When the World Trade Center was being built in 1973, Dr. Irving Selikoff, an expert on asbestosis and cancers caused by asbestos, was an outspoken critic of the wholesale spraying of the floors of the two structures with insulator containing copious quantities of asbestos for fire-proofing. He knew the potential dangerous hazards of asbestos as did the asbestos industry. Fortunately not all floors were insulated because New York City instituted a ban on the spraying of asbestos in the same year. Fast forward almost 30 years when the plumes of dust rolled over lower Manhattan after the collapse of the World Trade Center towers on 9/11. The brave souls that rushed to help survivors and participate in the cleanup along with the many people that lived and worked in the area were exposed to one of the most serious carcinogens ever documented – asbestos in its many forms. One of the most deadly results of inhaling the tiny asbestos fibers that permeated the World Trade Center clouds is the nearly always fatal cancer mesothelioma (known to be caused only by asbestos). Unfortunately, the cancer often shows up decades after exposure. What many people do not realize is that asbestos has still not been banned in the United States even though the asbestos community has known internally since at least the 1930s that it was not only harmful but deadly. The asbestos executives and their hired doctors promulgated a disinformation campaign that asbestos was and is harmless knowing full well that these claims were patently wrong1.
Selikoff first came to prominence in 1964 when he organized an international symposium on the “Biological Effects of Asbestos” through the New York Academy of Sciences. Selikoff, through his position as the director of the Environmental Sciences Laboratory at the Mount Sinai Hospital in New York, was able to persuade the International Association of Heat and Frost Insulators & Asbestos Workers union to provide him with workers’ medical profiles2. He presented four papers at the conference on the results of his epidemiological studies of the union workers. There was no mistaking his results — working with asbestos insulation caused an increase in death by 25 percent from not only mesothelioma but asbestosis, lung cancer and even cancers of the stomach, colon and rectum. His independent research could not be buried by the asbestos industry as they had with their subsidized research, and Selikoff’s results were reported widely in the press. Selikoff’s team even found that insulator workers who smoked were ninety times more likely to get some form of asbestos-related cancer than those workers that did not smoke.
I don’t want to appear sanctimonious, but the dangers due to asbestos Selikoff and others reported in 1964 should have caused the asbestos industry pause – maybe even force them to attempt to improve working conditions. But as in other industries with similar threats, the asbestos executives circled the wagons and then went on the offensive. The Asbestos Textile Institute’s lawyers (the asbsetos industry’s public relation’s arm to promote asbestos products) sent letters to the New York Academy of Sciences and Selikoff warning them about the impact of their “damaging and misleading news stories”. Their smear campaigns began by attacking Selikoff’s medical credentials and the quality of his work. For years, the asbestos industry stalked Selikoff and others at conferences and meetings attempting to undermine their work. More details can be found in Jock McCulloch and Geoffrey Tweedle’s outstanding book entitled Defending the Indefensible: The Global Asbestos Industry and its Fight for Survival.
It is astounding the lengths the asbestos industry went to suppress information they deemed adverse and to circulate disinformation cranked out by their hired doctors and researchers. Asbestos executives also turned to the largest public relations firm in the world – Hill & Knowlton – a sort of hit squad of lawyers with a ubiquitous presence in undermining science damaging to their clients which included Big Tobacco3. But perhaps what can only be described as turpitude, the companies led the disinformation campaigns while laborers in a whole slew of industries from mining to textiles worked in deplorable conditions that caused sickness and death. In the Libby mine in Montana, for example, not only was fibrous asbestos dust so thick in some areas of the open-pit mine it was hard for workers to see each other. The dust blew into the nearby town causing asbestos illness and death to residents (the Libby mine was eventually closed due to the huge number of tort claims by families struck by illness and death related to the operations). It was common for the industry to fire workers that developed asbestosis or cancer to avoid the appearance of illnesses related to asbestos. When it became clear to the industry that mesothelioma was a serious public relations nightmare, their public relation’s machine went into full overdrive focusing on two strategies. 1) Reassuring people that asbestos-related diseases were caused only by the inhalation of large amounts of fiber dust over long periods of time (internal memorandums clearly show that the companies involved knew this was not true). 2) Foisting the argument on the public that mesothelioma was the result of blue asbestos and that other types of asbestos, such as chrysotile, were safe (once again, internal memorandums show that the companies knew this to be patently untrue).
The diagram below shows the world production numbers for asbestos from 1900 through 2015. One might think that the asbestos industry would have been crippled by Selikopf’s research reported in 1964. But production actually increased through the 1960s and went on increasing into the late 1970s before tort claims began to impact the industry. But even today, worldwide production has not decreased below the early 1960s output due mostly to production in developing nations. The diagram is a testimonial to the success of the asbestos industry’s ability to undermine solid scientific research with political clout and the financial resources to promote their agenda – asbestos is safe. We have seen the same thing in many other industries like Big Tobacco with smoking and Exxon with global warming. McCulloch and Tweedle make a salient point: “Put another way, nearly 80 per cent [sic] of world asbestos production in the twentieth century was produced after the world learned that asbestos could cause mesothelioma!”
Data from Virta4 for 1900 through 2003, Virta for 2004 through 2006 (consumption), and Statista for 2007 through 2015.
Imagine that you are the mayor of a small town dependent on tourism, and doctors in the village are reporting an outbreak of a bacterial disease that is killing 40 percent of those being infected. You decide that reporting the disease to the CDC or WHO would harm the financial health of your town and you seek to suppress the seriousness of the outbreak. You tell tourists they have nothing to worry about and chastise the local news affiliates by telling them they are acting hysterically and causing undue panic. Would anyone deny that you are guilty of a serious criminal act? This is essentially what the asbestos industry did over many decades, and yet no one in the asbestos industry has served a day jail time for their actions. In fact, they were so successful in their disinformation campaign that even today as mentioned above asbestos is not banned in the US even though cheap substitutes exist and asbestos has been banned in other industrial nations such as France and Britain. I asked Dr. Jock McCulloch why and his response is telling: “There is no easy answer to your question nor to the adjacent one as to why 2 million tons of asbestos will be mined and used globally during 2016. One of the key factors has been the corporate corruption of the science (which began in the 1930s) and the other is the baleful behaviour of Canada at international forums- due in the main to federal/Quebec politics. And then there is Russia, its political climate and anti-western reflexes.” Both Canada and Russia have been and are huge producers of asbestos and Canada with the help of scientists at McGill University funded by the asbestos industry (one of the reasons why scientists should remain independent in their research) has been instrumental in persuading other governments to act gingerly against asbestos interests.
Distressing research now shows that trivial exposure to asbestos can cause cancers. The Harvard paleontologist Stephen Jay Gould died of cancer caused by asbestos fibers perhaps from asbestos within ceiling tiles. Actor Steve McQueen died at the age 50 from mesothelioma probably from asbestos exposure when he worked in a break repair shop (breaks are lined with asbestos). Many instances of cancer among family members of miners and other laborers in the asbestos industry have been attributed to exposure to asbestos fibers brought home on clothing. I think about the lives destroyed by asbestos when I read the words of McCulloch and Tweedle: “Central to the strategy was a policy of concealment and, at times, misinformation that often amounted to a conspiracy to continue selling asbestos fibre irrespective of the health risks.” I might add that attempts to force the asbestos industry to warn their workers about the dangers of asbestos were averted. And although most mining and manufacturing has moved out of industrialized nations, the developing world has picked up the slack — places like Swaziland where laborers have few protections and little legal recourse for compensation from asbestos illnesses. Records through litigation have turned up showing that industry officials thought black workers were far less sophisticated than those in the US or Europe about hazards to their health and sought to take advantage of them.
Stephen Jay Gould 
Steve McQueen
Sadly, the large asbestos companies (18 in all) were able to avoid paying thousands of tort claims in the US by declaring bankruptcy through Chapter 11. Bankruptcy implies that a company is insolvent, but due to the Manville Amendment passed by Congress in 1994 to help the asbestos industry, companies only need to show that future liabilities exceed the assets of the company in order to declare bankruptcy. The insurance companies pulled a similar “fast one” by shuttling liabilities into shell companies that also declared bankruptcy. I am very much for free and open trade but companies should be held responsible for travesties, and the bankruptcy claims are tantamount to highway robbery in my humble opinion. Many of those who lost out on benefits and claims were already on the edge of poverty from unemployment and the medical costs from their ailments. I might also point out that the American taxpayer is the ultimate source of support to these workers and their families because the asbestos companies were able to weasel their way out of their responsibilities to their employees and/or those harmed by their products. It may be important to remind the reader that it is estimated that between 15 to 35 million homes contain Libby asbestos as insulation. Asbestos is a problem that is not going away quickly.
I understand that industries like asbestos employ a large number of people (at one time in the 1960s, more than 200,000 people worked in the asbestos industry) and many of these workers would have difficulties finding new jobs elsewhere if the industries were closed overnight. But there are various steps that should be taken based on what we have learned from the asbestos travesty when future industries are found to be responsible for harm to their workers. 1) It should be a crime to purposely mislead the public and/or workers on safety issues of products. This must include the purposeful undermining of peer-reviewed science. The penalties should be stiff and include jail time. Laws need to be enacted accordingly. 2) Workers and their families need to be informed of the dangers in clear language in order that they may decide whether they wish to take the risk of continued employment in the industry. 3) In cases like asbestos where it is clearly a dangerous hazard, the product should be phased out by substitution of other products and eventually banned. 4) Workers and those impacted by the product should be entitled to compensatory damages through the establishment of funds in negotiations with the government. 5) And finally, American companies should be prohibited from moving their operations to nations that have lax laws that permit workers to be exposed to the hazardous products. If corporate America can’t police itself (and I don’t think they can based on the tales of woe involving tobacco, pesticides, global warming, etc.) the government must step in.
- McCulloch, J. and Tweedale, G. (2008) Defending the Indefensible: The Global Asbestos Industry and its Fight for Survival: Oxford University Press ↩
- Selikoff recruited Dr. E. Cuyler Hammond who had already published his landmark research on the link between smoking and lung cancer ↩
- Oreskes, N. and Conway, E. M. (2010) Merchants of Doubt: Bloomsbury Press ↩
- Virta, R. L. (2006) Worldwide Asbestos Supply and Consumption Trends from 1900 through 2003: USGS Circular 1298 ↩
The term fracking conjures up so many knee-jerk-bad reactions that I am hesitant to broach the subject. I suppose if I am going to wade into the topic I should give some bona fides to display my knowledge of the petroleum industry, but not too many bona fides so that I might be seen as a talking wonk for the gas industry. I worked for one year as an engineer for a well service company called Schlumberger (world’s largest) and two as a geologist with Shell Oil. Shell gave its geologists full responsibility for drilling a well from the time it was proposed to production if it hit oil. Of the 11 wells I proposed, 3 hit oil which was above the industry standard in producing fields in the late 1970s and early 1980s. Eventually I realized my calling was in teaching and research and left to go back to school for my PhD. But not before I got a pretty good idea of how the industry works.
The process of drilling is not complicated although the devil can be in the details. A rig contains strings of thirty-foot drill pipe which attach to a tri-cone tungsten carbide bit (see the image below). The bit spins from drives or motors as drilling fluid, called mud (contents vary but clay, water and lubricants are typical), is pumped through the pipe string to keep the bit cool, increase pressure, and bring the rock debris from drilling back to the surface along the outside of the pipe. One of the technological marvels developed in modern times is the ability to direct the drill bit to specific locations with pin-point accuracy by knowing where the bit is in three-dimensional space usually thousands of feet below the surface. Directional survey measurements are complex but are based on measurements while drilling through various instruments. These advances have enabled horizontal drilling which has become important in fracking.
Rama, Wikipedia
I would be remiss not to emphasize the importance given to protecting the water table when drilling. State and Federal regulations require the well to be sealed off at least 50 feet below where potable groundwater can be produced, and those laws have been in place as far back as anyone can remember. The drill pipe is tripped (pulled completely out of the hole) when regulators deem the surface casing should be set to protect the water table (something on the order of 500 feet usually). The casing is cemented in place, and if it is done correctly, we know from the drilling of hundreds of thousands of wells over many decades that the water table is protected. After the surface casing is set, drilling is continued until the target zone is reached. The pipe is tripped again and the entire well is generally set with cemented production casing. The hole is plugged at the bottom usually up to 50 feet below the horizon of interest. The casing is perforated by tools that blow holes in it precisely where the rock containing oil and/or gas exists. Lisa Margonelli has written an excellent book entitled Oil On the Brain about the details of drilling and its impact on the politics of many countries like Nigeria and Venezuela1.
When I worked for Schlumberger, it was my job to determine if production casing should be set by running tools in the hole. The measurements produced records called well logs that gave us information about not only the rock below but whether it contained producible oil or not. Drilling is a chancy business, not for the faint of heart. Most wells never produce a drop of oil. I have seen many an owner of a wildcat well near tears as he realized from the logs that the well was a “duster”. That has changed to a great extent in the new-world order of gas and oil production through fracking. The new targets — usually oil shales — were discovered decades ago by previous drilling. They were ignored because shales do not naturally flow under the pressures at depth. Shale is very porous but not permeable. You need permeable rocks to produce oil and/or gas, or so it was thought.
That was before Mitchell Energy, a midsized exploration and production company, drilled the S. H. Griffin #4 well in North Texas into the oil- and gas-rich Barnett Shale in 1997. They used fracking techniques to produce large quantities of methane gas from what was traditionally seen as non-producible rock. If you are interested in more of the details, read Gary Sernovitz’s immensely entertaining and witty book The Green and the Black2. Sernovitz, even with ties to the petroleum industry, takes a rather neutral approach to adjudicate the brouhaha over fracking. One of the highlights of the book is his look at the impacts of the new United States gas and oil reserves on the political and economic scene.
The S. H. Griffin #4 not only produced gas, it produced it in steady quantities (1.5 million cubic feet per day). So how does fracking make an otherwise impermeable rock produce as if it was a well at the height of the oil boom of the 1960s in the United States? Fracking sounds ominous and sinister and conjures up visions of rock being fractured all the way to potable water zones. But it is nothing of the sort — pure fiction. The technique took decades of testing and experimentation in wells to develop. The secret is hydraulic pressure from fluids injected into the well to cause the shale to fracture. The fracturing is usually limited to about 300 feet in an outward radius around the drill hole. And don’t forget, the drill holes typically go down for thousands of feet below the surface and are protected with cemented casing that has only been perforated in small sections usually at the bottom of the hole where the target rock exists.
It did not take companies long after fracking became successful to incorporate horizontal drilling, another United States technological advance, into the new smorgasbord of production proficiencies. With the ability to target a bit within inches of a desired location, drillers learned how to gradually arc a pipe into the horizontal (see image below). The technology turned out to be a bonanza when combined with fracking. Companies drilled and set casing directly within and parallel to the oil shales enabling them to frack large sections of the rock which sent production through the ceiling.
EPA
The chemicals used in fracking were originally a trade secret, but people talk, and once the word was out, companies like Halliburton published the composition of their fracking liquids. Turns out 90 percent of the frack is made up of water, 9.5 percent consists of a proppant which is usually sand, and only 0.5 percent consists of the scary chemicals often used to undermine the industry. The sand serves as a support to keep the fractures (caused by the pressurized fluid) propped open so gas and/or oil will flow. I am not going to pull punches here. It takes a lot of water to frack a well. Sernovitz estimates that a typical frack (an average of 22 stages) uses between 4 and 8 million gallons of water and about 6 million pounds of sand. Unfortunately, not all of the fracking fluid stays in the hole. Some resurfaces. Today the water that comes back is reused or disposed of by pumping it into former producing fields in a concerted effort to make sure the chemicals within the water (even if they are only 0.5%) are placed out of harms way.
It has been widely reported that fracking causes earthquakes. Actually the disposal of water being pumped into the ground (usually from fracking) causes the seismic activity. Perhaps it seems like a trivial difference, but the public seems to have the idea that the pressure from fracking is so great that it directly causes earthquakes. The typical increase in seismic activity in a state like Oklahoma is usually effectively mitigated by diverting the injection of water from fields responsible for the activity or requiring the water to be disposed of via other methods. There can be little doubt that the earthquakes are associated with well injection and regulatory commissions need to fully address the problems.
The HBO premier of Gasland, a 2010 documentary about the natural-gas industry in general and fracking in particular, was probably responsible, at least in part, for New York State banning fracking and a great deal of misunderstanding about natural gas and its impact on the environment. I have two conflicting opinions about the documentary by Josh Fox. 1) It is clearly tarnished with misrepresented science, almost hysterical overreaction, and historical inaccuracies. The documentary has been thoroughly taken to task by Energy in Depth. 2) Having said that, there is no question that it is emotionally moving. It was difficult to watch people whose lives have been impacted badly by the failures of the gas industry. My conclusion — Gasland was necessary to open a national debate about the issue which has led to more government oversight and less rogue shortcuts leading to serious problems. However although there will always be problems associated with any industry, drilling for natural gas and/or oil on land in the United States is relatively safe to groundwater. We simply have to make sure that casing practices are properly implemented. Water taps catching fire in Dimock, Pennsylvania, happened because of sloppy cement work and poor casing in 27 holes during the early days of drilling in the State (gas leaked through the casing into the surrounding water table). I find it reprehensible that companies would not protect the water table at all costs and fully agree that the companies cited deserve the penalties they received and payouts they had to make to people they injured.
Finally, I need to emphasize that in 2015 the Environmental Protection Agency (EPA) did a summary paper entitled Assessment of the potential impacts of hydraulic fracturing for oil and gas on drinking water resources and concluded that “Assessment shows hydraulic fracturing activities have not led to widespread, systemic impacts to drinking water resources”. We can conclude that the gas industry has made mistakes, but we cannot contend that our drinking water is in danger because of fracking despite claims to the contrary in sources like Gasland.
Let’s not forget why Fox started filming the documentary – to protect his vacation home in a pristine part of Pennsylvania near the border with New York. I get it. No one wants a drill rig in their back yard even if it is only there for 40-days worth of drilling. By the way, if you want to read a reasoned and enlightening book about how people are affected adversely by drilling, I recommend Seamus McGraw’s The End of Country: Dispatches from the Frack Zone3. He weighs the potentially bad impacts of drilling with a healthy dose of understanding that gas and oil companies are filling a demand created by the United States and other world consumers. Unfortunately, Fox never examines the financial impacts of shutting down the fracking industry.
I recently wrote an article on the serious implications of global warming particularly related to the increase of athropogenic gases in our atmosphere. Of the three major fossil fuels, coal is, by far, the worst polluter of carbon dioxide followed by petroleum. Natural gas is the least (see figure below showing the effects of anthropogenic gases as radiative forcing). In fact, Sernovitz has emphasized that “the United States has led the world in carbon dioxide emissions reduction because of shale gas [use of methane gas instead of coal]”.
IPCC Fifth Assessment Report 2013
It would be unfair not to point out that methane leaks into the atmosphere directly from the production of methane gas contributing to anthropogenic gases (as methane) also, but according to the EPA in a report entitled Overview of Greenhouse Gases: “Methane (CH4) emissions in the United States decreased by 6% between 1990 and 2014.” During the period from 2007 to 2014, natural gas production was increased tenfold according to the US Energy Information Administration database. The EPA goes on to comment that “During this time period [1990 to 2014], emissions increased from sources associated with agricultural activities, while emissions decreased from sources associated with the exploration and production of natural gas and petroleum products.” Note the lack of effect from the natural gas boom between 2007 to 2014 in the graph below showing total United States methane emissions (converted to carbon dioxide equivalents). In a paper funded by the green-friendly Environmental Defense Fund (EDF) and published in the Proceedings of the National Academy of Science, Allen et. al4 estimated from measuring 190 onshore gas locations that about 0.42 percent of the methane produced leaks from drilling and completion of the wells. The EPA is working with the gas companies to further reduce this figure but, once again, it is hardly having the impact sources such as Gasland have portrayed.
The oil production in thousands of barrels per day since 1966 from the top ten oil producing countries (as of 2015) is shown in the diagram below. One of the most startling aspects of the graph is that the United States has become the World’s largest producer of oil. It’s not Saudia Arabia or Russia, it’s the United States. What is even more remarkable is that our world lead came through good old fashion American know how — the technology that enabled the United States’ producers to frack horizontally. I am no flag waver, but there is no denying how the United States has transformed itself. The halcyon days of the 1960s when the United States led production worldwide were thought to be gone forever (see figure). By the early 1980s, even secondary recovery processes in declining oil fields could not up American production. Our decline in oil production continued until about 2005 when fracking began to be felt. The dramatic impact of that technology can be seen by the subsequent rise in production for the last 10 years in the graph below. However, our increased production does not meet our ever-increasing demand, but it not only helps our trade deficit but decreases our dependence on oil from the troubled Middle East and a hostile Russia. Along with the increase in oil production, we have also become the world’s leader in the production of natural gas (don’t forget that both oil and natural gas have less impact on climate change than coal).
I asked Gary Sernovitz what he thought about America’s new role as a leading oil and natural gas producer: “One of the strange things about the gas boom is that even as prices have gone down, and activity has gone down (because of low prices), volumes have still gone up—a credit to how productive have been [sic] the wells in the Northeast US. This year [2016] gas production is down slightly, but we’re still producing 34% more than the Russians so no risk of losing our crown. 2015 was the year that we exceeded Saudi Arabia in total oil production, and became the world’s largest oil producer. We’ve temporarily lost that crown in 2016, but I’d expect [our] prices to recover for that leadership to happen again soon. And I do think we’re still by far the largest oil and gas producer, despite the dip in oil production because of prices, as we’re far ahead of Russia on oil now too.”
So I would like to summarize the article by stating categorically that we need to curb anthropogenic gasses (carbon dioxide, methane, etc.). But attempting to shut down the oil and gas industry in the United States because of fracking and/or to solve the climate change problem is like trying to take out a drug cartel to stop drug usage in the United States. The only way we are going to reduce our dependency on oil and gas is to reduce the increasing need for it. Fracking is relatively safe to the consumer and looks to be giving America another chance to remain less dependent on other suppliers while we find alternative sources to replace or at least curb America’s craving for energy.
- Margonelli, L. (2007) Oil on the Brian: Adventures from the Pump to the Pipeline: Doubleday ↩
- Sernovitz, G. (2016) The Green and the Black: The Complete Story of the Shale Revolution, the Fight over Fracking, and the Future Energy: St. Martin’s Press ↩
- McGraw, S. (2011) The End of Country: Dispatches from the Frack Zone: Random House ↩
- Allen, D. T. et. al (2013) Measurements of methane emissions at natural gas production sites in the United States: Proceedings of the Natl. Acad. Science: 110, 17768–17773 ↩
A few lucky souls have stumbled on diamonds in glacial debris around the Great Lakes and further north into Canada for centuries. Geologists have known that the sources of those diamonds represented a vast wealth of hidden treasure somewhere in the frozen tundra of northern Canada, but it was not until the late 1980s that a couple of cowboy geologists, Chuck Fipke and Stewart Blusson, painstakingly ferreted their way back to the source. But I am getting way ahead of the story.
Diamonds are brought to the surface from deep within the upper mantle via unusual igneous rocks called kimberlites (and sometimes lamproites). I recognize I run the risk of losing my readers by delving into the nature of kimberlites, but to a geologist like myself kimberlites are crazy types of rocks. Typical magmas (and lavas) like basalt form by partial melting of the mantle. Kimberlites, on the other hand, are geologically unique because although they form from partial melting of the mantle, the melting is significant enough for these rocks to resemble compositionally (not precisely) the mantle itself. They are referred to as ultramafic rocks as compared with basalts which are mafic (mafic means rich in magnesium and iron – two of the most abundant elements in the mantle).
Diamonds actually don’t form in kimberlites. Think of kimberlites as a conveyor belt bringing diamonds that form under high temperatures and pressures (from about 125 to 175 kilometers1) to the surface relatively fast, before they can reequilibrate (breakdown) into other compounds like graphite or carbon dioxide. Diamonds are not forever. Many an exploration program has had its hopes dashed with the discovery of kimberlite full of octahedral or other cubic forms of graphite — degraded diamonds2.
Exploration for diamonds can be excruciatingly frustrating. There are 6,400 known kimberlite pipes worldwide but only 30 or so have become viable mines — that’s about 0.5% chance that a discovered kimberlite will turn into a producing mine. It’s true, diamondniferous kimberlites are hard to find, but you don’t need many diamonds to make a mine. High-grade diamond kimberlites only contain a few carats per ton of rock. That’s enough to make any geologist rich beyond her dreams. Kimberlites form at greater than 200 kilometer depths (200 to 600 km) and are enriched in volatiles (e.g., carbon dioxide and water) that make the magmas not only buoyant but explosive. They literally “blow” through the upper mantle and crust in perhaps a matter of hours (rates postulated are about 14 km/hr) forming carrot-shaped pipes called diatremes (see the diagram below). The faster the better for diamond preservation. But they also have to pick diamonds up along the way or incorporate them as the magma forms. Kimberlites can contain as much as 25 to 50 percent rock within their magma acting as an elevator to the surface for mantle material helping geologists understand the mantle3.
Asbestos Wikipedia
After half a century or more of serious diamond exploration. we have learned that diamond-bearing kimberlites form below the cratons. The cratons are the ancient regions of continents containing rocks greater than 2 billion years old. There is still great debate about how the cratons formed, but every continent is rooted in these ancient environs. If you are looking for diamonds, go to the cratons. Before the 1980s, diamond kimberlite mines had been developed on every craton of all the continents except Antarctica and North America. Diamonds come from two major sources: mantle rock (e.g., peridotite) and eclogite (metamorphosed basalt). Diamond formation in peridotites occurred primarily in the Archean centered on a time about 3 to 3.3 billion years ago but some dates are as young as 1.9 billion years ago. Eclogite diamonds tend to be younger from 1 to 2.9 billion years ago.
Where does the carbon come from to form diamonds? No one knows for sure, but most researchers think that the carbon along with sediments and volatiles were subducted through plate tectonics (the ecologites brought up by kimberlites are likely ancient subducted ocean floor)4. I am interested, through my own research, on how the cratons formed and when subduction began. Many geologists pooh-pooh the idea that subduction could have begun so early in earth history so it is satisfying to see how diamond research supports the early existence of plate tectonics and subduction. My colleagues and I have contended for years that the cratons are the result of ancient subduction.
Imagine Chuck Fipke in the 1980s looking out over the vast expanses of northern Canada contemplating all the diamonds he believed had to be out there in the craton hidden below tons of glacial deposits. Those damnable glacial deposits were the reason no one had discovered pipes in Canada5. The map below shows the furthest extent of the glaciers 17,000 years ago and the site of the diamond pipes eventually discovered. Fipke also had to contend with De Beers, the giant cartel that controlled the world’s diamond markets. They were actively exploring with their practically unlimited resources. I worked for De Beers as a consulting geologist for a time in the mid 1990s in Russia, and I can assure you, they are a force to be reckoned with.
Base map from Wikipeida
By the mid 1980s, geologists had discovered that the mantle material brought up by kimberlites could aid them in their exploration thanks to a geochemist named John J. Gurney at the University of Capetown. Diamonds form in equilibrium at specific temperatures and pressures with other minerals more abundant than diamonds. Gurney, funded by Superior Oil, analyzed extensive mineral assemblages from kimberlites with and without diamonds and found that there are chemical signatures in the minerals that show up when diamonds are present. One of the more famous diagrams is that of the chromium and calcium concentrations in garnets from the mineral assemblages. Garnets fall into two groups on the diagram called G10 and G9 and virtually all garnets that occur with diamonds fall within the G10 field shown below. As mentioned before, diamonds can reequilibrate in kimberlites and become graphite or evaporate away as carbon dioxide. The diagram shows the line of stability under chromium saturation where diamonds will breakdown. Some diamonds remain stable in the graphite field because the conditions do not last long enough to degrade the diamonds. But if G10 garnets fall above the diamond-graphite equilibrium line it is a pretty sure bet you are on the right track for diamondiferous kimberlites. And that is precisely what Fipke kept finding in in his samples of glacial debris as he flew along with Blusson (who not only has a PhD but is a pilot) periodically sampling them. The long-gone glaciers were pointing the way.
After Nowicki et al., 2007
At the time in the mid 1980s, geologist understood the relationships between these indicator minerals and diamonds, but how could the information be used to find the kimberlites in the Canadian craton? What was unique about Fipke and his partner Blusson was the way they approached the problem. They knew that the glaciers were powerful enough to gouge out the relatively soft kimberlite and carry the indicator minerals long distances destroying any signs of the kimberlites at the surface and subsequently burying them under debris carried by the glaciers when they melted. They reasoned that they might be able to sample glacial deposits and “walk” the indicator minerals back to their source. Standard Oil liked the idea and funded their exploration at first. No one knew then that it would take eight years, millions of exploration dollars, and several companies before they hit pay dirt. De Beer’s geologists also knew the answer was in the glacial remains, but to them it was a nine to five job and the season ended after 8 weeks of summer collecting. For Fipke, it was a life’s dream, and nothing terminated his resolve collecting well into the cold months of the far north.
Fipke and Blusson focused on eskers (see the esker shown below) which are sinuous ridges of stratified sand and gravel deposited by water flowing in tunnels of ice within or under the glaciers. As the glaciers recede the ridges remain like compasses indicative of the direction the water and ice once flowed. If the glaciers rumbled over kimberlites, the proof would be in the streams that carried the glacial till away. They kept going even after Standard Oil called it quits. The G10 garnets kept telling them they were on the right road and the mining giant BHP believed them when they began running out of money. Dia Met, the company Fipke and Blusson formed, signed a sweet deal with BHP. BHP agreed to fund the exploration for a 51% stake. Within six months after teaming with BHP, Fipke had come to a point where the G10 garnets disappeared near Lac de Gras. Fipke knew he was close to the source. As the story goes, he noticed a lake from the air that looked like it sat in a bowl-shaped depression near where the G10 garnets disappeared. He had to have a sample of the rock in that depression. They landed the plane on the lake, rowed to shore, and started to dig, but after many hours they were still in glacial till. They decided to walk the shoreline for a better place to dig. That is when Fipke’s son Mark, found a piece of kimberlite. They were all ecstatic — the lake must sit on the pipe. Gurney eventually analyzed the mineral assemblage and verified that it was highly likely to be a diamond-bearing kimberlite. BHP quickly flew a geophysical survey which showed a distinct structure below the lake.
Esker in Sweden (Hanna Lokrantz Wikipedia)
BHP and Dia Met started quietly staking as much land around the lake as they could. Kimberlite pipes frequently occur in bundles so it was imperative that they obtain rights to as large a region as possible before word got out of the find. While they were staking, BHP flew a drill rig in by helicopter and cored 455 feet under the lake pulling out beautiful samples of kimberlite 33 feet below the glacial debris with 80 plus small diamonds. Canadian law requires that companies announce to their shareholders when a potentially profitable body is found. On November 12, 1991 they announced the results from the core including the fact that a few gem-quality diamonds had been recovered from the core. All hell broke loose, and the rush was on by large and small companies alike to stake as close to BHP’s claims as possible in the hopes that other pipes might be buried nearby. BHP would go on to discover more than 150 kimberlite pipes helping to make Canada the third largest producer of diamonds in the world. De Beers even found a few mines. Fipke and Blusson became billionaires overnight (if you don’t count the 8 years of exploration).
The image below shows the Etaki mine – one of the producing mines staked within Fipke’s original claims. The large circular depressions in kmberlite represent part of the open-pit mining operations BHP is running.
Ekati mines from the air (Google Maps)
- Shirey, S. B. and Richardson, S. H. (2011) Start of the Wilson Cycle at 3 Ga shown by diamonds from subcontinental mantle: Science 333, 434-436 ↩
- Pearson, D. G., Davies, G. R., Nixon, P. H., and Milledge, H. (1989) Graphitized diamonds from a peridotite massif in Morocco and implications for anomalous diamond occurrences: Nature, 338, 60-62 ↩
- Russell, J. K., Porritt, L. A., and Hilchie, L. (2013) Kimberlite: rapid ascent of lithospherically modified carbonatitic melts: In Pearson, D. G. et al, Proceedings of 10th International Kimberlite Conference Vol. 1 p. 195-210 ↩
- Nowicki, T. E., et al. (2007) Diamonds and associated heavy minerals in kimberlite: A review of key concepts and applications: Developments in Sedimentology, 58, 1235-1267 ↩
- Cross, L. D. (2011) Treasure Under the Tundra: Canada’s Arctic Diamonds: Heritage House Publishing Co ↩