Dr. Galloway: I'm happy to say "hello"! I'd like to introduce what I do. I've now had several decades of experience--primarily in understanding the sediments of rivers and other settings--to apply that to the geologic record, so we can understand how the rocks themselves were deposited. And perhaps from that, we can improve our ability to use the resources found in those rocks.

Dr. Galloway: There are several ways. Primarily, from my point of view, I'm interested in looking at rivers and their history. Engineers and hydrologists would pay more attention to the water--the currents, the velocities, and the chemistry. I look, primarily, at the sediments of the river. When I'm looking at younger rivers, I'm interested in understanding their history, such as their very recent history, where man's activities may have affected the river, and older history, perhaps, going back many thousands or tens of thousands of years. Our rivers have changed greatly in Texas, for instance, in the last ten to twenty thousand years, because of the great change in climate as we left the last glacial age behind, and the world evolved into the modern world that we know.

Dr. Galloway: My answer will be more in the area of ground water, rather than modern river water. A number of years ago we learned in studies of ground water in the Texas coastal plain that the same sands that produce water used in agriculture and many small towns also came from sands that naturally contain deposits of metals, including uranium. Some of those well waters were contaminated by radioactive material, and, globally, by those metals. We didn't know this until we were actively exploring for uranium deposits as a result of surveying the ground waters. A number of wells were shut down, because the natural metal deposits that occurred in the sands contaminated the waters.

Dr. Galloway: As a geologist, I would naturally have to say, "Yes." Geologically, the thing I'm always most interested in is going to be the background in which a sample is taken, or a river. That would mean, for example, I'd like to know if it's a bedrock river. In other words, I'd like to know if the riverbed is hard rock, if the riverbed is sand, or if the riverbed is muddy. The simple answer is to make notations about where in a river and what kinds of sediment for the riverbed are used. Knowing whether the riverbed is rock, sand, or mud may help us understand the results of our sample.

Dr. Galloway: Because I am mostly interested in sediment, our first tool is simply the tool of observation and description. What do we see when we look at the river? The second tool is samples, and that may be as simple as digging up a few handfuls of sand. More complicated, we may take a short core sample of the sediment of perhaps 10, 20, or 30 feet down to look at the buried sediments of the river. One of our more challenging jobs is to actually date the sediment that we look at, and for that we may use the tool of radio-carbon dating, or other techniques that give us the age of the sediments. We can also use very young fossils--the bones or remains of living or extinct animals. We can also use archaeological samples.

Dr. Galloway: Yes, there is. In rivers, it's pretty simple. The primary control on the river, whether it is going to be gravelly, or sandy, or muddy, will depend on the kind of rock found along its tributary. As a simple example, for those of us in Texas, most people would know the Brazos River. The Brazos River is usually muddy, and the water looks a little red in color. The reason for that is that the Brazos River drains an area where we have older rock, which is muddy and naturally red.

Dr. Galloway: This is a dangerous question to ask any geologist! You may hear a lot more than you ever wanted to hear. I will try to be short. The primary project that I'm involved with now has as its goal creating at least a broad picture of the last 60 million years of history for the Gulf of Mexico. I am including everything from the rivers and coastal plains, all the way to the deepest part of the basin, which oceanographers call the Abyssal Plain. What we are doing is rather like drawing a series of geographic maps that would show how the Gulf of Mexico has changed over the last 60 million years.

Dr. Galloway: Here in Texas, I can't think of any rocks that have particularly bad effects on surface water. We do have one problem, and I think it is shared by other Western states. In some areas, we have shallow ground water that comes to the surface and provides part of the inflow for some of our rivers. Many times, this ground water, in dry climates especially, will be salty, and, because of that, some of our river water in Texas is salty, and that it is a problem.

Dr. Galloway: Well, I have to start by saying I'm not, primarily, an environmental geologist. I have worked a lot with the oil industry, and it uses a lot of what I do. The Gulf of Mexico is, undoubtedly, the most developed basin in the world for oil and gas production. In my experience, the effects have been very, very small. Again, because I practice geology from the point of view of long periods of earth history, one of the things that I have found in looking at sediments that were deposited along beaches of the Gulf as much as 30 million years ago is that we also find tar, just as on the modern beach. Tar deposits occur in these ancient beaches. One of our realities in the Gulf is that a lot of oil seeps naturally to the surface, and it has been doing it for tens of millions of years. So we do find a lot of tar and tarry material in our modern beaches. In the last twenty years or so, there has been a great effort in the offshore platforms to prevent any spillage of the oil. I think it has been largely successful, but we will continue to find tar, because it naturally seeps out from the floor of the Gulf.

Dr. Galloway: Well, I should start out by saying that I got into geology, in part, because I collected things, including fossils. The neatest fossil that I found, I think, was the tooth of a mammoth, and that's partly because it is really big. It's probably about twice the size of a telephone. I found it in river deposits that were exposed by a gravel quarry here on the Texas coast.

Dr. Galloway: There are two parts to the question. Basically, my work does two kinds of things. One is that I try to develop general models for sand bodies that serve as aquifers for ground water. By that, what I mean is that I try to provide hydrologists and hydrogeologists with an understanding of sizes, the shapes, of the connections of these sands that act like pipelines for the water. So that's a general thing. Secondly, or more specifically, I have been involved in projects, as I mentioned before, where we were looking at large aquifer systems. First, we do this to understand their natural conditions. Secondly, it is to attempt to understand how such things as mining might affect the waters in those aquifers.

Dr. Galloway: (chuckle) My answer would have to be the Colorado River. Next, I have to say this is not the Colorado that made the Grand Canyon. This is the even more important Colorado River that flows through Austin, which happens to be my home. The reasons are several. The first is that the Colorado has nice, clear water; it is not a muddy river. We have some very beautiful lakes and some very good fishing. So part of my answer doesn't have much to do with geology! The second reason the Colorado is my favorite is that it has been studied extensively, and it has a very interesting and complex history, which has been studied in quite a bit of detail by co-workers of mine. As a geologist, any time we can look back and reconstruct old landscapes and see how they've changed, it is always, to me, very interesting.

Dr. Galloway: I started out collecting rocks at a very, very young age; as far back as I can really remember. I was interested in natural things, and I was interested in rocks. So like a lot of geologists, I started out as a collector. I continued right on through high school. However, like many geologists, when I went to college, I got diverted from what I always thought would be the thing I wanted to do. I spent one semester with the idea I was going to become an engineer. By the end of that semester, I had decided that engineering didn't really seem like it was going to be that interesting until maybe my senior year. For reasons I don't remember, I was, once again, inspired to major in geology, and so I did. In my second semester, I found I was having fun, so I pretty well knew that that was what I wanted to do.

Dr. Galloway: Geology and geologists do a lot of different things. I would have to say that some of the things my fellow geologists do I don't find very exciting. What I do, and what I thoroughly enjoy, is being a geographer. We have a bigger word for it, which is being a paleogeographer. By that, what I mean is that I like to look at rocks and reconstruct the geography, the environment, and the processes in which those sedimentary rocks were deposited. One of the favorite points in a project for me, usually near the end of the research work, is to draw a map as if I were drawing a map for an atlas. This would be a map that would show the rivers, the coastline, perhaps the Continental Shelves, the Continental Slopes, and the deep sea fans, as they would look if we could get in a time machine and go back, perhaps, a million, ten million, or a hundred million years.

Dr. Galloway: Geologists have always felt very, very central to the development of natural resources. My own history is a good example. More specific than trying to say what, arguably, geologists could say is everything, I have looked at, first of all, finding and developing hydrocarbons, oil and gas, using and protecting ground water, and discovering, locating, and mining of certain kinds of ore deposits, including copper and uranium. The principal resource that I have left out of that that I have not been personally involved with is coal, but geology and geologists are widely used for that energy resource as well. There is a bumper sticker that is a little bit of bragging, but it is not too far off. In fact, I think I saw one just in the last couple of days. It read, "If We Don't Grow It, Then A Geologist Finds It."

Dr. Galloway: I think, probably, the most interesting thing (and this is more in concept than a physical thing), is the realization that came to me when I was working fairly early in my career, which is that by understanding how ground water moved through aquifers, naturally, I could much better understand why different kinds of metals, including copper, lead, and uranium, occurred in those aquifers. The reason that that was exciting to me, and that I particularly remember it, is that we were trying to look at the rocks as they exist right now, and find correlations that would let us predict where we would find ore deposits. It wasn't working very well. Recognizing that these metals were actually being transported and deposited by water allowed us to understand that there was a dynamic part of the history, and we had to try to look back through time and reconstruct that history in order to make the predictions that we wanted to make. We still don't do it perfectly, but, to me, that's the challenge that makes geology particularly interesting.

Dr. Galloway: Okay! That's a good question for a professor! The last on the list was terrigenous; I'll start there. Terrigenous means that it's a kind of sediment composed mainly of silica, or silica containing minerals, and we contrast that to carbonate sediments, limestone, where carbonate rather than silica occurs. Simply stated, quartz sand is terrigenous sediment. River sand is terrigenous sediment. The first word, pelagic, means sediment that, literally, rains down out of the oceanic water. Pelagic sediment is actually biological in origin. It is the tiny shells of various sorts of microorganisms that live in the ocean. Hemi-pelagic is a little bit of both of the two things I just described. Usually, it consists of some terrigenous mud--real fine grain material that floats in the water for long periods of time--plus some of the pelagic material, as well.

Dr. Galloway: Artificially made reservoirs can and do collect sediment, and, on many long time spans, most of our lakes will fill with sediment. They are doing it now. However, for most of them, the time it will take to fill up will take much more than 50 years. It will depend on the size of the lake and how much sediment the river that flows in to the lake brings every year. It will be a long-term process.

Dr. Galloway: I'm going to presume the question had to do with fossils, or material that was derived from plants or animals. The first answer is that geologists have some general knowledge that will allow them to recognize common things. I'm not a specialist, but when I found the mammoth tooth, I knew what it was. I knew pretty quickly what I had found. There are specialists, however, paleontologists, whose primary expertise or job is to recognize and to identify both animals and plant remains. There are a lot of specialties in there. One paleontologist may study things like mammoths, vertebrates, or larger mammals. Another paleontologist may be a specialist in various sorts of plants or shells. Of course, it is a different specialty to identify plants. For the specialists, even very small or fragmented remains can usually be identified for what they are, and can often help to provide a date or an age, particularly if they are extinct, or no longer present.

Dr. Galloway: (chuckle) The Gulf project has an interesting history. The real answer is that we'll never be finished. The specific project will come to an end, but we'll never be able to look back and see a perfect picture, with all the details, accurately. What I tell students is that what we do is an approximation, at the very best, of the reality. If we do our job well, our approximation will be better than the last approximation that another geologist, or another team of geologists, could put together. Now, the specifics for the Gulf project, because its history is probably typical of many large projects in geology, or, in fact, science. In the beginning, we thought we could do a good approximation in three years (a large basin, a long period of time). We were trying to do a general picture. At the end of three years, the results were so sufficiently interesting that many of our sponsors who provided the financial support for the project wished to continue, and to expand on what we had done. We created what we called Phase II. We proposed and proceeded with what we called Phase II, which was two years of additional works, building on what we had already done. From that, we, in fact, found further ongoing interest, so we are now in what we call Phase III--another two-year extension. We are continuing to refine our original conclusions, and we are adding additional kinds of information that weren't collected in the first phase of our project. In total, our project, which started out to be a three-year project, will be a seven-year project.

Dr. Galloway: I know almost nothing about Lake Tahoe, other than it is spectacularly beautiful, and, geologically, it is a very interesting place. There has been work done that I have read in the last few years where geologists from the United States Geological Survey have used the tools that oceanographers used to create images or pictures that are like aerial photographs of the underwater parts of Lake Tahoe. To me, what's extremely interesting is that we see the same kinds of things, such as submarine channels and submarine landslides, which we see in the oceans. In many ways, Lake Tahoe is very much like a tiny scale model ocean base.

Dr. Galloway: I think anybody who is interested in natural sciences and history would be, potentially, very interested in geology. The best preparation to become a geologist is to be strongly based in all of the major sciences--biology, chemistry, and physics. Geology uses parts of all the sciences. In that way, a geologist is kind of a generalist, or a 'Jack of all trades'. I think very important preparation for anyone interested in geology is to get a broad background in the sciences. Beyond that, like most sciences these days, geology is becoming more quantitative. And although I am not a mathematician, mathematics, including higher levels of math like calculus, plays an increasing role in the work that geologists do. So you have to be brave enough to tackle some math. We are really no longer just the verbal subjects.

Dr. Galloway: I have a really simple answer to that. The answer is yes! Geology finds a lot of applications. My experience has been, primarily, in applications by industry, and applications by both state and federal government. For ten years before I became a professor, I worked for the State Geological Survey of Texas. There is also, particularly in Northeastern states, a lot of application of geologists for engineering purposes. Siding dams, digging tunnels, and locating bridges, all require geological tests to make sure the engineering is appropriately designed for the kinds of rocks that are going to be the foundations for those projects. And, of course, an increasing use of geologists is in the area of both ground water and surface water. And there, too, the answer is really yes. Government, federal and state agencies, obviously, has some concerns for water management. Private companies are very much involved in developing water resources, in remediation of wastes, or contamination, and geologists are used there as well. So my simple answer has become a complex answer. Yes, geology finds a tremendous range of uses.

Dr. Galloway: I think the numbers tell us that fossil fuels--oil, gas, and coal--will essentially provide the energy we need for, at least, several more decades, but the long term answer is, of course, that they are used up. They will be depleted. As a global society, and, certainly, as a country, we will sooner rather than later have to start that evolution towards the use of renewable resources, and the use of hydrogen or another kind of non-carbon based energy economy. So the answer is that we will be putting gas in our cars for many years to come. We will be using natural gas and coal to generate electricity and heat our homes for years and decades to come. Although there are arguments over exactly when, the end of the fossil fuel era is in sight, and we will evolve to other energy sources in the coming decades.

Dr. Galloway: For someone who is interested in the earth, natural processes, how they work, and not daunted by having to think in terms of not years, but perhaps hundreds, thousands or millions of years, I think geology is certainly an exciting area. I have enjoyed my career in the geo-sciences. We will need lots more geologists for the next generation. Beyond that, I hope everyone realizes that our natural landscape is basically a geology textbook. Every time you look at a river, drive across a mountain, or go to the beach, you are experiencing geology, whether you know it or not. Geologists have this dream that more and more people will realize that they are looking at geology as they go about their day-to-day lives.