Geoscience Education in the Mountain State:
CATS Geology Telecourse, Spring 1999,
Show 1 Transcript

CATS Telecourse Broadcast
Historical Geology
January 13, 1999

Due to technical difficulties, the earlier portion of the broadcast was not recorded. This transcript joins the program in progress.

Dr. Bob: First of all, we'll just go through some of the basics. Deb, as we finished up in physical geology and our look at West Virginia, what were we talking about in general with respect to the mountains, the rocks, and such?

Deb: In West Virginia, we pretty much tried to tie in all of the aspects of physical geology in terms of what rocks we have here and what has been done to the eastern part of our state by mountain building and plate tectonics.

Dr. Bob: You know, we're all students in this because we all continually learn. Just as a teaser or a hook for the semester, what have we here on the overhead? Well, it turns out that this particular fossil is a tooth. It's a tooth of a albertosaurus. Albertosaurus is a little bit earlier than tyrannosaurus rex. It is a meat-eater. It has that serrated tooth. It can rip and tear and cut and therefore it represents a tooth of a carnivore. So do we have any fossils like this in West Virginia? The answer is, the rocks we have in West Virginia are older then the rocks in which dinosaur fossils are found. Therefore, realistically would you expect to find dinosaur bones in the rocks in West Virginia? No, because our rocks are older than the dinosaurs, they were not yet around. Well, what happened to the younger rocks that may have existed in West Virginia? Where have all those rocks gone, if they even existed at a point in time?

So we have to develop that concept and decide whether, A) the rocks never formed at all; or B) they did form but they're gone. And then the corollary to B is if they're gone, why are they gone? What occurred? What happened in order for the rock material that potentially carried dinosaur bones to be carried away or lost in West Virginia? And, where did they go? And where might that debris be found?

And another situation, the sand and gravels in the Ohio River, they're much younger, but could we find dinosaur teeth there? Don't know. But a big tooth is brought in, a really big tooth. And it's identified as being a mastodon tooth, along with a big mastodon tusk. So, those deposits contain vertebrate forms, teeth and tusks, from a much, much younger critter. The dinosaurs lived most recently until extinction about 65-million years before present. The mastodon were around in North America as recently as 9,000 years off some islands, both off the islands of California and also some islands in the Hoover Bay area off Vancouver and northwest Washington. There were some areas where some pygmy mastodons and mammoths still existed. But otherwise the megafauna, the very big stuff, was wiped out in North America--the mastodons, the giant sloths, and all those other types of forms.

Now to continue this introduction, someone over in the eastern panhandle is expanding their home and digging and they come into an area where the rocks have disappeared and there's a hole in the ground. The locals call it a sinkhole because it is a solution weathering of the type of rock out here, right along Interstate 81. And lo and behold they start hauling out of there teeth and bones and all kinds of things from big critters. Those bones are a lot bigger then any critters roaming around today. Another individual might be caving down in Greenbrier County and they get into a cave and they too find thin layers of mud with lots of bones. The mud is clay, probably brought in by floods. It buried those bones. They're not opossum, not raccoon, they're not fox, or bear or wolf or any of those types of animals. But these animals lived and either fell into these sinkholes, or they may have lived in there. Or, which is far more likely, they died on the surface, rainfall and running water picked up the bones, and flushed them into the sinkhole. And then the bones were buried in the clays that were also brought down in the sinkhole and thus preserved. So we do have some very interesting megafauna or vertebrate remains here in West Virginia, but for the most part we find that we're going to be looking at critters more like seashells. Now the interesting point is that you can get shells that look like seashells that could have formed also in fresh-water lakes. But nobody uses the term "lakeshells." But these [on the overhead] happen indeed to be seashells. They're an interesting type and form because this critter lived only in the ocean. Its relatives, and there are a few today, are only marine critters. Since they only live in marine environments, finding them means the area must have been under the sea.

Now, they all look similar size, don't they? And there's quite a few of them all crowded together. And all of the shells have this same geometry in the same position. There doesn't seem to be a jumble or chaotic burial but rather these were in life position and mud came in a buried them. Therefore, they're preserved and this was the sea floor. So we will be interpreting rock history and interpreting the environments in which the critters formed.

Moments ago I said that we could find bones in the bottom of a cave in West Virginia, and in that environment--the cave is an environment, but the running water is also to be interpreted at being the environment that carried the bones and dumped them in. So this is where we start this semester. This particular course is CATS Geology. That stands for Coordinated and Thematic Science. And how long have we been using it in the classroom?

Deb: It started four years ago. We've been implementing it slowly starting out in the fifth, sixth, and moving on up into the tenth-grade level. For those of you in elementary schools and are unfamiliar with the initiative, what we're trying to do, in the higher grades five through middle school all the way up through tenth grade, is try to incorporate or integrate all of the sciences into science classes, as opposed to teaching distinct branches or disciplines like we used to teach earth science in the eighth grade, physical science in the ninth, life science in seventh grade. We found out that this layer-cake approach wasn't very functional and it wasn't doing our students a great deal of service. By integrating all the sciences, they get these concepts every year and they're to get chemistry, physics, and earth science constantly, as opposed to seeing it one year and then they don't see it again.

Further, that we have a web site and we have this additional information, so let's take time to copy that web site down: www.wvgs.wvnet.edu. We will be gathering information and putting up the information, and the audio text will be transcribed and typed up and put onto the web site. You will additionally have the video tapes available for additional use and reviewing as well as working in the future.

For those having registration problems, please call the WVU Extended Learning Office at 1-800-253-2762. If facilitators or students have questions, call Tom Repine at 1-800-WV-GEOLOgy (1-800-984-3656). The phone bridge dial-up is 1-800-233-3638. Our phone bridge will be available half an hour before the show, and you can talk to us during the video presentation, and then we'll leave it on until 8:30, a half an hour after the show. The reason for that is you may have immediate questions.

Let's talk about the textbook. There is no cost for the textbook. It is covered under the auspices of your CATS registration. This is not a trivial textbook. It's a new edition, Earth's System History, by Steven Stanley. When you get this and start paging through it you're going to say, whoa, what have I gotten myself into? But be of good cheer. What you have gotten yourself into is a textbook that will take you to whatever extent you want in detail. But we will make this very practical by tying in West Virginia geology and history. So, this is going to be a resource book for you. Included in the text is a CD which contains a nice little game you could play with the geologic time scale.

Additionally, there will be handouts. From time to time, which usually means every time we meet, there will be quizzes. And these are quizzes and quiz questions for which there may be no precise answer. Each individual will be working on these but you're encouraged to talk among yourselves before, during the break, or after each of the video presentations. I'll take time each week to go over some of what I'm trying to get at with these quizzes. You will find that in this course, we will lead you from time to time into looking things up in the book or looking back at the tapes. Answers may not just jump right out at you in boldface on page 16. You will have to do some digging. We will give you broad hints and help you if those broad hints aren't sufficient. For example, have you looked at page 152. There may be some very good information on quiz number 3, question 4. That sort of thing. But there are many times where you are asked to work from handouts, the text, or the video.

Let's review the syllabus. The major components are six live satellite broadcasts. There will be three Saturday Exploratories. These are really good fun. In the fall, we ended up with an extra one. It was a marvelous field trip to some of the natural bridges in West Virginia, completely organized and run by the participants in the class. The three Saturday dates are March 20th, April 24th, and May 1st. The sites will be announced. We run from 10 o'clock in the morning till 3:30 pm. The textbook I mentioned. The other is boilerplate information. It reflects the fact that it will be either two or three credits, the expectations, and required work by credit level. All participants will take a pre- and post-test. The main item is this: what you do for two credits. So for two credits, you do the quizzes, and you will get all the quiz materials by the third show. We haven't put all that material out yet until we find out how many copies everyone needs. And there will be one test. It will be an open-book test, but you don't get to discuss it with each other. But you can go back to videos, to the books, to the notes, to the quizzes themselves. That will be distributed later in the semester so that you have about three weeks to work on it and then turn it back into us at the end of the semester.

Dr. Bob: Deb, go over the lesson plan information.

Deb: As the semester progresses, we'll talk a little bit more about what type of format we like to see for the lesson plan. But primarily, since we're involved with CATS, we were trying to push current educational practices. We like to see more of a learning cycle approach--more of your work and less of a copy of something already published I'd really like to see you tie your days together and not have these as kind of isolated activities standing out there by themselves.

Dr. Bob: And we want some linkage to the IGOs, don't we?

Deb: Exactly. We really would like to stay relevant to what you need to be teaching in your classroom. So if we ask you to design a lesson plan, we'd like you to look at your IGOs and see how that concept ties into what you're supposed to be teaching--that this is a useful activity for you.

Dr. Bob: We will work on a graded system of 90 percent and above, A; 80 to 89 percent, B; and so forth. And I could tell you that all folks that enrolled last semester for the CATS course were grades of As and Bs. And we understand that there's a great diversity of where you come from to this course, especially in the context of historical geology. And our general expectation is that this group too will be As and Bs. And there's nothing wrong or no failure to be attached to a B grade. It's just that your on a learning curve and we had to give out a grade before you got to that next level.

Further, for the three credits of Geology 290, we'll do the first component exactly the same, the quiz work for 100. One test is the same. One lesson plan is the same. But for three full credits, you'll also do a field and implementation notebook. Implementation, not only in the field but perhaps also in the classroom. Especially in the classroom, it may link in part of what you do as a lesson plan or some other component. Because the implementation notebook is something that we work on those three weeks when you see Deb, or I, or Tom.

Then the participation in the Saturday events and that's 100 points, and the expectation is that if you're in for three credits, that you will be at three events. Now, we've told you about three formal ones, but last fall, as I had suggested, we wound up with one extra one. There were many people that wound up at all four. Well, they didn't do that for extra points. They thought it was fun going on field trips. It also turned out the fourth one turned out to be a neat field trip for everyone involved.

Deb: Plus it was a chance for anybody who had missed one of the Exploratories to make it up.

Dr. Bob: Exactly. We'll do at least one extra, and perhaps another extra. So we'll have some extra opportunities to go fossil hunting and one really neat opportunity we're working on to look at the plants as preserved in the coal environments in West Virginia in some really exciting outcrops and exposures that are being worked on in the southern part of the state. If you haven't driven the southern part of the state recently, it's an eye opener. The exposures from Charleston down past Logan to Williamson are unbelievable. Unfortunately, they're a little steep to safely navigate. And there's also traffic on the interstate now with a limited access. But we have plenty of locations on access ramps and/or auxiliary cuts where we can get a great deal of very interesting information to share. So, that takes care of that first part of the boilerplate.

Deb, West Virginia topography is different. What did we talk about last semester in comparing and contrasting the eastern part of West Virginia with the two-thirds of West Virginia in the north and west?

Deb: We talked physiographic provinces in the state of West Virginia. And the fact that, although we call it the Mountain State, most of the state is not mountainous. In fact, its a plateau that's been deeply incised by rivers and erosion and water. And so, the bulk of the state is actually a plateau region that is hilly because of erosion. And in the eastern part of the state, due to plate tectonics and the collision of an African plate some years ago, a folding and faulting created our Appalachian Mountains.

Dr. Bob: So that in the context of the dynamics, what we are going to do now in this course is, we're going to flatten it back out. While North America and Africa collided, we're going to undo that. We're going to pull it back and then we're not even going to talk about Africa or North America anymore. We're going to talk about proto continents. And those proto continents are going to receive layer upon layer of sediments. And that's what we're going to do in this course. It's sort of like putting it into reverse. And we'll start at the bottom and work our way up. And that is a law in geology. And what do we call that law? The law of superposition. A great number of you are in facilities that probably have a room or a wall, or perhaps every wall, made up of concrete blocks that are painted. And what you'd be able to do, you'll soon find, is that each layer and level of the blocks can be a different rock layer beneath your feet. We can take the students on a virtual elevator trip down to the basement. You can reconstruct on those walls, probably not paint on it, but we will use those walls to recreate the history beneath our feet. And you're going to find that indeed it's quite deep in places before you get to the basement. And basement is a real term in geology. It's the old stuff, the really old material.

And another term in geology that has come to be used is deep time. To get down to deep time, we've got to go down into the rock sequence. We have a individual here in the classroom who is very much a part of deep time, because one of the classical field trip areas is to go down into the Grand Canyon. That really gives you the impression of deep time. You walk all the way down and then you walk all the way back up.

We'll take a break now to give the facilitators a chance to gather additional information. We'll be back.

(BREAK)

Dr. Bob: Greetings, we're back again. Deb, let's talk about time in the context of two terms that we use in geology: relative time and absolute time. You mentioned the law of superposition. How does that relate to relative time?

Deb: When we talked about relative time, we're really just talking about how something is relative to something else. If something is older or younger then a particular rock unit, we don't put an exact date on it. We just say this is younger because it occurs on top. It hasn't been flipped or moved around since the original position on something below it. We use relative time to get an idea or feel for when something was deposited relative to something else.

Dr. Bob: That means that the courses of blocks on your wall that you're using, the bottom ones had to be laid first. Kids are smart as whips. They can figure that out. But what we're going to talk about is that the mortar in between the blocks is a change. It is a change in the courses of concrete blocks and that happens in real history too. Sometimes the change is erosion. Sometimes it's a change of volcanic ash deposited on the course of blocks. Sometimes the change is mud. A mountain building episode taking millions of years has created more debris that's swept in and covered that course of concrete blocks. In reality, what about the concrete in between the blocks? We're talking as if the course is all consistent horizontally. What about the extra building they added on or another building down the road? There may be changes.

If you had been to a beach or a lake, you realize that there is a shoreline and there is the below water zone and a above water zone. We talk about those in time as aspects of deposition. There's a geologic term that you might as well be introduced to right away. The aspect of deposition is known as one of a number of facies. Facies are aspects of deposition. That's what's happening between the courses of blocks. The mortar might be a facies of the beach. The lake might get a great deal more water and what's going to happen to the beach? It's going to creep up on the sides of the basin. If the water evaporates or precipitation is altered by global climate change and the water disappears, the beach is going to be lower in the basin. The memory of the beach may be in a thin layer of sands deposited and being interpreted as a beach deposit up the hill, and then as the lake goes back down, one of two things can happen. One, if we're lucky, it's buried. It's preserved and we can record the history of it. What probably is going to likely happen is erosion. The process sweeps away the memory.

Fortunately in geology, when we talk about the really big picture, not a lake now, but now we're talking about the edge of a continent, if you continue to load a continent with sediment, what's going to potentially happen as more and more of this very heavy stuff gets deposited? It might start sinking, doesn't it? And then when the water diminishes in the basin, it's perhaps the better opportunity for preserving the rock record.

We're going to find out that the eastern panhandle of West Virginia, and indeed below our feet at every one of the viewing sites throughout West Virginia, received a great load of sediment a long time ago, 500-million years ago, give or take. As all that material was deposited in a warm ocean, the basement rock bowed under the weight. The crust of the earth was depressed by that weight and a record of that remains. The really neat part, if the crust starts to sink, the possibility exists that, as more and more sediment is deposited, more and more material may accumulate because the weight of the sediment causes the earth's crust to subside. This subsidence provides room for even more sediment to deposit. Millions and millions and tens of millions of years of sedimentation and the water depth hasn't really changed much. But the process has allowed for the deposition of not ten feet of sediment but thousands upon thousands of feet of sediment with relatively little change in the environment. Really neat! That's what we're going to get back to into the history. So relative dating are courses of blocks on the wall.

Then you alluded to absolute dating. And how do we accomplish that?

Deb: In absolute dating, we usually have to use radioactive isotopes and half-lives to accomplish any type of radiometric dating.

Dr. Bob: In West Virginia, what types of layers might work?

Deb: We have a small volcanic layer that we can use radiometric dating on.

Dr. Bob: We have in West Virginia and West Virginia rocks a little bit of volcanics in the Cambrian. There's another little episode preserved in the Ordovician. There's one in the Devonian. And then there's a nice layer in the Pennsylvanian. But it's not only radiometric dating here in West Virginia that allows us to say our stack of sediments may correlate or show connectiveness. Connectiveness is another way of defining correlation. We don't always have these nice radioactive layers from volcanic ash or other layers of basalt. There's igneous rock exposed in Pendleton County, but it's very little. It certainly isn't found elsewhere in West Virginia. Occasionally we drill into it, but we haven't found much else when we drill in the other parts of West Virginia.

There's something else that has been preserved in the rock record that allows us to do some absolute dating. And that is? The fossils. It's not just any old fossil. The best fossils for dating reflect species of animals that had a wide distribution, so that we can find them. There were lots of them, so we can find their remains. But some particular species didn't live very long--they had a narrow time of existence but a broad distribution. These kinds of fossils are really important to correlation. They are called index fossils.

How can we get absolute dates with fossils? Someplace in the world there may have been igneous activity so that there are remains of rock that contain the radioactive elements that allow us to get the absolute date by natural radioactive decay. This is called radiometric dating. We'll talk about those later. You know one means of getting an absolute date from radioactive material. That's the carbon-14 dating method. That only goes back about--you can enhance it--70,000 years. But most scientists find it to be real useful back to about 30,000 to 35,000 years, and hope to extend it with very precise instrumentation and collection back into the 70,000 years. So we're always looking for ways to correlate.

What we discuss in historical geology also is relevant to the modern world. Specifically, the demise of some of our living life. If there's one thing that our youngsters can take away, it is that we must have great sensitivity. We hold in our hands the ability to exterminate life forms. We will talk later on of some fascinating new information that suggests since Australia was an island continent and otherwise isolated, animal life forms developed in different ways. You know that already. The kids know it. They know kangaroos. Then humans finally made their way to Australia and when those humans first came to Australia, there still were available what we call megalife: really big life forms. And they became extinct very, very rapidly. It has always been suspected that maybe early humans had a cause-and-effect relationship to those extinctions. Some new evidence is beginning to suggest that one of the things that humans found to be very useful was fire. It's also very damaging. It's possible, very easily, for fire to escape our containment. That escape can cause the loss of enormous amounts of the animals' support system. It will return, but it may not return fast enough to save those animals that are so very dependent upon it.

This brings us to the idea of extinction through time and the opening up of new niches which allow new life forms to dominate. Deb, when you talk about time in the classroom, how can you use the classroom, the football field, the outdoors, and the hallways to talk about time?

Deb: There are a lot of ways that you can model geologic time. As a matter of fact, in one of the Exploratories, we'll be addressing that. We'll talk about models and modeling geologic time in the classroom. Every textbook that even addresses geologic time will represent geologic time as some model. You can use toilet paper rolls. One sheet represents so many thousand years. You can use five meters of adding machine tape. Stretch them out and every centimeter represents a certain block in time. The football field is a good one for the youngsters because they can get out there and run for a hundred yards. They can put little markers out there for geologic time, where humans were, where the fishes came in. I like the one with the movie where you have a movie that lasts a year long. I'll bring that to the Exploratory when I come, but that's a fun one. The kids sit there and you say, you're going to go into a movie that's one year long. You have to bring all these gallons of coke, big bags of popcorn, you're going to sit there and watch the history of the earth in a year-long movie.

Dr. Bob: The age of the earth is 4.6-billion years. Modeling that requires a lot of anything stacked up, whether it's seconds, this is years, you see. If you use sheets of paper, that's a good one too. A ream is 500 sheets stacking up. If a sheet was one year even, how tall that would be? I am very keen at any level of dovetailing mathematics with our science. Have them figure it out. Later on we'll do an exercise where we'll create the Atlantic Ocean, the width of the Atlantic Ocean.

Speaking of that, one of my pet peeves is that we don't expend money on globes anymore to see the true shape of continents. We have to distort some continents in some way in order to get it on the flat screen, unless you do something like Buckminster Fuller and his geodetic dome. He put a globe on that and then he spread the globe out on each of those pieces. So it looks funny when you open it up and spread it out. But it makes a lot of sense because most of the continents are about the right shape. So except for having a globe in front of you, if you look at the traditional portrayal of North American and such, Antarctica is just this big white blob all across the two pages of the atlas. Greenland is huge, and it really isn't. So that the distortion necessitated by a map projection is something that we need to return to a really nice globe. Or a globe that we can let the air out of or expand and see what happens and have things that move around on the globe. We try to do some of that in portrayal in some of the interactive web site and CD-Roms, but it doesn't always come across.

Well, a couple other comments. It's time we learn some geologic time terms. For now, I'd like you to become familiar with Precambrian, Paleozoic, Mesozoic, and Cenozoic.

The Cenozoic is expanded and blown up to larger size here. Precambrian sounds like something before the Cambrian, and lo and behold that's what it is. Paleozoic--these are old looking, ancient looking life forms--paleo equals ancient, while zoic equals life. So Paleozoic means ancient life. Mesozoic is middle life. It contains many forms in transition. Cenozoic means recent life. There are many of these forms that have close ancestors. Even if some are extinct, there are many, many close ancestors in the genus level.

So we are going to start building our geologic time scale of the planet Earth. So tune in again next week. Keep looking at those fossils, and stay safe. We'll see you again next week for show number two, CATS Historical Geology. Take care!

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

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