A comprehensive rebuttal to the Expanding Earth Theory: Part 1
Although this may seem quite silly to a lot of you, there is this increasing dialogue about a theory that counters the theory of plate tectonics. This theory is called the Expanding Earth Theory (EET) and postulates that the Earth has not been the same size throughout time but started out with a radius of around 1,700 kilometers in radius and grew into the radius it is now, approximately 6,371 kilometers. This blog will fill the oddly apparently void of a point by point rebuttal of the EET by means of structural geology, geophysics, and sedimentology.
This will be in a series of parts as it is very time consuming doing this and it takes days of preparation and research to produce only a few pages.
There are two main videos from some of the more prominent EET advocates, James Maxlow and Neil Adams. Their videos can be found on YouTube, and as these two videos are a congolmeration of the main points of the EET, I will be doing a step by step rebuttal of the James Maxlow video and then writing about the unique points of the Neil Adams video. The James Maxlow video can be found here: https://www.youtube.com/watch?v=ePyU7cyMT_k There are a lot of points of contention in these videos and I could go on for days about it, so in this blog I will be highlighting the main points of rebuttal that can be proven by physics and geology.
First we must understand the basics of the EET. It is a theory that states that the Earth had a much smaller radius than current day and that the Earth has been expanding through time on an exponential increase. This is detailed by the spreading rates and ages in the mid-ocean ridges, the apparent exact fit of all continental edges if the radius of the Earth was smaller, and the apparent inconsistencies in mantle dynamics and the sedimentary record.
The first 10 minutes of the Maxlow video is a basic introduction of the EET including the basic premise and the history of people that recognized the margins of the continents were matching from margin to margin. This introduction shows that this is not a new idea that has crossed the minds of people and is in fact something that looks plausible and logical due to the visual configuration of the plates. At around 7:15, he says that his reconstructions go back 100% of Earth’s history and that Plate Tectonics ‘struggles’ to get to 20% and is ‘not convincing’. Although true that modern plate reconstructions only can be made accurately for around 750 mya, this is not due to a lack of evidence for the mechanism of plate tectonics but merely because the surface geology of the continents, erosion, collisions and basin formations obscure a lot of history that far back.
I will now list the claims set forth by the EET and my rebuttal.
1: Coastlines of the continents must remain constant in order for the EET to function.
This line of reasoning is shown in the first 10 minutes of the James Maxlow video (or alternatively you can skip to the last 5 minutes of the video where he has his models running). This is also something that is repeated several times in the Neil Adams video, namely that if you take the existing coastlines of the world, take away the oceans and decrease the radius of the Earth, then everything will fit together.
If we look at some recent articles and books such as Fromard et al., 2004, and Boggs, 2006 (figure 1) we see that the coastlines of continents are highly variable and can be altered on the order of years and even weeks such as the case of Hurricane Katrina in the southern United States (Sallenger et al., 2007).
Figure 1: Maps of coastline changes over the course of 36 years (1951 – 1987) compiled from satellite images and aerial photographs of offshore French Guiana (Fromard et al., 2004)
Another example of how the margin lines of continents can be highly variable throughout time is the occurrence of large coastal sedimentary deltas. Large river systems such as the Mississippi and the Nile transport an incredible amount of material downstream, with the Mississippi transporting 230 million tons of sediments per year (Jansen and Painter, 1974, Mead, 1982; Meade and Parker, 1984; Ludwig and Probst, 1998). This massive amount of sedimentary transport results in the increase in shoreline area and in the case of Louisiana, an entire area for agriculture and residence (figure 2)
Figure 2: Lobes of the Mississippi delta which allowed for a localized area of land ( image courtesy of wikicommons)
Once we realize that the coastlines of the continents are not only easily altered by sediments from rivers but from tectonic activities such as the compression of the Himalayas, we can confidently say that the margins of continents cannot stay static for the 4.6 billion year history of the Earth.
2: The rate of expansion in the present-day is 22mm increase of radius per year “ John Maxlow”
For this problem, we need to make a comparison. If the radius of the Earth is increasing by 22mm per year, then this needs to be proportional to an increase in the surface area of the Earth. Let’s calculate that now:
where 6,371,000meters is the current radius (approximately) and 6,371,000.022 is the increase of 22mm.
Lets now take a look at the three major mid-ocean ridges and their spreading rates:
Mid Atlantic Ridge: 10,000 km in length, median spreading rate of 3 cm/year.
Pacific Ridge: 5000 km in length, median spreading of 15 cm/year
South East Indian Ridge: 6700 kilometers in length, spreading rate of 15 mm/year.
These are just the major spreading ridges and by no means represent the sum total. We can assume that the area amount of the total amount of area ‘created’ by the spreading ridges each year must be equal to the surface area increase we calculated before for the radial increase of 22mm.year.
To calculate the ‘increase’ of surface area from these spreading ridges, it is a simple length*width calculation. If we calculate this, we end up with:
Mid Atlantic Ridge:
Pacific Ridge:
South East Indian Ridge:
The addition of only these three areas is 
3: Subduction does not exist.
This is the main idea and parading ‘fact’ of the EET. There is no subduction of the oceanic crust under the continental crust on active margins (although they don’t distinguish between active and passive margins).
Firstly, subduction zones are not just a concept that is present only on paper. To understand how we can see these subducting plates, we need to understand what seismic tomography is. A tomographic image is merely a map of P-wave (or compression wave) velocities. Think of it this way, if you and a friend are on opposite sides of a long table and you punch the edge straight on, they are going to feel the movement very very quickly. If you do the same but with a block of jello, if they feel anything transmitting to the other end it is going to be a very small amount. This is because P-wave velocity is a function of density. The more dense something is, the faster P-waves will transmit through that material, excluding things like the outer core which are plasticine and dense so they don’t transmit the compressional waves very well (figure 3). This means that using seismic wave velocity contrasts will give us a picture of the density contrasts (Zhao et al., 1997; Fischer et al., 2000; Roth et al., 2000)
Geophysicists like Robert van der Hilst at MIT have imaged the subducting oceanic plate using seismic tomography (figure 4) across Central and South America showing that not only can geophysicists image the subducting plate, but they are able to determine the angle in which they subduct and anisotropies in the subducted plate segment.
Figure 3: P-wave tomographic image of the Tonga Subduction zone from Zhao et al., 1997. This image is a compilation of ~41,000 P-wave arrival times from 926 earthquakes. Red in this image show slow velocities (such as the less-dense more buoyant continental crust) and blue denotes faster velocities (such as through denser materials like oceanic crust; Wiens, 2000).
Figure 4: Differing angles of subducted oceanic plate on the Central to South American active margin.
Another major component of understanding the relationship between the surface geology of the Earth and the presence of subduction is the geochemical make-up of the magmas on active margins. An active margin is where subduction is taking place. This subduction creates compression (mountain building) and volcanoes (which I will get to in a little bit). The most obvious place to see this phenomena is on the Pacific Ring of Fire (figure 5).
Figure 5: Relationship between subducting oceanic plate and the occurrence of volcanoes ( Topinka, 1997).
This is a very important distinction. In the EET, there is no reason for these volcanoes to exist in the places they do and it takes absolutely no mention of the geochemical differences in melts produced in these volcanoes. The reason that there are so many volcanoes near a subducting plate is because of the interaction of the chemistry of the subducting oceanic plate and the mantle in which it is being subducted into. This is the reason there aren’t volcanoes everywhere on the planet because there isn’t this unique geochemical interplay (figure 6).
Figure 6: Note number 12 where there is an area of melt associated with the interplay between the asthenosphere and the subducted oceanic crust. This is due to the mixing of geochemistries which lowers the temperature for melting. Think about putting salt on ice, it lowers the temperature in which the solid ice will form (from volcanoes.usgs.gov).
In the next installment I will cover the structural geology aspects of the EET, namely what happens structurally if you have a sphere that is increasing in diameter that has a solid outer crust and what features we should expect to see in such a system along with how we know the Earth isn’t a piece of the Sun that was shed off (another claim by the EET).
References and links
Fischer, K.M., E.M. Parmentier, A.R. Stine, and E.R. Wolf, Modeling anisotropy and plate-driven flow in subduction zone back-arcs, J. Geophys. Res., 105, 16181, 2000.
Fromard F, C Vega, C Proisy, Half a century of dynamic coastal change affecting mangrove shorelines of French Guiana. A case study based on remote sensing data analyses and field surveys, Marine Geology, Volume 208, Issues 2–4, 15 August 2004, Pages 265-280, ISSN 0025-3227, 10.1016/j.margeo.2004.04.018.(http://www.sciencedirect.com/science/article/pii/S0025322704001112)
Jeff Lillycrop and C. Wayne Wright and Asbury Sallenger, Coastal-Change Impacts during Hurricane Katrina: An Overview, Coastal Sediments ’07 chapter 68 pages 888-896
Jansen, J. M. L., and Painter, R. G. 1974. Predicting sediment yield from climate and topography. J. Hydrol. 21:371–380.
Ludwig, W., and Probst, J.-L. 1998. River sediment discharge to the oceans: present-day controls and global budgets. Am. J. Sci. 298:265–295.
Meade, R. H. 1982. Sources, sinks, and storage of river sediments in the Atlantic drainage of the United States. J. Geol. 90:235–252
Meade, R. H., and Parker, R. S. 1984. Sediment in rivers of the United States. U.S. Geol. Surv. Water Pap. 2275: 49–60
Robert van der Hilst 2007 http://www.geotimes.org/july07/article.html?id=feature_deeper.html
Roth, E.G., D.A. Wiens, and D. Zhao, An empirical relationship between seismic attenuation and velocity anomalies in the upper mantle, Geophys. Res. Lett., 27, 610-604, 2000.
Topinka, 1997; http://oceanexplorer.noaa.gov/explorations/05fire/background/volcanism/media/tectonics_world_map.html
Zhao, D., Y. Xu, D.A. Wiens, L. Dorman, J. Hildebrand, and S. Webb, Depth extent of the Lau back-arc spreading center and its relationship to the subduction process, Science, 278, 254-257, 1997.
http://volcanoes.usgs.gov/about/edu/dynamicplanet/nutshell.php
Today, we’re going to talk about the new documentary that was released by Josh Fox, the creator of Gasland, which is named The Sky is Pink (link here: http://vimeo.com/44367635).
The documentary is full of deception, half truths, and outright lies that are peppered in between faux-artistic camera work and a narrators voice that is seething with propaganda and a wish to appeal to outrage culture that has been cultivated against oil companies,or any industry that can be prefaced with BIG, pharma, agrochemical etc. or any kind of energy sector company that isn’t working with solar panels which the creator of the documentary seems to have an affinity for, flashing to images of them throughout the documentary.
The video starts off with an interview that Tom Ridge did with the satirical Stephen Colbert about the dangers of fracking and what it means to have peoples’ tap water having the ability to combust. Tom Ridge explains how methane is a naturally occurring gas and has ended up in water wells for the vast majority of history. This is very true, however, the one thing that Tom Ridge fails to explain is that although there is methane within most of the water-wells throughout the areas where natural gas is naturally occurring, the concentrations of the methane are different.
A 2010 article by Osborn et al, found that methane concentrations in water wells in an area of active fracking have ~17x the amount of methane concentrations within the aquifers. This is well above the EPA designated safe concentrations (figure 1)
Figure 1: Methane concentrations (mg CH4/L) as a function of distance to the nearest active gas well (active wells designated by a closed circle, non-active by open triangle) Osborn et al., 2010)
However, in the same article, there were no reported ion and isotope contaminations within the aquifer water itself (Osborn et al., 2010) and confirmed by an independent article by the Ground Water Protection Council (http://fracfocus.org/sites/default/files/publications/state_oil__gas_agency_groundwater_investigations_optimized.pdf) and EPA administrator is quoted as saying “in no case have we made a definitive determination that the [fracturing] process has caused chemicals to enter groundwater”
This means that although there are instances of higher methane concentrations (along with the longer-chain hydrocarbons like propane and benzene) there is no physical contamination from fracking fluids. This indicates that there may have been a casing failure deeper within the borehole, or, the fracturing process has managed to tap into some of the existing fractures within the area and it allowed gas to flow along a network of natural fractures, thus contaminating the aquifers.
This is one of the main problems with fracking the ground to extract gases. There are vast networks of pre-existing fractures that are naturally occurring. They are impossible to map using current technologies, so creating a new fracture network may lead to communication of gases with a pre-existing fracture network. This can lead to gas infiltration into aquifers. This also explains why there might be a gas contamination and not a physical fracking fluid contamination: the gas will have a much easier time travelling through this fracture network, where as the fluid, being much more viscous and dependent on higher pressures, will not travel as far.
In the first few minutes of the program, we begin to understand the basic problem of the debate and controversy with fracking: deception on both sides and objectivity lost in the name of either a greater cause, be it money or humor, which only further divides people on the subject.
At around [02.10] into the documentary, they flash to a cross section, that is not to scale, thus showing a closer proximity of the gas fracking to aquifer than truly exists, of a drilling rig and shows how fracturing is done. Just to be thorough, I will point out at this moment that there was no mention of surface casing or production casing, nor was it accurate in the depiction of how fracturing is done. In the animation they show, there is no mention of casing. Casing is where layers of steel piping and concrete are installed into the borehole (or well) to prevent any loss of gas or oil. A further explanation of the different types of casings can be found on the Wikipedia site here http://en.wikipedia.org/wiki/Casing_(borehole)
The film then flashes to a few quick images of the chemicals used in fracking, one of them stamped with [PROPRIETARY]. Fox tries to make it sound like it is impossible to get a list of these chemicals, even though he flashes them himself on the screen (and the reason he flashes them so quickly is because most of the chemicals are things that are found in laundry detergents, food preservatives, other industrial activities that are not required to regulate, nor disclose their processes or particular chemicals). If you want to take a look at the chemicals and find out what they are used for, please see http://fracfocus.org/chemical-use/what-chemicals-are-used; http://democrats.energycommerce.house.gov/sites/default/files/documents/Hydraulic%20Fracturing%20Report%204.18.11.pdf; http://assets.bizjournals.com/cms_media/pittsburgh/datacenter/DEP_Frac_Chemical_List_6-30-10.pdf.
It would be useful to first know what fracking fluid is composed of: 99.5% of the fluid is water, around 50% of what is left of the 0.5% is known as a propant, or something like sand or silica to keep the fractures open after fracturing takes place (so that the fractures don’t close up and the gas has an easier time percolating through a fracture network that is propped open), and the rest is composed of the various chemicals. It is an extremely low percentage of the fracking fluid, and there are many regulations that dictate what happens to waste waters once it is extracted from the well (http://cce.cornell.edu/EnergyClimateChange/NaturalGasDev/Documents/PDFs/marcellus_regulations_fact_sheet%5B1%5D.pdf)
[02.30] again states that there is a public health crisis, however there is never any substantiating evidence or links to references about this claim and I was unable to find any article that discovered a higher amount of illnesses that would constitute a crisis within the communities surrounding a well. In studies, especially medical studies, there can always be false correlation/causation trends that can be inferred. Much more study is needed in this specific area to determine what is the exact cause of the illnesses.
[02.41] “ …it is a whole-scale industrialisation” Yes, the oil industry is. . . an industry. Using the word “industrialisation” to scare the public is, again, being deceptive. This type of language is also used earlier in the documentary, and the effect that it has on the audience is damaging to objective discussion, it hinders legitimate issues and over-emphasises illegitimate arguments and makes any type of debate very adversarial.
[02.50] Fox then describes a point in a rebuttal article about his original film Gasland about the claims that the man being able to light the water on fire were, in fact, true, where the gas industry rebuttal says that it is naturally occurring methane. Again, please refer to the interview with Tom Ridge earlier to see what the effect of not recognizing that there is a natural source for methane in aquifers has.
I do find it highly suspicious that Fox would pick on one of the more easy-to-prove points in the rebuttal rather than going after some of the scientific falsities that were pointed out.
[03.19] The interview with Doug Sheilds is a very interesting point. The way the documentary wants to put it, is that they took trucks full of mud and radioactive material and dumped it into the rivers, however that is not what happened. The waste water was transported to the local sewage treatment plants, treated, and then released into the river water. The problem is that the water was slightly more radioactive due to the shale particles that were suspended in it http://www.newsinferno.com/fracking/dumping-of-radioactive-fracking-waste-in-pennsylvania-waters-creates-uproar/29221. Again, this is an outright lie on the part of the documentary maker. This is a problem that would absolutely be solvable, with minimal investment, by updating the sewage treatment plants. Almost all oil companies are willing, and usually are the forerunners in investments for public services. This is something that can be compromised on: Have the oil companies pay for retrofitting sewage treatment plants for the return of being able to use them for cleaning up fracking waste-water.
[05.45] The documentary then goes into a tirade about how the tobacco companies hired Hill and Knowlton to smooth over the controversy with cigarettes causing cancer. He then goes on to say that the ANGA, or American Natural Gas Association has also hired this firm. Full stop. Lets take a look at who else Hill and Knowlton represent: The American Heart Association, Arby’s, Center for International Disaster Information, Embassy of Japan, Florida Hospital Assn., GlaxoSmithKline, Kidney Care Partners, Kellogg Company, Motorola, Nuclear Energy Institute, Reebok, Virgin Mobile, and Wal-Mart to name a few. There is an entire list here http://www.sourcewatch.org/index.php?title=Hill_%26_Knowlton#Clients. If we’re going to be judging companies and industries by the PR firm that they hire to represent them, lets lump every other company that is represented by that firm into the same group. If you don’t do that, you’re just being disingenuous.
[06.08] This part really gets me. He is talking about “big tobacco all the way to climate change” in which he zooms in to some text that says “no proof” right after he says climate change, but that document is in reference to tobacco, not climate change, and it is in just a few square inches of some document that we don’t know the origin of.
[06.41] When the woman here is saying that people don’t know if methane is naturally occurring in tap water, and that the PR firm of Hill and Knowlton is trying to fabricate a debate on where the methane is coming from, this is again a falsity and out right lie. It is proven, by empirical data cited earlier in my argument that methane is naturally occurring in tap water. The whole conversation with the woman, complete to the end, is a false representation of the data, and has manipulated, or even outright lied about, the data to further fit his agenda. The minimal levels found in non-active well areas can be seen in Figure 1 above.
[07.30] When Fox states that “the oil industry has documents in their drawers” insinuating that these documents have never seen the light of day and that it takes a massive undertaking to get these documents, it is just preposterous. Here are the exact papers he was saying “fell off the back of a truck”: http://www.scribd.com/doc/65704543/Casing-Leaks; http://www.slb.com/~/media/Files/resources/oilfield_review/ors03/aut03/p62_76.ashx; http://www.heritage.org/events/2010/11/hydraulic-fracturing; http://www.spe.org/spe-site/spe/spe/jpt/2007/07/106817Syn.pdf; http://www.energyindepth.org/wp-content/uploads/2012/06/Archer-Copy-for-EID.pdf. All of the information is in public domain, all you have to do is look. Read the sources yourself, and you’ll notice another trend: Most of the information that Fox is spouting is extremely warped, or it is from models, not from real-world example. Models, in almost every natural science, have major limitations, especially when implementing those model results into the real world.
[09.30] With the ever present flair for the dramatic, Fox states that wells and their casings need to last ‘forever’. This is also fallacious. Abandoned wells are routinely either completely cemented, or more commonly have cement plugs placed throughout different levels in the wells to mitigate any transference of material from layer to layer. All of these different protocols are detailed in the Energy Resources Conservation Board Directive 020 about well abandonment http://www.ercb.ca/docs/documents/directives/directive020.pdf. This again shows a fundamental ignorance about the lifecycle of a well.
This is not to say that sealed and cemented wells cannot leak, it is just highly improbable.
[11.48] When Fox says “there’s no way to fix it” in reference to leaks in casing (again, we’ve already established that methane and other long-chain hydrocarbons can leak into aquifers via casing failures or from unknown fracture propagation) it is also deceptive and a slight to the science of geotechnical engineering and petroleum engineering. Nothing is impossible, and there will be a way to fix these problems, it will just take more years of science to figure it out. There are currently several disciplines within geology that are dedicated to figuring out these exact problems, and the usage of more and more sophisticated models and mathematical constructs are being utilized
[11.52] “ …there’s no safe drilling, and they know it]. Again, a fundamental mischaracterisation of the science, and of the overall impression that is given by geologists and engineers. Geologists, mathematicians, physicists, chemists, and engineers are working extremely hard on solving these problems. They know it is possible to have safe drilling, it’s just a matter of finding the right answer.
[11.58] When Stephen Colbert lists some chemicals that are found within fracking fluids, he tries to make the point that he wouldn’t be able to feed them to his toddler. Lets look at them in an objective viewpoint:
Kerosene: Used for insecticides, fire-breathing, and cooking. If he has taken his daughter camping, chances are she’s been exposed to kerosene.
Benzene: This is an additive of gasoline, so chances are, she has been exposed via Stephen filling his car with gasoline in the way of fumes, or if he will make her mow the lawn and fill the gas tank when she gets older.
Urea: Well, that’s produced in the human body, so I’m fairly sure she’s been exposed to that.
Toluene: This is used for tanning leather among other uses. If they have leather in the house, chances are she’s been exposed to a little bit of it.
I’m not saying that these chemicals are good for anyone, but a bit of perspective would come in handy when trying to demonise an entire industry.
[12.44] he mentions a likelihood of illnesses that might be linked to the industry activities. No references given, no corroborating evidence.
[13.00] When talking about the breast cancer rates of Denton County in Texas skyrocketing, Fox is only partially telling the truth. From 1975 to 1999, breast cancer rates went up from 103 instances of cancer per 100,000 people to 141 instances of cancer per 100,000 people. However, from 1999 to 2008, the rate of cancer has dropped according to the National Cancer Institute statistics (http://seer.cancer.gov/data/). If the rate of gas drilling and production has increased over the past decade, shouldn’t there be a much larger correlation between cancer rates and the rate of gas production?
Medical trends such as cancer occurrences in particular areas have a very large amount of factors that go into it, so it will take more than a simple dot to dot connection of increased drilling and increased breast cancer to come to a scientifically viable conclusion of the relationship.
[14.42] The interview with Assemblyman Robert Sweeney is also a very well known tactic of trying to sully the current reputation of an industry by bringing up past transgressions. Yes, the oil industry has not been entirely truthful at times, and it deserves to be scrutinised and held accountable for the mistakes, and blatant abuses of power, however the past does not always predict the future. At 15.09 when he says “sticking the tax payers with the cost” I think that he also forgets how much tax revenue a set of oil rigs brings a county, not to mention jobs.
North Dakota received over $398 million dollars in tax money from oil companies drilling within their state in 2008 which was the second highest contribution of taxes into the state treasury http://www.nd.gov/ndic/ogrp/info/g-015-033-faq.pdf.
[15.40] Saying that no one would know about the fracking within the state had there not been “people talk(ing) about this” that everything would have gone the way of the oil industry and they would have polluted without repercussions is not only baseless speculation, but it doesn’t even make sense. There are a host of regulations that are imposed upon oil companies when entering a state for drilling such as seen here http://www.velaw.com/uploadedFiles/VEsite/Resources/UnitedStates.pdf.
[16.28] Again, baseless accusations and speculation based upon no supporting data. Just because permits are given for 5 counties does not automatically mean that oil companies will immediately, or even gradually, take over all surrounding areas until they blanket the entire State.
[16.38] When Fox states that there is no plan for wastewater disposal and no plans for a health impact survey, please note the above link about oil and gas drilling regulations. There is a very large set of rules and regulations that oil companies must abide by.
[17.02] “They don’t want you to know that Tom Ridge was paid $900,000 to serve as chief spokes person of the Marcellus Shale Coalition.” The idea that they ‘don’t want you to know’ is a fallacy, as this information can be found here: http://www.pennlive.com/editorials/index.ssf/2010/08/tom_ridges_integrity_at_stake.html. Or how we’re not supposed to know about Tom Corbett. Unless you look it up http://articles.philly.com/2010-10-19/news/24982706_1_gas-industry-tom-corbett-campaign-donations.
Just like the papers that the oil industry was supposedly hiding that you can find with a quick Google search, you can find these contributions that the oil industry ‘doesn’t want you to know about’. This is a very classic case of spreading propaganda, conspiracy theorism, and sensationalism to sell your particular brand of dogma.
Finally at the end of the movie we get into some statistics about the amount of wells that will be leaking. If we look at the 20% figure will be leaking that Fox puts out, we find that if we look at the background data, we find nothing of the sort.
Lets take a look at some findings in an August 2011 report by the Ground Water Protection Council (http://fracfocus.org/sites/default/files/publications/state_oil__gas_agency_groundwater_investigations_optimized.pdf), more than 220,000 oil and gas wells were drilled within Texas and Ohio over the past 25 years, 16,000 of such were from the deeper shale horizons that produce the thermogenic gas (thermogenic gas is produced in deeper areas with more heat, biogenic gas is produced in shallower areas with less heat and more biologic activity). If we take the 20% failure rate that Fox touts, then we should see thousands of wells leaking right? But, if we go back to that report by the GWPC, they show that of the 34,000 wells that were drilled in Ohio over the years of 1983 to 2007, 184 incidents were recorded in all categories of failures. Of these 184 failures, only 12 were related to the casing and cement. This represents a failure rate of 0.03%.
“Who would you trust with our future, paid industry spokes people, or the people bringing to light the very documents the gas industry is trying to hide?” This final statement from Fox is ironic in so many ways. The documents are not hidden, you just have to search for them, like any other piece of scientific data. If we were to trust the ‘people bringing to light the very documents…” of any industry or event, then we would have to call into question the moon landings, the JFK assassination, medicine, all branches of science, and most scientific articles and findings. At some point, it just becomes ridiculous.
To conclude, this documentary does very little to raise to light the legitimate concerns and the technological and engineering difficulties that are involved in creating gas wells, fracking, and extracting gas from them. The documentary serves to use half-truths and lies to further a divide between the citizens of fracking areas and the companies doing the fracking. With a more civil and objective viewpoint from both sides, it is possible to come to an understanding and a plan of solving the economic, industrial, political, and scientific issues and difficulties surrounding hydraulic fracturing. This is true for every other energy producing industry on the world. An example of environmental impacts in an apparently benign technology is the possible impact in the manufacturing process of solar panels, or geothermal contamination issues, so even an industry on the surface of it that appears environmentally friendly needs objective study for health and environmental impacts. With greater communication between industry and the community, it is possible to live, and understand, in greater transparency and prosperity.
So, now we know where the organic material for petroleum come from, we know how it’s converted from it’s original state to a liquid/gas state, we know how it migrates out of the source rock and through other lithologies, now we need to know where it ends up, and how do we get it out. This section will also go into some of the controversies and massive misconceptions about oil drilling, hydrofracking, and contaminations of groundwater. First, let’s get to the science of the whole thing:
In the previous chapter, we explored the concept of a moving mass of petroleum, whether it be liquid or gaseous in character, through different rocks because of the differences in buoyancy in relation to water. So, we now need to understand how and where this petroleum is trapped. First, lets start with a major misconception that a lot of people seemingly have about oil reservoirs: It is not, again, not a big pool of oil in the ground. The oil and gas are trapped within the matrix porosity, or, to say another way, the spaces in between the grains of the material that makes up the rock that it is trapped in. Let’s make an easy example:
We all remember those ball-pits from when you were a child right (figure 1)? The huge padded pits full of multi-colored balls that are absolutely hilarious until you come across a section of wet ones which subsequently sends you into a fury of panicked activity trying to find the nearest exit and shower.
Figure 1: Despite popular belief, these are not public toilets for children.
Imagine if those balls had a piece of glass placed on the top of the whole pit (to make sure none float away) and then start pumping oil into the pit. You might want to take the children out first. Or not, doesn’t really affect the outcome of this experiment. Anyway, you’ll noticed that the oil only occupies the space between the balls. This is exactly what happens in an oil reservoir: imagine the plastic balls as quartz grains in a well-sorted mature sandstone with a porosity of about 30% (it’s a high number I know, but for example sake, we’ll take a Navajo sandstone porosity) and the oil is, well, oil. Now, you might be thinking to yourself, “but Cameron, sand is much smaller than those awesome balls, how can any liquid pass through a rock? It’s impossible!” Well, dear reader, I assure you, that you can have a liquid pass through a rock. You just need geologic time scales.
We can take an even more appropriate example: You’re at the beach drinking a beer (figure 2; because you’re a respectable geologist) and you are watching the waves come in and out. You’ll notice that the wave comes up to a certain point and then retreats back again, but you’ve also noticed that the water isn’t just sliding down the beach back into the ocean like if it were on glass, some of it disappears into the beach itself! Curious, you take a handful of that sand, and you press it with all of your might, and some water dribbles out. Having oil migrating, being stored, and then extracted through a sandstone is no different, it’s just it’s under more pressure and the grains are a bit closer together.
Figure 2: Beer for reference.
Let’s get into where the petroleum resides. There are many complexities upon these styles, but we will go into just the basics of it for now, and if you want to know more, let me know, and I’ll write a much more in-depth report.
First, there are many different elements to a hydrocarbon trap, namely a reservoir rock, top seal, lateral seals, bottom seals and a sympathetic structure for trapping (figure 3).
Figure 3: A- Structural traps describing the interplay between top, bottom, and lateral seals with reservoir rocks and hydrocarbon accumulations; B- same relationships depicted with a stratigraphic trap (Biddle and Wielchowsky, 1994).
In the above schematic from Biddle and Wielchowsky, 1994, we can see all of these elements in play with each other. In figure 3A, this is what is known as a structural trap, and in figure 3B, it is a stratigraphic trap. These are just two distinctions that are made in the petroleum industry to better describe and separate the different types of traps and is very important for describing the geologic setting that they occur in.
The structural trap in A has slightly dipping sandstone reservoirs (remember in the past chapter where I described that migration in a sandstone happens in a slightly dipping bed) and is sealed on one side by a fault, the top by a shale, and the bottom with a shale. The petroleum is now trapped.
What are these seals usually made of? Well, a seal is anything that doesn’t allow the hydrocarbons to pass through it, so it could be tight shales, salt, gypsum, a fault, or an unconformity (a boundary of erosion).
The same exact principal is in effect with stratigraphic traps. The only differences between a stratigraphic and structural trap is that the stratigraphic traps are not directly related to a structure such as a fault or anything fault created (such as anticlines).
Figure 4 depicts examples of structural traps from Biddle and Wielchowsky 1994.
Figure 4: Structural trap types and varieties (Biddle and Wielchowsky, 1994)
For comparison, here are some variations on stratigraphic traps (figure 5; Biddle and Wielchowsky, 1994)
Figure 5: Stratigraphic traps (Biddle and Wielchowsky 1994)
So, now we have all of the petroleum in one spot. How do we get it out? In part 2, we will talk about the main methods of oil and gas recovery, the good, the bad, the unfounded, and the conspiracies.
Biddle K.T., C. Wielchowsky 1994, Hydrocarbon Traps in Magoon, I,. B, and W.G. Dow, eds., 1994, The petroleum system – from source to trap: AAPG Memoir 60.
Traps and oil/gas production with commentary, Part I
Now that we have a basic understanding of how hydrocarbons (both liquid and gas) are formed from the original organic material, we need to figure out how it gets into a place that it is allowed to accumulate. This transport of the expelled hydrocarbons from inside the source rock to a ‘gathering place’ is known as migration.
There are a few things we need to consider when we are talking about migration of hydrocarbons to its final gathering place. Firstly, what kind of source rock is producing the hydrocarbons (silt, shale, sandy), what kind of overburden that are deposited on top of the source rock, the tilt of the basin, and, maybe most importantly, what kind of tectonic regime is the production in? In this post, I will address the migration within the source rock (primary) and then out of the source rock and into the overlying strata (secondary) and what factors are included in that. So, let’s get started
If you remember from the previous post about the conversion of kerogen into liquid or gaseous hydrocarbons, we have an organic rich sediment that is being pressure cooked to the point of hydrocarbon production.
Not all of the kerogens are converted to hydrocarbons, and the black material that is left over (hard to crack kerogens) is called coke. Because the kerogen may be load-bearing and is able to transmit stresses, as the transformation from solid kerogen to liquid petroleum occurs, the pore-fluid pressure increases, and the overall ability of the source rock to transmit stresses decreases. With the transformation from solid to liquid phases, the overall volume of the source rock increases very slightly, so now we’re left with a problem: We have a very non-porous shale, under massive compression, with little or no permeability, that is slightly increasing in volume from producing a more buoyant liquid that wants to travel upwards.
This leads to the main idea of primary migration and specifically a couple of ways to transport liquid hydrocarbons out of a source rock: There can be very thin layers of siltstones or sandstones within the source rock itself, thus leading to a lateral transport pathway, but this isn’t always the case. If there is a very non-porous source rock, there will come a time when the pore-fluid pressure becomes so large, that it will essentially hydraulically fracture itself. This leads to high permeability pathways (cracks) for hydrocarbons to travel.
Incidentally, this is exactly why there is a lot of ‘hydrofracking’ in the oil industry these days, where a horizontally drilled borehole is drilled through a shale containing gas, and then water mixed with certain chemicals and some sand is pumped at tremendous pressure into the borehole, thus reaching this critical pressure and fracturing the shale, thus giving the shale forced permeability pathways for hydrocarbons to travel along.
So, now we’ve gotten the hydrocarbons out of the source rock. Hurray! Now what?
Now we have secondary migration. If you want to know more in depth about this, please let me know because there are a lot of complexities to secondary migration, but I will make it simple for now.
Secondary migration is basically buoyancy driven movement along, and sometimes through, different overlying strata until it becomes trapped in a place that it can no longer pass through. Usually, hydrocarbons will migrate along the tops of dipping sandstone beds (the top because it will percolate through the sandstone until it gets to a less-porous interface). Migration through sandstones has a huge amount of complexities due to the depositional environments, types of structures, and tectonic influences. If the basin is full of shales above the source rock, then it will need to find pathways either through structures, or from forced permeability via fracturing.
Although, sometimes, hydrocarbons can’t get through a certain layers such as salt, gypsum, shales, and other very non-porous and competent rocks. This is what is known as a top seal, but we’ll get into that a little later.
In the next post, I will explain where hydrocarbons get trapped, why they get trapped there, and how to think in 3D when dealing with migrations into these traps.
Now, this is probably a question that many people don’t really ask, but it’s an important one as I see a lot of students, and even some professionals struggling with this: How do I read an article?
It is so easy to start a new project, sit down, get some articles, start reading, and then completely forget what you’ve read the instant you put the article in a drawer because you either didn’t know why you were really reading this, what the end-goal was of the article, or how to integrate it into your project. Here, I’ll explain my method of reading articles and how you can save yourself a lot of time and frustrating alcohol consumption when it comes time to write your reports.
In each article, there will be 3 different types of information that you will want to retain: important information that pertains to the article subject matter, extremely important parameters or ideas that pertain to the article subject matter, and important ideas that pertain to geology as a whole. For these, I use different colors of highlighter: green and yellow for the important information pertaining to the article (so that there is some delineation between different ideas), orange for extremely important parameters for the article, and pink for the overall geologic information. This way, when I flip through the paper when I am writing, my eyes know exactly where to go and what I’m looking at. It helps also to put notes next to important ideas so when you are in the process of writing an article or report, you don’t have to spend a lot of time trying to figure out why you highlighted something.
If there is an important reference, I’ll usually color those in blue and number them, both where they are referenced to in the text, and a corresponding number in the bibliography.
Afterwards, if I am starting a new project or a new type of geologic setting, I’ll write maybe a page synopsis of what went on in the article, and I’ll interject my own opinions, questions, and ideas throughout. This way I know my thought process and it’s absolutely amazing what ideas you have when you are reading an article that you will later completely forget about. The other important reason that you want to keep a log of what you’ve read, your ideas, and what you were thinking as you were reading is that when it comes time to write a 500 page report, you can almost just rearrange what you’ve written, figure out answers to the questions you’ve listed while you’ve been reading the articles, and you’ve got the skeleton of your report already done, with little extra work on your part.
So, keep it logical, run the flow charts, keep organized, and keep a system. It’s a lot of work in the meantime, but trust me, when it comes to write and you’ve read 300 articles, you’ll thank yourself a million times over.
Literature research and synthesis is an extremely important component of successfully completing a geologic project, especially if you are in academic research. However, literature research can leave you feeling lost, confused, frustrated and hopeless. What do I search for? How do I know what is right and what isn’t? I have a stack of papers that I’ve read, so. . . what do I do with the knowledge I have now? How do I organize them? And, most importantly, how do I utilize the information and integrate it into my current database and interpretations?
Let’s work our way through an example project and try to understand what you will try to look for when doing literature research.
For this example, we will try to understand the correlation between graben width and depth to moho, with a case study from the Basin andRangeProvincein theWestern United States.
So, let’s take the question, break it up into components, and try to understand what we are even trying to answer. All you want to really do is have a piece of paper, and make a flowchart, or some sort of organizational scheme that will allow you to follow your own train of thought. My train of thought for this question would be as follows:
I have horsts and grabens which I can see from seismic images and the geologic map, so I need to know extensional tectonics and how it relates to depth to Moho. To understand that relationship, I need to know the mechanics of normal faulting and how each type (listric, planar, low angle, high angle) will affect the β factor (amount of crustal thinning). I will also need to determine the depth to moho from geophysical maps, so how does crustal thinning appear on gravity and magnetic maps? If I am going to be doing further research, then it would be prudent to understand the relationship of other external factors and the depth to Moho, such as the temperature, location, and mineral contents of geothermal wells.
Basically, you want to follow the chain of logic. If I have an oblique-passive margin, I need to read up on how the mechanics of the faulting work, how sedimentary systems are going to react in both pure extensional and transverse environments so that I understand the end-members, so when there is a case of a mixed setting, I will be able to distinguish between what is extension driven and what isn’t. It is also important to understand how the faults react to different lithologies, temperature regimes, and heat flow domains to understand the shape of the fault, if it will be a ‘leaky’ transform, or if it will be purely a brittle phenomena.
Follow the logic, make a chart, write everything down. It helps tremendously.
Whenever you log onto a news website, there is inevitably an argument by some politician, social group, or just normal people about how petroleum is ruining/running/destroying the world (especially when it comes to fracking). When you start to read their comments and arguments, as a geologist you start to see an extremely disturbing trend: probably 95% of the people that are complaining about petroleum, how it is extracted and how it runs the world have no idea how petroleum is found, formed, and processed.
I know it’s probably not the most important part of the debate in the aspect of world economics, but it should be a requirement to understand the basics of petroleum systems before you try to regulate the oil industry.
I don’t care much about the economic impacts, so what we will do over the course of the next few days is describe, slightly above laymen levels, the basics of petroleum systems, and at the end we will have a guest scientist explain how petroleum is refined. Lets get started:
A petroleum accumulation is the result of a number of processes and a massive amount of time. Basically it comes down to this: You have a source rock that is usually a black shale (meaning that there is a large organic carbon contribution to a shale bed), it is cooked, petroleum is released, the petroleum travels to another place (because it is more buoyant), and it gets stuck somewhere until someone drills a hole and pumps it out.
Let’s talk about what may arguably be one of the most important factors: The source rock.
Most of the organic carbon comes from algae (although people always love to say “you’re burning dinosaurs, but that’s just not correct), but there can also be contributions from terrestrial plants (such as trees, leaves, seeds, etc.). One problem that we immediately see, is that if the organic matter rots, or oxidizes, it can no longer be considered useful for petroleum generation as the porphyrins are extremely reactive with oxygen. Therefore, the organic carbon needs to be deposited in an anoxic environment, such as deep seas or sometimes very large deep lakes, or it needs to be buried in a place that has an extremely large sedimentation rate, so that the organic carbon gets buried and compacted faster than it can be oxidized.
Once this organic material is buried to a sufficient depth, the organic material begins to decompose and degrade (please note that ‘decompose and degrade ’ in this context does not mean rotting, or oxidation!), and partially separates into its constituent parts, namely biopolymers from proteins and carbohydrates. These constituent parts begin to form new polymers named geopolymers. Given enough time, pressure, and temperature, these geopolymers create a substance named kerogen which is composed mainly of carbon, hydrogen, oxygen, nitrogen and sulfur.
The type of kerogen depends on the type of organic material that went into making it. Please note that kerogen is not a chemical compound, but more of a mixture of organic material, so the precursor material is extremely important to understand when trying to understand the type of kerogen that will be formed, and subsequently what kind of petroleum is formed.
Types of kerogens:
- Type I: (Sapropelic) This type comes from the deposition of lacustrine algae in anoxic conditions. Because algae has a very large percentage of lipids (in comparison to terrestrial plants), it has been show to have a great affinity to form liquid hydrocarbons such as crude oil.
- Type II: This type contains more oxygen than type 1 and tends to produce a mixture of gas and oil. It is mainly created from Plankton in marine settings. Unlike in type I kerogens, the organic material is deposited in a reduced environment instead of purely anoxic (although, there are currently arguments that state there is no such thing as purely anoxic conditions, just massively reduced). Type II-S is just like Type II, just with an increased sulfur content
- Type III: (Humic) Terrestrial plants compose most of this category which includes wood, leaves, and other fibrous material from land. This material produces coal and gas as it lacks the necessary amount of hydrogen to form hydrocarbon chains. This is not to say that type III is not capable of creating liquid hydrocarbons, it is just exceedingly rare and only occurs under very specific conditions. Terrestrial plants have the lowest concentrations of lipids of all the precursor kerogen types.
Figure: Modified Van Krevelen diagram which displays the primary composition of the differing types of kerogens and the levels of maturity with associated hydrocarbon types.
Now that we have the organic carbon buried and starting to rearrange into kerogen types based upon their precursor organic carbon type, we need to pressure cook the material to obtain the hydrocarbons from the ‘cracking’ of kerogens.
This increase in temperature from burial (the rate of temperature increase in a ‘normal’ basin is around 30°C per kilometer, but in basins where there is extension, it can be more around 40°C per kilometer) will begin to break the chemical bonds of the kerogen and produces smaller molecules which compose oil and gas. The main window for this breaking of kerogen into smaller molecules requires a temperature around 80-150°C and on a time scale of 1-100 million years (although this number has been fluctuating and narrowing quite a lot in recent times due to the increasing types of methods to determine the production of hydrocarbons).
There are many ‘windows’ of temperature ranges that will produce differing types of hydrocarbons, such as seen in the Van Krevelen diagram. The oil window is typically from 100-150°C which corresponds to around 3-4 kilometers of depth. Note that the temperature can be altered by a raised geothermal gradient that can be due to an upwelling of the asthenosphere, proximity to plutons or volcanic activity, or the amount of radioactive material within the under/overburden or it can be lowered by being located in a colder craton such as a shield. Anything above this temperature will produce gas, or if raised for extended periods of time, the kerogen composition will be gradually depleted until there is a pure carbon residue left over (graphite).
The rate of petroleum generation follows the Arrhenius function:
; where R is the gas constant, T is the temperature, and Ei is the activation energy. Ei varies between 50 and 80 kcal/mol or approximately 200 kJ/mol. A is an exponential constant that is dependant on the type of kerogen (I,II,II-S, III).
Because the temperature is going to be fluctuating through time as burial progresses, if you have uplift, or changes in geothermal gradients, the effect of temperature is required to be integrated over the range of temperatures. This is called the TTI, or Time Temperature Index
; where (T) is the integrated temperature over time from deposition time (t0) to the present day (tx). F represents a factor that is dependent on the activation energy (Ei) for the reactions. Based upon this calculation, we can conclude that the rate of the reaction approximately doubles for each 10°C increase of temperature.
If we wanted to understand the maturity of the source rock at any given time and with the already calculated and known inputs, we can create a theoretical maturity parameter (P) in which temperature is integrated with respect to time (t):
Information and associated references taken from Bjørlykke, 2010
So, it turns out that there isn’t really a good geoscience blog on the internet (surprisingly). So, what will happen with this blog is that we will have visiting scientists coming in and posting about their areas of expertise along with regular posters from different disciplines in the geosciences speaking about their work, methods, and results along with interacting directly with everyone that will read this blog. As of this point, we will have 4 people contributing with a lot more expressing interest in helping.
If there are any geoscientists that are reading this and are interested in contributing to this blog (even if it is one post about what you do as a job every day) it would be absolutely welcome and it would be extremely useful. Just let me know!
I’m always amazed at how geology is portrayed in the media, particularly within the movies. There will be some natural disaster, and you’ll cue to some geologist with a huge computer that is displaying a colorful model that rotates around while he describes why a man-made machine is causing the Earth to stop rotating, or some stupid premise like that.
Either that, or the geologist is seen as a guy (or gal) out in the desert, wearing clothes that a homeless person would be embarrassed to be seen in, all the while whacking rocks with a hammer and looking at the small shards with a loupe exclaiming ” Well, sure, it’s a hornblendite, and that means in this area a massive supervolcano will create a carbonate platform where we’ll start to find dinosaur bones embedded in pure peridotite”, which makes about as much sense as finding a massive geode in the mantle. But, we won’t get into that right now.
These two examples above are basically end-members. Lets take a look at a breakdown of how a project goes from some person in the field looking at rocks, to having a beautiful 3- or 4-D model. It is important to note that I have made this intentionally jargony and fairly technical because I want you to have questions which you can put into the comments and we can start discussions in a later thread that I will dedicate to your question.
First, we have to gather data:
Yes, I know it’s a shock to a lot of people, but geology is really a science. No, really, it is! The first step to any scientific endeavor (or at least an honest one) is data-gathering. There are many types of data that are necessary for a large comprehensive project, such as:
- Surface Geology and geomorphology: This is where a true geologist is at his most comfortable. Out in the field, no one in sight, nothing but beer and half rancid ham-and-cheese sandwiches that are compressed into a ball from rattling around in the bottom of their pack all day. The surface geology gives an idea of what processes created the particular area in which you are in. This is a very VERY important portion of the geologic data gathering process as it is basically a story book of what went on. The problem is that it’s only the last chapter. So, based upon the characters, how they talk to each other, where they are, what they’re wearing and what language they are speaking, you are supposed to recreate the first chapters. That, my friends, is why geology is so fantastic. It’s the ultimate puzzle.
- Seismic reflection/refraction data: which is basically a cross-section of the Earth based upon impedence values of the rocks. These can be extremely big, as an example of a project we were working on, the largest line was around 500 kilometers in length, and about 12 kilometers in depth. Seismic data is input and interpreted in either Petrel or Kingdom Suite (or SeisWorks or Landmark, just depends on which package your company uses)
- Well data and petrophysical data: This includes gamma ray (radioactive decay), porosity, electrical conductivity, temperature, sonic, and other pieces of information that can be gotten from the rocks through a 4 or 9 inch hole that can be upwards of 5000 meters deep.
- Geophysical data: These are things like magnetic maps and gravity maps, each of which have many mathematical derivatives and each highlight different features in an area.
- Geochemistry: Anything pertaining to groundwater isotopes, chemical signatures in wet or dry petroleum, bulk chemistry of geothermal vents, rock geochemistries, and even AFTA and ZFTA timing and dating.
- Literature: One of the main things that never gets glorified, or even mentioned when the media has an interview with a scientist of any discipline, is the absolute massive amount of reading that goes into a project. It is possible, for a longer term project over a few years, to read upwards of 400 articles and many books. I have personally read through my textbooks that I had in university, cover to cover at least twice (which is ironic because I never read them when I was in my undergrad). Thousands of pages need to be read to become proficient in an area. Coincidentally, this is why a lot of scientists get extremely annoyed at people that come to them with their pet projects or ideas (this mainly happens in physics) when they haven’t read the first bit of literature.
Now that we have the basic information, we start to compile this information in ways that are logical to reach our goals. These goals depend completely on funding and what information is available (very rarely do you have all of the aforementioned datasets available for your usage). But, for the sake of this post, because it is meant to inspire questions, lets just do a whole basin analysis.
The first thing we will do is interpret the seismic profiles to get an idea of the main unconformities and structures. The major unconformities are mapped and are called horizons. These horizons are then mapped around the seismic grid and subsequently become large layers, basically a topographic map of that particular time period. If we subtract one topographic map from another either on top or below, it will create a thickness map. This sedimentary thickness map tells a very very important story and can be the backbone of your interpretations.
The main structures are then interpreted, so you could have faults, mountains, valleys, huge canyons, anything. Once they are mapped, you will have a good model of the structure trends.
Now, most people think this is where this part of the process stops. You already have a 3D model of the entire basin, so why go further? The problem is you have to understand why it is that way. Why is there a break in normal faults there? Why is the basin deeper here and not there? Why a mountain, why not a valley? When we get to the chapter of structural geology, we will answer all of these questions.
Now that you have an explanation for the way that the basin is, we want to start characterizing the layers that we’ve created. A thickness map is fairly useless on it’s own, so we have to take all of the information we had before and populate the thickness map with data. This data comes from the field geology, well and petrophysical data, geophysics, geochemistry, and literature. So, everything described above. All of this information is then compiled, displayed, and interpreted within ArcGIS
Once all of the data has been input into the model, we need to understand how radioactivity and the mantle upwelling have played a role in the thermal evolution of the basin. So, if we have any organic rich shale that has a type I kerogen, are we going to reach a Tmax great enough for expulsion, or are we going to have something that is overheated and we’ve turned everything into graphite? If there is expulsion of hydrocarbons from the cracked kerogens, where is it going to go? Where will it stay? How long will it stay there? How do we get to it? And, most importantly, how do we find it?
There are a million different complexities that go into trying to find petroleum and even to come up with a nice, colorful, rotating picture on a computer screen. What I will try to do through the medium of this blog is to take you, step by step into each of the areas I’ve described above and help you understand the Earth on which you live and how we find the fuels that rocket us along.
Living in the Shadow of Mountains. 