Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Carolina Bays

  1. Jun 19, 2011 #1
  2. jcsd
  3. Jun 19, 2011 #2

    Astronuc

    User Avatar

    Staff: Mentor

    Last edited by a moderator: May 5, 2017
  4. Jun 21, 2011 #3

    Dotini

    User Avatar
    Gold Member

    Hi Mat,
    It appears you would like to know the origin of Carolina Bays, which formed on earth prior to the Holocene. The wikipedia entry you linked mentioned two broad categories of possible origin - that "these features were created by forces within the Earth, or that they were gouged by an astronomical event or set of events". The wiki entry concluded by rejecting the impact hypothesis, as you note. However, the geomorphology explanation runs into troubles, too, for instance the wiki reference to the spring sapping ideas of D.W. Johnson, "The Origin of the Carolina Bays" New York: Columbia University Press, is refuted as violating the conservation of energy, http://www.jstor.org/pss/30071107. So you do have a credible mystery here.

    As an alternative, *Corliss cites the research of Y. Otsuki, physics professor of Waseda University, into plasmoids (to include plasma vortices), which hint at a sort of impact, not merely ballistic, following on from air bursts. For instance, a body disintegrates, say icy charged hailstones produced in the ionosphere, producing an ion trail to ground, resulting in something like lightning and its effects. In order to apply, these effects must have existed on scales larger than lightning effects known to occur now in the Holocene.

    *"Science Frontiers: Some Anomalies and Curiosities of Nature", William R Corliss

    Respectfully submitted,
    Steve
     
    Last edited by a moderator: Apr 26, 2017
  5. Jun 21, 2011 #4

    Astronuc

    User Avatar

    Staff: Mentor

    There is plenty of time for erosion and accumulation of organic matter. The fact that they fill with water means that rocks and minerals would be carried to the depressions and accumulate over time. Then vegetation would grow in the water or along the banks, and sooner or later die. Leaves from deciduous trees are shed annually, so they would accumulate in the water. Nor surprises there.
     
  6. Jun 22, 2011 #5
  7. Jul 30, 2011 #6
    It has been well shown that the gentle depressions are unlikely to be impact structures, for many reasons - depth-to-diameter ratio being only one aspect. Douglas Johnson, in his 1942 tomb on the subject of "The Origin of the Carolina Bays" cited numerous additional reasons why his findings were not supportive of an impact mechanism. Among those is an observation that the sand in the rim and comprising the sheet of sand surrounding the bays has no direct relationship to the strata beneath the bays, nor are those strata disturbed by the presence of the overlying bay. Johnson also noted that antecedent drainage channels mapping through numerous bays seemed to have survived the creation of the bays, something that would be unlikely if they were carved out by impact processes.

    You might get an interesting perspective by viewing the bays in high-resolution LiDAR-generated digital elevation maps.
    - Michael
     
    Last edited by a moderator: Sep 8, 2012
  8. Aug 1, 2011 #7
    Are they odd? Similar features are found throughout the world in low-lying coastal areas. Louisiana's swamps are very similar.
     
  9. Aug 1, 2011 #8
    The "Citronella" ponds in LA have been mentioned in listings of CB-like structures in the US. I have not identified any publicly available LiDAR in those areas of LA to inspect for the robustness of planform shape seen in further east.

    Oriented lakes in the Siberian Arctic have a similar presentation to those in Alaska and the NWT, and oriented oval lake collections have been reported in South Africa, Australia and Argentina. The creation of similar structures right along coastlines (see attached from Siberia) seem the most similar to Carolina bays in shape - geometrically pure shapes. The shoreline process was discussed by Cooke in 1934, where he proposed Atlantic shoreline lagoons morph into chains of lakes. I find it quite persuasive, as did many others back in the 30's and 40's. As the identification of Carolina bays continued inland and into higher elevations, it lost favor. Today, bays are found on a continuum up to 200m elevation in the Carolinas, and the Atlantic has not visited those areas for over a million years.

    Douglas Johnson, in his 1942 book on the bays, made a statement that has been a guiding principle for me:
    Billings_Siberia.jpg
    Billings, Siberia, Russia from Google Earth
     
  10. Aug 6, 2011 #9
    Carolina Bays -Salt Tectonics?

    Is there any debate on whether these structures could be the reslt of salt tectonics? I did a google search for the Carolina Bays and any drilling activity, but a first search did not reveal anything significant. You think it would be easy enough to run a siesmic survey to see if there are any unusual changes in velocity, and try to correlate this to salt tectonic induced faulting. Or to run a gravity survey to detect any anomolies that could represent a bulb or stock or any sort of diaper, but there is not much available through simple google searches.

    Oil and mineral companies must not fund a whole lot of research into finding what is below the Carolina Bays, which are present from Deleware to Georgia. I am not 100% convinced about the impact theory without some real hard evidence to show that these bays are not salt tectonic structures, or soft-sediment deformation structures caused by a massive earthquake as a result of forces between the down going oceanic crust and the floating North American crust.
     
  11. Aug 18, 2011 #10
    I walked into the discount bookstore the otherday and found myself a like-new copy of the Roadside Geology to South Dakota. I never had much interest in glaciation, I bought the book to read about the Blackhills, however, looking at aerial photos and topo maps of glacial lakes/outwash I began to question my previous thoughts on the Carolina Bays.

    While imagining how these small lakes would form, a thought popped into my head: maybe the bays are area that small glaciers deformed the ground where small glaciers once sat. Perhaps the glaciation east of the Appalachians was less mature than what happened between the Appalachians and the Rockies. This would explain why there aren't eratics or moraines present in the area.

    So after doing a quick google search I found (and had suspected that hopefully) someone had beaten me to it.

    http://www.evolutionaryleaps.com/Reader_thinks_Carolina_Bays_have_glacial_origin.htm [Broken]

    If this idea has any merit to it takes away a lot of the luster of an impact origin, and should raise the issue of a sort of mutual evolution of the bays through both glacial cycles and hydrological cycles.
     
    Last edited by a moderator: May 5, 2017
  12. Aug 18, 2011 #11
  13. Aug 19, 2011 #12
    It has been considered here, but

     
  14. Aug 24, 2011 #13
    Thank you for the information Andre. I had to crack open my books to relearn some of these concepts like skewness.

    Until the recent East Coast earthquake I was unaware that earthquakes could be felt so far away from their epicenter. This is because East Coast rocks are not deformed to the point where they have been brecciated and heavily fractured. So they are extremely good conductors, they do not absorb kinetic energy as well as their West Coast brethren.

    Taking this information into account and some of the stories from the New Madrid earthquake of 1811 (sand volcanoes) I think earthquake induced soft sediment deformation leading to the formation of the Carolina Bays should be taken into question. Maybe this has something to do with the artesian wells theory, could you help me out Andre?


    Could a large earthquake 12,000 years ago have liquefacted underlying water laden sediments to form plumes leading to the formation of the Carolina Bays? I have seen truck-size ball and pillow structures but I admitt to never having seen such structures close to the size or extent of the Carolina Bays.
     
  15. Jul 11, 2012 #14
    Greetings: There were significant sightings of sand volcanoes (sand blows) in the Charleston vicinity after the 1886 quake. The concept is quite intriguing, when consideration is given to quakes substantially stronger over the last 200,000 years. Have a look at this page: Tehrkot Media Historical Imagery for a photo of a fresh blow in South Carolina.

    If earthquakes were involved, the timing constraint dictated by the lack of bay landforms on sandy surfaces created over the last 150,000 years remains, such as the Wando surface (see Soller, USGS Professional paper 1466-A, 1988). i.e., no "Carolina Bays" were created in 1886.

    The Carolina bay landforms in the Midlothian, VA, area, are sandy-rimed oval landforms resting on a gravel base. The local geology there would not support a sand blow geomorphology. Also challenging for a sand blow genesis are bays measuring over a few tens of meters across - of which there are significant quantities.

    - Michael
     
  16. Jul 15, 2012 #15
    The Firestone Younger Dryas paper alleges there is evidence of high temperature residue at the Carolina Bay elliptical marks which is similar to the high temperature residue that has found throughout the Northern Hemisphere that coincides in time with the occurrence of the Younger Dryas.

    The Firestone paper hypotheses that the Younger Dryas high temperature marks were caused by a comet that broke up and then struck the planet in multiple locations throughout the northern hemisphere. The comet hypothesis does not explain how the Younger Dryas event caused abrupt cooling of the planet for a 1000 years. (An impact event would cool the planet for 3 to 5 years, due to dust and sulfur dioxide after which it would return to warming.)

    As noted the Carolina Bay elliptical marks are significantly older (30,000 years to 60,000 years before present) than the Younger Dryas abrupt cooling event (the Younger Dryas event occurred 12,800 years before present.) There are roughly 1/2 million Carolina Bay marks. A comet could not cause 1/2 million marks on the planet.

    In the last 10 years, geomagnetic specialists have found evidence of cyclic geomagnetic excursions (during a geomagnetic excursion the geomagnetic field develops multiple poles and the field intensity drops by a factor of 3 to 10). A geomagnetic excursion is capable of abruptly cooling the planet by Svensmark's mechanism. (The cooling pattern during an excursion is complicated as there are multiple poles formed which causes both increases and decreases in galactic cosmic rays (GCR) depending on the location of new temporary pole.)

    There are geomagnetic excursions at the termination of the past interglacial periods and at the Younger Dryas.

    The Carolina marks are overlapping, elliptical, with an axis that is alligned in the North west direction.

    http://www.pnas.org/content/104/41/16016/suppl/DC1#F7

    Quote:
    Is the geodynamo process intrinsically unstable?

    http://eprints.whiterose.ac.uk/416/

     
  17. Jul 15, 2012 #16

    Dotini

    User Avatar
    Gold Member


    Thank you for a very interesting post.

    I agree that a reduction of the geomagnetic field could cause cooling via the Svensmark mechanism. But I'm not the sharpest tool in box, and fail to see the connection to Carolina Bays. Could you be bit more explicit about this, please?

    Respectfully yours,
    Steve
     
  18. Jul 15, 2012 #17
    Earlier research did not find any corrolation between paleo magnetic excursions and general atmospheric conditions.
     
  19. Jul 15, 2012 #18
    Hi Steve,
    Rather than starting with a conclusion and presenting the mechanism it is likely more effective to present the suite of observational anomalies and then present the mechanism. (i.e. The observational anomalies should logically support the mechanism.) It is seems that there are a suite of observational anomalies in three separate scientific fields that can be used to support the existence of a new mechanism.

    As the Firestone paper noted there is high temperature residue at multiple locations in both North America and Europe that coincides in time with the Younger Dryas abrupt cooling period (12,900 years before present). The Firestone researchers did not look for other observational evidence before formulating their hypothesis that an extraterrestrial impact caused the multiple burn marks on the planet’s surface.

    http://www.pnas.org/content/104/41/16016/suppl/DC1#F7

    The next two papers provide additional observational evidence that there is a cyclic event that abruptly changes the geomagnetic field and depending on the location of the strike can also cause volcanic activity.

    Monogenetic volcanoes do not share the same magma chamber and hence would not be expected to erupt at the same time. The fact that the five monogenetic volcanoes erupt at the same time and that they coincidentally capture the once in 30,000 to 100,000 year geomagnetic excursion supports the hypothesis that the physical cause of the geomagnetic excursion and the simultaneous eruptions is the same.

    http://www.agu.org/pubs/crossref/2006/2006GL027284.shtml
    The paper these researchers are discussing concerns archeomagnetic jerks. Archeomagnetic jerk is the term specialists have given to an abrupt 10 to 15 degree change in the inclination of the geomagnetic field. The jerk was found by analyzing ancient fired pottery such as tiles or sundials. The pottery is heated above the Curie temperature and hence when it cools captures the direction and field intensity of the geomagnetic field when it cools. The ancient tiles have the date and kiln owner written on the back of the tiles. The archeomagnetic jerks occur with a periodicity of roughly 400 years.

    http://geosci.uchicago.edu/~rtp1/BardPapers/responseCourtillotEPSL07.pdf
    So there is evidence of burn marks on the surface of the earth, cyclic significant changes to the geomagnetic field (archeomagnetic jerks), and cyclic very large geomagnetic changes -geomagnetic excursions.

    There are a couple of dozen additional geophysical papers that provide additional support for the assertion that something is forcing the geomagnetic field and that what forces the geomagnetic field occasionally causes volcanic eruptions. The geophysical papers in question are interesting in that they support the assertion that there is a cyclic forcing event but do not help with understanding the fundamental mechanism.

    The Researchers in the above paper speculate that a solar process could be the physical cause of the geomagnetic anomalies. The next step is to look for astronomical observations to see if there is support for a hypothesis that there is a cyclic solar change that is causing the geomagnetic changes and to see if the observations can be used to define the mechanism.

    If you are interested I can outline the next set of observations in the astrophysics section of this forum, later this year.
     
  20. Jul 15, 2012 #19
    Hi Andre,

    The paper you quote was written in 1997 which is prior to the discovery of and confirmation that there are archeomagnetic jerks. Below is a paper that notes there is a 100k year pseudo cycle in the geomagnetic field intensity. There is also a pseudo 41 k year cycle in the geomagnetic field. Other researchers have, however, noted that the orbital parameters are not not physically capable of causing sufficient changes to the liquid core to cause the “geomagnetic dynamo” to initiate an excursion or to cause an increase the geomagnetic field intensity. Another theory proposed to explain the geomagnetic excursions conceding with the termination of the interglacial period is ice sheet build up cause a geomagnetic excursion and ice sheet melting causes changes to the "dynamo" to increase the intensity of the geomagnetic field. That hypothesis fails as the geomagnetic intensity increases thousands of years before the ice sheet melting and as others have noted the geomagnetic excursion occurs at the termination of the interglacial period prior to the ice sheet build up. (The ice sheet affecting dynamo hypothesis does not explain the Younger Dryas period which occurred during the initiation of the interglacial period.) There is a problem with cause and effect.

    Archeomagnetic jerks are likely not caused by orbital parameters affecting the “geomagnetic dynamo”. (the archeomagnetic jerks are too rapid and too frequent). The archeomagnetic jerks appear to be a paradox, something that cannot be explained by the assumed mechanism. There is evidence of burn marks on the surface of the earth. The burn marks have been dated to 12900 years which coincides with the Younger Dryas abrupt climate event. There is evidence of a geomagnetic excursion at the time of the Younger Dryas and at the termination of glacial periods and interglacial periods.

    http://www.pnas.org/content/104/41/16016/suppl/DC1#F7

    I have as noted above been looking through astronomical papers looking for observational evidence to explain what is observed. What I have found appear to be interesting. I will take a crack at presenting the astronomical observations late this year.

    At this time, I have not further comments concerning the geomagnetic field or the burn marks.

    http://www.geo.uu.nl/~forth/people/Hirokuni/Hiro2002a.pdf

     
  21. Jul 19, 2012 #20
    Thanks, I have to read up on my paleomagnetics, I see. We're quite of thread now away from the Carolina bays, but on the excursions maybe google Gary Glatzmaier
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Carolina Bays
Loading...