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308 Beacon of Hope

About arc

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    Land of volcanoes
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    Is mantle convection theory as good as we can get? Can it explain the variation in the world's divergent plate boundaries? The depth of the Mariana trench? The Basin and Range area? The San Andres fault? Current and past mountain building mechanics?

    Please visit my "Plate Tectonic Mechanism?" thread in speculations and tell me what you think.

    Is it time for a new model of plate tectonics?

    In the last year and some months I have been quite busy writing a hypothesis concerning the thermal heating of the planets that possess magnetic fields and the several moons that exhibit the early development of these electro-magnetic phenomena that in the Earth's case I believe drive the various geologic processes that are currently observed and debated.

    You can view this work in two versions;

    The first is the Earth's geologic processes as seen through the thermal forcing of a variable electro-magnetic field.

    The second is where a broader examination is made with a more speculative assessment of these planets and their field generating mechanisms that also incorporates the above mentioned work in a more comprehensive and unified presentation.
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  1. arc

    Can you help me identify this mineral?

    Yes, I agree it doesn't look sedimentary, one of the tests is it will spark when a sharp edge is struck like a match stick off of a piece of iron. The site below gives a good description of the characteristics of Chert and its variations such as Jasper. There are some nice images that show texture and color variation. "Jasper is a hematite-bearing variety. Hematite is an iron oxide that is the most widespread source of red color in minerals and rocks. The sample is from the Løkken ophiolite in Norway. It is associated with SEDEX-type magnetite-hematite iron ore formed by hydrothermal activity at the spreading zones of mid-ocean ridges. Width of sample 13 cm." "It is usually either dull or semivitreous. It may have many colors, depending on the nature of impurities. Most common shades are gray, white, blue, green, yellow, black, and red. White coloration is usually given by carbonate impurities; organic matter or clay gives black color; red, yellow, and brown tones are due to hematite, green variety may contain chlorite or smectite from diagenetically altered volcanic tuffs. It occurs usually as nodules in carbonate rocks, especially well-known are chalks with chert (flint) nodules in Western Europe. This rock is often bedded – rhythmically interlayered with chalk, shale or in some cases hematite. The latter is known as a banded iron formation (BIF) which is the principal iron ore upon which our society relies. Chert is in most cases a biogenic rock, it is made of siliceous tests of diatoms, radiolarians, siliceous sponge spicules, etc. Sometimes microscopic fossilized remains of these sea creatures may be preserved in these rocks. Their siliceous tests are not made of quartz initially, but after burial, compaction, and diagenesis, opaline siliceous sediments transform to quartz. Although the material it is made of ultimately came from siliceous tests of marine species, the rock itself is often not deposited in situ. It may move as a silica-rich liquid and form nodules in rocks by replacing the original (usually carbonate) material. So chert is also sometimes said to be a rock of chemogenic origin. Bedded variety seems to be often associated with turbidity currents."
  2. arc

    Can you help me identify this mineral?

    It's a sedimentary rock derived from clay. Iron oxides will give it the red color, I've had a small green piece in my coat pocket for over a year since I found it.
  3. arc

    Can you help me identify this mineral?

    It looks like red chert.
  4. arc

    SFN Slogan

    I think it should be somewhat humorous in an ominous or inauspicious way. 1. "Omnes relinquite spes, o vos intrantes" (Abandon all hope ye who enter here) 2. "Welcome to SFN - where ideas are pounded into dust" 3. "Welcome to SFN - where even the greatest ideas are pounded into dust" 4. "Welcome to the SFN destructive testing laboratory - where your best ideas are pounded into dust" 5. "Welcome to the SFN destructive testing laboratory - where every great idea is pounded into dust" 6. "Welcome to the SFN destructive testing laboratory - Omnes relinquite spes, o vos intrantes" (Abandon all hope ye who enter here)
  5. What is going on with all of these people who have come on here in the last little while and changed/added their profile picture? They all seem to have joined several years ago, only were on the site for one or two days and made zero posts, but now they suddenly decided to show up and change/add their picture. Seems odd.
  6. arc

    Plate Tectonics: A Modern Myth?

    Hello Doug, welcome to SFN. The biggest problem I see here is you do not cite any scientific research to support your conjecture. These independent observations of the natural world are not just needed, but they are actually required to raise your idea up to a more credible level of predictive strength. Right now all you have is your words describing the physical arrangement of the Earth’s crust as seen in the images that you yourself have supplied. So, now all I need to do at this time to falsify your idea is to cite one or more credible sources that will refute your very weak speculation. For example, your analysis appears to focus entirely on some manner of extensional forces that have in some manner moved the described crustal sections away from each other. You then conclude: “This would appear to leave us with only one remaining option for an Earth dynamic: Earth expansion.” This would undoubtedly require the crust to be predominantly in a state of tension to separate the crust in the manner that you have described above. I now simply need to counter your claim with contrary evidence from scientifically reputable sources that the crust is instead at this moment in a state of compression. MARIA T. ZUBER Department of Geological Sciences, Brown University, Providence, Rhode Island "As most of the oceanic lithosphere is in a state of net compression, the question arises as to why intraplate deformation has developed in these regions and not in others." On top of this contradictory evidence above is the fact that this scientifically observed and measured compression is just part of a much broader set of observations of additional and even greater compressive forces that have been measured and described. http://ceas.iisc.ern...h_geology06.pdf Gravitational potential energy of the Tibetan Plateau and the forces driving the Indian plate Attreyee Ghosh, William E. Holt Department of Geosciences, State University of New York, Stony Brook, New York 11790, USA Lucy M. Flesch* Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA A. John Haines† Bullard Laboratories, University of Cambridge, Cambridge CB3 0EZ, UK ABSTRACT "We present a study of the vertically integrated deviatoric stress field for the Indian plate and the Tibetan Plateau associated with gravitational potential energy (GPE) differences. Although the driving forces for the Indian plate have been attributed solely to the mid-oceanic ridges that surround the entire southern boundary of the plate, previous estimates of vertically integrated stress magnitudes of 6–7 1012 N/m in Tibet far exceed those of 3 1012 N/m associated with GPE at mid-oceanic ridges, calling for an additional force to satisfy the stress magnitudes in Tibet. We use the Crust 2.0 data set to infer gravitational potential energy differences in the lithosphere. We then apply the thin sheet approach in order to obtain a global solution of vertically integrated deviatoric stresses associated only with GPE differences. The multitudes of mountain ranges around the world are without a doubt one of the most dramatic expressions of compressive forces observed on the planet’s surface. Both in the sense that the structures are compressing through gravity the surrounding crustal plates, but also, they themselves are in turn pushing back, otherwise the mountains would be spreading out over the surrounding area and outwardly displacing these same crustal plates. ANNALS OF GEOPHYSICS, SUPPLEMENT TO VOL. 49, N. 1, 2006Mountain uplift and the Neotectonic PeriodCLIFF D. OLLIERSchool of Earth and Geographical Sciences, University of Western Australia, Perth, Australia 9.2. EXAMPLES 9.2.1. Tibet, Himalayas, Kunlun Mountains(As an example, consider the timing of uplift in Tibet and its bordering mountains. Gansser (1991) wrote: «... we must realize that the morphogenic phase is not only restricted to the Himalayas but involves the whole Tibetan block. This surprising fact shows that an area of 2500000 km2 has been uplifted 3000-4000 m during Pleistocene time and that this uplift is still going on.» In places the uplift rate is 4.5 mm/yr (five times the maximum in the European Alps). In short the Expanding Earth hypothesis has no answer to these massive structures. With just a few scientifically valid research papers a hypothesis without any similar support can be trivially shown that its supposition is false. Here is a link to a ResearchGate discussion on Plate Tectonics started by a purveyor of the Expanding Earth hypothesis; You will see how poorly the idea can be explained and defended. One particular fact presented by a geologist was very robust and of course ignored; Scot Krueger Massachusetts Institute of Technology "The Earth is not expanding. We have a global network of geodetic stations which have determined the relative motions of thousands of points on the planet's surface for the last several decades and the net motions add up to zero for any global circuit. All the observed domains (the plates) which are semi-rigidly separating are matched by other domains which are converging. The geodetic data strongly support plate tectonics and refute the expanding earth concept. The expanding earth hypothesis is a simplistic notion that has been examined repeatedly for well over a century and repeatedly found wanting. This is an example of why peer reviewed science is so critical, as all it takes is one newbie with a seafloor map and a pair of scissors to decide they have rediscovered an old "truth" and in the world of uncontrolled access on the internet they can force a lot of practitioners to waste a lot of time reviewing and repeating old work to knock down these spontaneous visions of grandeur. I know of what I speak because I have had to whack this mole repeatedly over my entire career as a global tectonicist."
  7. arc

    History Section

    History has become much more subjective to broader opinions as our society has become more diverse in a multitude of aspects. You mention Columbus; did you know the Italians had made quite a big deal about him at the Columbia Exposition and were quite peeved when the Scandinavians moored a Viking ship within sight of there pavilion. So, you can now add an indigenous eliment to the disscusion and it could get rather contentious due to emotional elements involving religion, race, genicide, geography and so on. I would wager many conversationists would struggle to stay out of the potentionally contentious political aspect of the subjects. Look at the religion and politics sections for example. Don’t get me wrong though, I enjoy talking history as much as anyone, but the key word here is enjoy.
  8. arc

    History Section

    There is, its about planetary history. We call it Geology.
  9. arc

    Thin wall plastic ducting ?

    The building codes require ducting to be metal to prevent fire from having an avenue to spread between rooms and floors, the gypsum board is part of the same overall strategy to slow the spread rate of the fire to increase the escape time.
  10. arc

    Is there a golden rule in movie making?

    I love the older films where it appears they had some of the local citizens as extras. The Blob from 1958 had the theater scene where almost every person young and old who ran out of the building to escape the monster were grinning and laughing. It looks as unconvincing now as it did when I was 8 years old. This clip below appears they may have slightly sped up the film to help hide the smiles and/or add some needed tension. It's in Spanish BTW.
  11. arc

    Iceberg to Capetown

    Pleasure is mine, I love this kind of stuff. Much of my childhood was spent reading old Popular Science mags from the decades before I was born, they were full of this kind of grand, over the top "soon we will be (fill in blank) extravaganzas. One Idea that popped into my head and then discarded; was to build an underwater pipeline, could the pressure on the outside counter the pressure needed on the inside? How many relay pumps would be needed at depth? OK, too complex. How about using geothermal heat at the source to generate the electric power for the processing and melting of the ice that would then be loaded into massive bladders that floated at almost neutral buoyancy. They would be sent off with autonomous guidance systems operating electric propulsion systems powered from solar voltaic receptors integrated into the bladders surface. They would be monitored from satellite and make up for their smaller volume and slow progress by being very low cost to operate and one of many in a vast fleet that would regularly arrive and then act as the destination's storage facility, no need to pump it into tanks on shore. They would just need to hook up a hose pipe and draw directly into the distribution system. The bladders would then be stacked on autonomous barges to be driven back to the source. Hey, you think I and my investors are going to let you have this whole market for yourself?!!!
  12. arc

    Iceberg to Capetown

    I'm sure Marc has already thought this through because he's pretty detail oriented, but it would seem that just converting the ice to water and pumping it into a tanker at the source and then pumping it out at the destination would be the most efficient process due to several factors. Towing the berg involves losing a rather large percentage due to melt, not only during transport but also at the destination when it must be processed quickly to prevent continual loss. Towing an ice berg is really no different then putting it in a tanker that has very large holes in its tanks allowing spillage of its cargo in route. And of course the tanker is most efficient in terms hydrodynamics. Another problem is the bergs will periodically roll to adjust as the ice below surface melts quicker then the ice above the water line. Having tow lines pulled over or under the burg could be quite exciting for the crews involved and would likely lead to their disconnection by breakage or intervention that would then result in considerable delays for reattachment, and putting crews up close to reattach the lines would be almost criminally irresponsible if you could find anyone brave enough to get that close to an unstable massive block of ice of those proportions. An interesting article;
  13. arc

    Is this really that bad?

    Years ago my employer purchased a new crane truck for me to operate; it was equipped with the customary duel air horns on top of the cab above the driver’s seat. A cord in the cab was connected to some linkage that passed through a rubber seal in the roof to where it then connected to a valve assembly on the air horns. On what may have been the first or second day of driving it; I was pulling out onto a street near an intersection just as the traffic light changed to red for the direction I was intending to go (right turn). There was about two car lengths of empty traffic lane extending from the driveway where I was waiting, to the stop line at the intersection. There was only one car that was immediately approaching from the left, but a block or so down the way was what looked like an endless string of cars. I anxiously waited for the young woman driving that first car to drive past me so I could pull in behind her before all those other cars came. (This town is known for how the cars and the traffic lights seem timed to conspire against you. And if someone would take up the left turn lane at the light I would not be able to make the turn into the street because the truck is so long, it was go now or wait much later in this regard) The young woman, who looked to be in her early twenties, stopped an entire car length short of the intersection, just past the front of my truck, so close I could not even put my bumper into the street. I put my hand in the center of the steering wheel where a padded horn button was located and lightly pressed down . . . nothing happened!, the smaller “car” like horn, that my previous trucks had been equipped with, was either malfunctioning or deleted by this manufacturer. As I looked back down the street at those fast approaching cars I reached for the air horn, I had only used the air horn in this truck once but I knew from using the ones on my old trucks that all I had to do was just barely pull the cord to let a little bit of air into the horns to make a small little squeak so as to get the young woman’s attention. Well, the air pushed open the valve and let out a blast so loud it caused the poor girl to jump in her seat as she quickly hit the gas to get out of the way. Worst yet, the horn would not shut off, I let the cord go completely slack at the first squawk but the valve stayed open, and as I pulled in behind her car I continued to try to release the valve only to make it louder!!! By now, she was sitting at the light pleading through her rear view mirror to the deranged psycho truck driver not to kill her. I could only continue to frantically yank on the cord while cussing at it in the most colorful display of language and what probably appeared to her as the angry shaking of my raised left fist. The light finally changed and we preceded slowly ahead, the horn shrieking its monotone death wail, and her, now turning her upper body to directly plead for her life between her car’s headrests while I continued my assault on the horn cord. We traversed in front of a gas station with probably a dozen people standing motionless as the spectacle slowly passed and then stopped behind the cars waiting for the next signal to change. By this time the young lady was so terrified I’m sure she thought about abandoning her car and making a break for safety. But the traffic began to move again and we continued on with her pleading for her life and me yelling and shaking my fist. When I finally reached the next intersection I couldn’t take her terrified gaze and the angry stares of the bystanders anymore and made a left turn against the signal to get to a large parking lot where I could finally disarm this WMD.
  14. arc

    The Official JOKES SECTION :)

    Just goes to show, not all sheep behave like . . . . . . well . . .sheep
  15. arc

    What's the only question that matters?

    The one that all men’s fate hangs in the balance of - Does this make my butt look big?