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Tuesday, 25 October 2011

Intracratonic Basins

Intracratonic Basins
   The intracratonic sedimentary basins consist  in fills of large areas within continental crustal stable masses. They are characterized by deposits related to continental and shallow marine paleoenvironments, with significant gaps, hiatus between depositional megasequences. They have generally round or oval shapes, and have long histories of relatively slow subsidence. Classic examples of such notable are the basins Williston, Michigan and Illinois, in North America, Paraná Basin, Parnaíba, Solimões, Amazonas, in Brazil, Murzuk and Al Kufra, in Libya, Karoo and Congo in Africa, Surat in Australia, among others.


   The origin of these basins has set up a puzzle in geology. The tectonic reconstructions at Plate Tectonics paradigm is very difficult. The Theory of Earth Expansion offers a plausible explanation. In the Paleozoic Era, Earth could have a radius smaller than the current one. There were no extensive processes of oceanic expansion, much less what is so-called subduction of plates. Dominated continental environments such as alluvial, fluvial and deltaic, lakes, deserts, glacial events, and shallow seas, never deep marine oceanic sedimentation, as seen during and after the Mesozoic Era. Formation of Intracratonic basins would promote processes of crustal uplift buckling and bending of the marginal arches and depressions with precursors rifts which later would then be filled by marginal erosion of these arches, with episodic sedimentation of clastic, carbonate, salt, ecc.

Tectonic provinces of South America (Mantovani et al., 2001).  AB, Amazon Basin; AC, Amazon Craton; CA, Central Andes; CT, Chilenia Terrane; MP, Mantiqueira Province; NA, Northern Andes; NME, Northeastern Margin of South Atlantic Shield; P, Patagonia; PB, Paraná Basin; PCB, Phanerozoic collisional belts; PNB, Parnaiba Basin; RLPC, Rio de la Plata Craton; SA, Southern Andes; SFC, São Francisco Craton; SP, Southern Province. In green major areas dominate intracratonic basins.


North-south cross section of Muruzq Basin. (Modified after Pallas, 1980). Typical profile of intracratonic basinLarge intracratonic Paleozoic Basin, straddling the Boundaries of Algeria, Niger and Chad. The Basin is filled with sediment ranging in age between Cambrian to Quaternary, with maximum total thickness of more than 3000 meter in the central part. 

Intracratonic basins frequently are filled by Paleozoic sediments. At that time Earth probably was much small and there wouldn't deep basins, no subduction, no pangea, just shallow seas and continental sedimentation. Understanding of Earth's evolution is crucial to solve many problems enrooted by geological dogmas including origin of Intracratonic Basins.

16 comments:

  1. that was an impressive lecture...Thanku..

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  2. You are welcome. I believe that if we want to better understand the origin of the intracratonic basins we need to change our thinking about the evolution of the Earth.

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    1. I agree but am confused by the above presentation. I hope to get a handle on it soon. I like the illustration of the Niger-Chad Basin.

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  3. Hm there have been some really informative theories on intracratonic basins, this seems a bit outdated..

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    1. I might not be updated. Do you have references to new theories about origin of intracratonic basins? If so, could you list them? Thanks.

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  4. Do u mean that there is no deep marine deposits prior to Paleozoic?
    As to the mechanism of formation, though still debatable, there are many theories. You can say more about intracratonic basins than this. the relationship between expansion of earth and intracratonic basin formation is flawed

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    1. No, I did not say that there was no deep sedimentation prior to Paleozoic Era, but during it. During the Paleozoic Era dominated shallow not deep marine sedimentation. I do not think the statement of the Earth Expanding Theory is fail. It certainly explains a lot, but few give it importance, because they live in a paradigm.

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  5. What you've just said is one of the most insanely idiotic things I have ever read. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone who was unfortunate enough to stumble upon this is now dumber for having read it. I award you no points, and may whatever god(s) you believe in have mercy on your soul.

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    1. Very unhappy your comment. You need to study more, so it will not become ignorant.

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    2. I am also a geologist and I agree with Ronan. That was a waist of 10 minutes. Where the hell did you study geology?

      The super continents did all join and the rest of the world was covered by oceans.

      Mars is a lot smaller than Earth and therefore has cooled quicker so there is no more crustal movement.

      Also what science have you used to justify the world has doubled in size? You mention no numbers.

      I would like to know what your objective of this video is.

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    3. Dear Geologist.

      You cannot possibly be a geologist.

      And I don't even think English is your first language.

      Best regards,
      An actual geologist with a university degree

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    4. Dear anonymous, you are right! English is not my first language. You are wrong...I am geologist, but I think I've learned geology reading rocks, based on natural laws, of course, not dogmas present in books based on uniformitarianism. I recommend you study geology with humility and open mind. Try study publications of Samuel Warren Carey. Our knowledge about planet Earth and its evolution is so smaller as our minds. Thanks.

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    5. Dear Geologist,
      To be a geologist, think of (actual) geologists as a group of friends or a club that has a common interest. Now to get into this nerdy group or club, you must first succeed at a kind of initiation. This initiation is called UNIVERSITY.
      Furthermore this initiation awards you a UNIVERSITY DEGREE, the reason this UNIVERSITY DEGREE is not frowned upon by the human society (apart from uneducated conspiracy nutjobs) is because the knowledge gained is not from years of research trail and error and smart minds working together thesis after thesis arguing and discussing possibilities. Your way of self education and critical analysis of the natural world based on your own beliefs... blah blah blah i could go on for hours but how can you possibly claim to be open minded and not ignorant when you only take into consideration the opinions of uneducated people who are only educated by their own beliefs and blinded by seeing what they want to see (ignorance).. I am a student of Geology and in no way shape or form will i ever try and exclude information or shield anyone from knowledge and research I will do in the future. Your claim of someone not telling you something about earth history is absolutely preposterous, what bad could possibly arise from such a conspiracy?
      Read a F*%@# buck you idiot.

      kind regards,
      One of the geologist (to be) not telling truth..

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    6. “Geology is the prisoner of several dogmas that have had widespread influence on the development of scientific thought.” — William R. Corliss, 1975


      “It is a singular and notable fact that, while most other branches of science have emancipated themselves from the trammels of metaphysical reasoning, the science of geology still remains imprisoned in ‘a priori’ theories.” — Sir Henry H. Howorth, 1895

      I hope this is enough for a stupid approach...

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  6. You may like to see the website at: www.expansiontectonics.com for a better understanding

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  7. Thank you very much Dr. Maxlow.

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