon and the open ocean or the open sea? Is there a difference in chemistry? Generally, yeah. Which one would have, if you took a thousand liters of water out of the lagoon and a thousand liters of water out of the open sea, which one might produce when the total liquid was evaporated, which one might produce a greater amount of material? The ocean. Now, a trick question. What if this was very turbid when you collected it in the lagoon? Then you'd have to say if it was dirty water and not clear water, then there was the possibility that fine-grained particles like clay-sized particles were suspended because it was agitated, and therefore I am going to make sure that I collect clear water to the best of my ability and compare and contrast these two sediments.

Deb: One question. If it's in this back lagoon area and the water is evaporating, why wouldn't it be saltier than the open ocean?

Dr. Bob: In some cases, that is indeed what happens. But along the east coast, there's a modest amount of evaporation. If we went to a lagoon along the coast of the Carolinas, we would not have the reef of carbonates. In that case, there's a tremendous amount of water coming off from rivers and fresh water and making it less saline. So what you have to do is say where are you talking about. What was the overall environment?

The final comment on this: what allows for this to keep growing up? Why does this lagoon have sediments of each other--clearly the youngest is at the top--why does it keep growing up and getting thicker? What are the two really simple answers to this?

Deb: One is it wants to maintain a certain level.

Dr. Bob: OK, sea level goes up. You know which one is number two in this list, or an alternate interpretation? As that material accumulates on the continental shelf, what could happen? The shelf could sink. If the shelf sinks at a slow but steady rate, guess what can keep pace? The growth of the reef. The interesting example, if we choose another example, and I take you now on the way to Australia and we stop off in one of the atolls in the Pacific Ocean, this is what we find, going to the overhead. We find the water level here, the water level here, water level there, and rather then a continental form, we find the reefs there, and what do we call this? A lagoon. The reef may be continuous like a donut or fragmented like sections of a donut. These have special terms. Out in the Pacific, you find them very often an atoll. When Darwin looked at this, remember that was the 1840s, 1830s--you know what I think this is? I think that if you dug down, you would find volcanic rock underneath there. Then because this was in warm water, the reef material started growing along the margin of the volcano, and then in the atoll in the center in the lagoon you get this type of structure. He had no drilling apparatus; he imagined that. We almost a century later confirmed that in almost every case.

So, the next situation is--and we show a diagram like this. What did you put together in this, very simply?

Deb: I was trying to simply look at a very basic sediment, series of sedimentary environments, showing that one depositional environment changed and replaced the rock below it.

Dr. Bob: This could be in some place in West Virginia. What do we have down here?

Deb: That's the basement.

Dr. Bob: The basement. On our geologic column, we're going to start talking about this next week. What is the age?

Deb: That would be the Precambrian.

Dr. Bob: OK, it's Precambrian. "Pre" as the prefix means before. That's why prefix starts with pre. Pre before Cambrian. On a map in West Virginia, by convention in many places around the world, you'd find a lower case "p" and a upper case "c," but that "c" has a little dash through it. Why? Because there's lots of words in the geologic time scale that start with the letter "c." Therefore, we have to designate it separately. So that's how we do it for Cambrian. What we're going to talk about next week is the Precambrian basement.

Then we have sedimentary units. In relative dating, which came first? The one on the bottom. Now, notice that there's a wavy line here. What does that mean to you?

Deb: Generally, the same thing that we saw on the geologic column when we were looking at that. That means that some of the rock is missing.

Dr. Bob: Oh, so if we were going to interpret the history, we'd use the word erosion, an erosion interval. There was a long period of erosion. As a matter of fact, in West Virginia, that erosion may have been over 500-million years. Certainly hundreds of millions of years because the age of the rock by radiometric age dating shows it was metamorphosed about a billion years ago. The stuff plunked down on top is Cambrian in age, so that you might find Cambrian, Ordovician, Silurian, and so forth in the younger and younger rock. So what we have reintroduced is a geologic time scale and relative dating.

Then, what if we found someplace in West Virginia where these sedimentary rocks had a dark igneous dike in them. Which came first? Can you interpret the history of something very simple like this?

Tune in next time on March 3rd and we will talk about the Precambrian. We'll talk a little bit at the beginning about evolution and the fossil record to lead into the Paleozoic, but we will also talk about the Precambrian. So in your reading assignments, everyone should have a book within a week. We'll see you. Keep looking at all those good exposures. Don't let any snow in your area cover them up. Have a nice springtime. I'll see you March 3rd. Take care!

WVGES Education Specialist, Tom Repine (repine@wvgs.wvnet.edu)

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