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(Most irrelevant groups removed. I Read in sci.astro)
"George" wrote: Having spent years studying the strata, I can tell you with absolute certainty that I don't need a geology book to tell me the facts of the coal-bearing strata in Kentucky, and surrounding states. The earliest known occurrence of coal is found in the Upper Chester of Southern Indiana (upper Mississippian). Coal seams occur periodically from there up into the upper Pennsylvanian. The coal has many associated plant fossils, and the occasional trace animal fossils, and many secondary minerals associated with them. From the disorganized bits and pieces of info I've come across over the years, I've gotten the impression that coal formed from woody plants, until the first fungi or bacteria (which?) capable of digesting cellulose developed. And that oil formed from the bacterial mats which I gather were the only life form on Earth for a billion years or more. Are those impressions about right? -- Jeff, in Minneapolis .. |
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![]() "Jeff Root" wrote in message om... (Most irrelevant groups removed. I Read in sci.astro) "George" wrote: Having spent years studying the strata, I can tell you with absolute certainty that I don't need a geology book to tell me the facts of the coal-bearing strata in Kentucky, and surrounding states. The earliest known occurrence of coal is found in the Upper Chester of Southern Indiana (upper Mississippian). Coal seams occur periodically from there up into the upper Pennsylvanian. The coal has many associated plant fossils, and the occasional trace animal fossils, and many secondary minerals associated with them. From the disorganized bits and pieces of info I've come across over the years, I've gotten the impression that coal formed from woody plants, until the first fungi or bacteria (which?) capable of digesting cellulose developed. And that oil formed from the bacterial mats which I gather were the only life form on Earth for a billion years or more. Are those impressions about right? -- Jeff, in Minneapolis Sure, woody plants like lepidodendron, but also peat, ferns, and other plants as well. I've seen fossilized logs brought out of mines that weighed as much as four tons, and were ten feet long, and three feet in diameter. As for the bacterial mats, I don't know that I would go so far as to say that they were that significant to the diagenesis. That is, bacteria were certainly important in the reducing environment of the marshes and swamps that eventually formed the coal. But it is also important to understand the importance of pressure and temperature of the coal forming process. As we all know oil begins to break down at about a temperature of 150 degrees C. As such, much of the parafins, volatailes and long chain hydrocarbons would have been removed from the coal if the temperature had been much higher than this, rendering most of it useless as a fuel source. So we have an upper constraint on the temperature of formation. Yet it is not unreasonable to assume that temperatures in the neighborhood of 100 degrees C were present when the coal formed due to the fact that many of the high vapor pressure hydrocarbons were removed from the coal during its formation. As for the bacteria being the only life forms for a billion years, that may have been true for earth's ealiest history (i.e., 2-3 Bya) but it was certainly not true for the 300 million years prior to the formation of coal in the Eastern US. The earliest known land plants are Silurian in age. And of course, there are faunal communities that go back into the pre-cambrian (yeah, I know, its an outdated term - old habits die hard). Indeed, the earth (especially the oceans) were full of life prior to and during that time. I have Osagian-aged sharks teeth and dorsal bone (the only bone in sharks of any species that I am aware of) found in association with a huge crinoid faunal community in the Muldraugh member of the Borden formation in Central Kentucky. I have also found a coelecanth in the upper Chester of Southern Indiana in association with a blastoid faunal community. And there are, of course, the famous Devonian-aged fossil beds at the Falls of the Ohio State Park, on the Ohio River, which contain over 700 hundred species of marine animals. |
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"George" replied to Jeff Root's question:
From the disorganized bits and pieces of info I've come across over the years, I've gotten the impression that coal formed from woody plants, until the first fungi or bacteria (which?) capable of digesting cellulose developed. And that oil formed from the bacterial mats which I gather were the only life form on Earth for a billion years or more. Are those impressions about right? Sure, woody plants like lepidodendron, but also peat, ferns, and other plants as well. I've seen fossilized logs brought out of mines that weighed as much as four tons, and were ten feet long, and three feet in diameter. As for the bacterial mats, I don't know that I would go so far as to say that they were that significant to the diagenesis. That is, bacteria were certainly important in the reducing environment of the marshes and swamps that eventually formed the coal. But it is also important to understand the importance of pressure and temperature of the coal forming process. You imply here and below something that you don't actually say, and which I have never heard befo That coal formed from oil. I was under the impression that oil formed over a much longer period than oil did, much longer ago, and from different source material. But you imply that the difference between coal and oil is that coal is oil which has undergone further changes in the Earth. Is that what you're saying? As we all know oil begins to break down at about a temperature of 150 degrees C. That may be widely-known, but I didn't know it. As such, much of the parafins, volatailes and long chain hydrocarbons would have been removed from the coal if the temperature had been much higher than this, rendering most of it useless as a fuel source. Longer chains break down first? Do they break into random-size pieces or do tiny pieces (such as methane and ethane) break off from the big ones? What happens to the bits? Do unbranched chains break down at lower temperature than branched chains? So we have an upper constraint on the temperature of formation. Yet it is not unreasonable to assume that temperatures in the neighborhood of 100 degrees C were present when the coal formed due to the fact that many of the high vapor pressure hydrocarbons were removed from the coal during its formation. As for the bacteria being the only life forms for a billion years, that may have been true for earth's ealiest history (i.e., 2-3 Bya) but it was certainly not true for the 300 million years prior to the formation of coal in the Eastern US. I wasn't suggesting that bacterial mats had *anything* to do with the formation of coal-- just oil. But I know that some modern-day bacteria, like many fungi, are able to digest cellulose. I wondered whether the advent of those cellulose- eating bacteria and/or fungi brought an end to coal formation. -- Jeff, in Minneapolis .. |
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![]() "Jeff Root" wrote in message om... "George" replied to Jeff Root's question: From the disorganized bits and pieces of info I've come across over the years, I've gotten the impression that coal formed from woody plants, until the first fungi or bacteria (which?) capable of digesting cellulose developed. And that oil formed from the bacterial mats which I gather were the only life form on Earth for a billion years or more. Are those impressions about right? Sure, woody plants like lepidodendron, but also peat, ferns, and other plants as well. I've seen fossilized logs brought out of mines that weighed as much as four tons, and were ten feet long, and three feet in diameter. As for the bacterial mats, I don't know that I would go so far as to say that they were that significant to the diagenesis. That is, bacteria were certainly important in the reducing environment of the marshes and swamps that eventually formed the coal. But it is also important to understand the importance of pressure and temperature of the coal forming process. You imply here and below something that you don't actually say, and which I have never heard befo What? No. You misunderstand me. The decomposition products of marsh and swamp deposits (decomposed organic matter) form coal under similar chemical and environmental conditions. You can even get oil out of coal, hence the coal gasification process. But oil is different in that being liquid, not solid, it is more refined, and can migrate through porous rock where it gets trapped into reservoirs in geologic structures. That coal formed from oil. Not at all. As I stated above, coal is formed from the decomposition of organic matter (peat, dead trees, ferms, and other plant and organic material). But oil is found in some coal, and can be extracted from it. I was under the impression that oil formed over a much longer period than oil did, much longer ago, and from different source material. That is mostly true. However, oil is also found in coal, and can be extracted from it. Many of the same hydrocarbons found in coal are also found in oil. But you imply that the difference between coal and oil is that coal is oil which has undergone further changes in the Earth. Is that what you're saying? No, its the other way around, but not in all cases. Both form in reducing environments, but oil is mobile, and can migrate, as mentioned above. As we all know oil begins to break down at about a temperature of 150 degrees C. That may be widely-known, but I didn't know it. The fluorite found in the Kentucky-Illinois fluorspar district often has inclusions of oil in it. The presence of this oil provides a temperature constraint on the formation of the fluorite, since oil breaks down at temperatures above 150 degrees C. As such, much of the parafins, volatailes and long chain hydrocarbons would have been removed from the coal if the temperature had been much higher than this, rendering most of it useless as a fuel source. Longer chains break down first? Do they break into random-size pieces or do tiny pieces (such as methane and ethane) break off from the big ones? What happens to the bits? Do unbranched chains break down at lower temperature than branched chains? I don't know the exact sequence, but I would assume that the volatiles outgas first (such as methane, benzene, toluene, ethylbenzene, and the xylenes, etc. The longer chains would obviously take longer to break down, as we see in the difficulty in cleaning up many oil spills and discharges into soil and ground water of heavy fractions such as #2 fuel oil, and diesel. So we have an upper constraint on the temperature of formation. Yet it is not unreasonable to assume that temperatures in the neighborhood of 100 degrees C were present when the coal formed due to the fact that many of the high vapor pressure hydrocarbons were removed from the coal during its formation. As for the bacteria being the only life forms for a billion years, that may have been true for earth's ealiest history (i.e., 2-3 Bya) but it was certainly not true for the 300 million years prior to the formation of coal in the Eastern US. I wasn't suggesting that bacterial mats had *anything* to do with the formation of coal-- just oil. But I know that some modern-day bacteria, like many fungi, are able to digest cellulose. I wondered whether the advent of those cellulose- eating bacteria and/or fungi brought an end to coal formation. -- Jeff, in Minneapolis Good question. Sounds like a dissertation paper for someone to me. Interested? |
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![]() "Jeff Root" wrote in message om... "George" replied to Jeff Root: From the disorganized bits and pieces of info I've come across over the years, I've gotten the impression that coal formed from woody plants, until the first fungi or bacteria (which?) capable of digesting cellulose developed. And that oil formed from the bacterial mats which I gather were the only life form on Earth for a billion years or more. Are those impressions about right? Sure, woody plants like lepidodendron, but also peat, ferns, and other plants as well. I've seen fossilized logs brought out of mines that weighed as much as four tons, and were ten feet long, and three feet in diameter. As for the bacterial mats, I don't know that I would go so far as to say that they were that significant to the diagenesis. That is, bacteria were certainly important in the reducing environment of the marshes and swamps that eventually formed the coal. But it is also important to understand the importance of pressure and temperature of the coal forming process. You imply here and below something that you don't actually say, and which I have never heard befo That coal formed from oil. What? No. You misunderstand me. Ok. That's a relief. :-) The decomposition products of marsh and swamp deposits (decomposed organic matter) form coal under similar chemical and environmental conditions. You can even get oil out of coal, hence the coal gasification process. But oil is different in that being liquid, not solid, it is more refined, and can migrate through porous rock where it gets trapped into reservoirs in geologic structures. How well are coal and oil formation processes understood? Very well. Is water in large quantities ("marsh and swamp") thought to be essential for both processes? I don't know how important they are for the formation of coal, but there is usually a lot of ground water in most ground water that has to be contolled during the mining process. Many water wells in Eastern Kentucky are contaminated with iron and natural gas originating from the coal. Of course, oil usually migrates with a lot of water, and is usually saturated brine water, which also has to be controlled. Or would very small quantities (maybe just humid air) suffice? Air is not really a large at all in either, since they nearly always form in a reducing environment. Did the source matter have to be buried, or could coal and/or oil form while exposed at the surface (perhaps in a very different atmosphere from today's)? Coal is formed after burial, pressure of compaction, and moderate heating (100 degrees C or less). Oil is formed through several processes, always in a reducing environment, but always within the subsurface. Sometime it seeps to the surface, but have already formed at that point. I would interpret "more refined" to mean "more changed from the original mix of material" and "more separated into its component parts". As I understand it, more refined means the process (much of which involves biological digestion, a conversion process, and heating under pressure in the subsurface) has purified the oil, removng impurities and compounds which the bacteria digest, such as sulfur, although sulfur is usually one component that has to be removed during the refinement process before it is used. It is usually separated in the sense that in its early stage of formation the brine water is intermixed with the oily solution, as well as some gas. The refinement process in the ground creates a lot of natural gas that is usually burned off when the oil is recovered. Is that what you mean? Does crude oil contain fewer different compounds than coal? Oil contains more compounds, but they are not all the same. Coal contains more phenyl compounds, and more creosote, whereas oil contains more polynuclear aromatic compounds like naphthalene, acenapthylene, etc. Both contain a lot of carcenogenic compounds. Has the vast majority of the oil in the ground migrated and pooled, or is a large fraction of the total just a minor contaminant in the rock which contains it? Or what? Understand that when an oil field is developed, the most that can be recovered is in the neighborhood of 20%. The rest is locked up in much less permeable rock, or consists of heavier fractions, like tars.. And after the pressure is reduced from pumping, usually water or steam has to be injected into the reservoir to increase the pressure and extract more oil. Sometime the rock is fractured with explosives to increase permeability. Removing the remaining 80% has long been a tremendous problem and expense for the oil industry. But as for whether most is pooled or just a minor fraction of the total, most porous sedimentary rocks contain some minor amounts of hydrocarbons. The question for oil companies is what can be recovered. Most is not mature enough to use, or of not enough quantity to justify the expense of recovery. So I would say that most oil in the ground is in small quantities. The large reservoirsare rare. Many wells show what at first appears to be large plays, but end up tapering off quickly to much lower recoverable amounts. That coal formed from oil. Not at all. As I stated above, coal is formed from the decomposition of organic matter (peat, dead trees, ferms, and other plant and organic material). But oil is found in some coal, and can be extracted from it. I was under the impression that oil formed over a much longer period than oil did, much longer ago, and from different source material. That is mostly true. However, oil is also found in coal, and can be extracted from it. Many of the same hydrocarbons found in coal are also found in oil. But you imply that the difference between coal and oil is that coal is oil which has undergone further changes in the Earth. Is that what you're saying? No, its the other way around, but not in all cases. Both form in reducing environments, but oil is mobile, and can migrate, as mentioned above. I don't see why you emphasize that fact. It may be crucial to where the oil is found today and how it is extracted, but doesn't appear to have anything to do with how it formed. Coal and oil seem to usually be found separate from each other. Not miles apart, but hundreds or thousands of miles apart. That is not really true. The first oil field developed in Kentucky, for instance was in the Eastern Kentucky coal field. The first oil fields developed in West Virginia and Pennsylvania was developed in proximity to bituminous and anthracite coal deposits. The Oil in the Persian Gulf and in the Southern US formed under different circumstances. That oil was formed from the decay of rapidly buried plankton and reef deposits, as was the oil found in Texas, Oklahoma, and the gulf of Mexico. You said in your first reply: As for the bacterial mats, I don't know that I would go so far as to say that they were that significant to the diagenesis. That is, bacteria were certainly important in the reducing environment of the marshes and swamps that eventually formed the coal. Do you mean you don't think oil formed from bacterial mats? What I mean is that although bacteria plays a huge role in the formation of oil, the source material in many locations is usually plankton, organic material from reefs, and algae. The bacteria decays this material after burial in a reducing environment. And of course, oil is also produced as a result of the formation of coal. Since nothing had evolved yet to eat the bacteria, there must have been plenty of organic matter available. I guessed that that is the reason there is so much oil in the Earth today: A billion years or two worth of dead bacteria piled up. Actually, 70% of all oil is of Mezozoic age, 20% is of Cenozoic age, while 10% is of Paleozoic age. No oil reserves have been found to be older than Paleozoic age. As such, much of the parafins, volatailes and long chain hydrocarbons would have been removed from the coal if the temperature had been much higher than this, rendering most of it useless as a fuel source. Longer chains break down first? Do they break into random-size pieces or do tiny pieces (such as methane and ethane) break off from the big ones? What happens to the bits? Do unbranched chains break down at lower temperature than branched chains? I don't know the exact sequence, but I would assume that the volatiles outgas first (such as methane, benzene, toluene, ethylbenzene, and the xylenes, etc. The longer chains would obviously take longer to break down, as we see in the difficulty in cleaning up many oil spills and discharges into soil and ground water of heavy fractions such as #2 fuel oil, and diesel. That doesn't directly confirm my guess: That you were saying that paraffins and other long-chain hydrocarbons are the first to break down when the temperature goes up. Is that what you were saying? No. I wasn't suggesting that bacterial mats had *anything* to do with the formation of coal-- just oil. But I know that some modern-day bacteria, like many fungi, are able to digest cellulose. I wondered whether the advent of those cellulose- eating bacteria and/or fungi brought an end to coal formation. Good question. Sounds like a dissertation paper for someone to me. Interested? Me? Moderately interested, but highly incompetent. -- Jeff, in Minneapolis Everyone starts from lack of knowledge. Edison was a kluts and misbehaved in school. His acheivement was that he was an obsessive-compulsive. He rarely slept, and was constantly thinking about how to make things and solve problems. He wasn't particularly intelligent, or particularly well liked, just determined, and he stole some of his best "inventions". Sometimes people just get lucky. I'm not a particularly talented geologist (at least I don't think so). But I was lucky enough to stumble, along with a partner, across one of the most significant Mississippian-aged crinoid locations in the Central US about 15 years ago (30 genera, 74 species, 8 new species, two new genera, and five specimens that were more complete than the holotypes). We also found crinoid stems that were over 7 feet long, and 3/4 inch in diameter. For me, it was a find of a lifetime. We were actually looking for minerals. Like I said, sometimes you just get lucky. It often takes a lot of hard work, but if you enjoy the work, and are forever inquisitive, you can acheive a lot. |
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