"To see what is in front of one's nose needs constant struggle." (~ George Orwell)
Oblate planet - equatorial rupture - circular breakthrough
Essential shapes
Solid body
Using a different illustration to emphasise the connectedness of the principle elements describing expansion and symmetry with Earth rotation in the previous post :-
1. Planetary oblateness
2. Equatorial rupture
3. Indonesian breakout
The symmetry of these elements in relation to the Earth's rotational axis reflect the importance of rotation in steering expansion, i.e., the changing oblateness of the Earth, equatorial rupture, and mantle breakout opposite the hinge of dilation.
The zone of elevation encircling the Pacific and extending to the Mediterranean is the perched remnant of an ancient plateau that is being eroded to form the mountains we see today. The general lobate structures of the belt reflect gravitational collapse. So do the folds in it, which are a direct consequence of the instability of changing Pangaean Earth curvature.
The central circle is the roof of the red Pacific bubble in the previous post. Combined, the equatorial split and the bubble represent Pacific breakthrough ('Panthalassa' and the 'Tethys').
(Further expanatory notes are on the site referenced in the header.)
[ See also - Debunking Plate Tectonics - at :-
http://www.platetectonicsbiglie.blogspot.com/
A new world opens up ... marvellous! Here's one question: "The general lobate structures of the belt reflect gravitational collapse." Why do you think do lobate structures (or loopy shapes) indicate gravitational collapse?
ReplyDeleteBecause of the curvature difference of the Earth as it used to be, becoming as it is now. You could imagine the configurational dynamics represented by a smaller sphere emerging through a larger one (the small sphere being the old Earth and the bigger one being the new one). The intersection between the two is marked by a circle, which is the locus of the biggest curvature difference, which is where there would be most 'run-off' (if we were thinking water at equilibrium on a round Earth). It's also where there would be most crustal instability (collapse). The deformation affecting the small sphere has therefore spherical ('flat') elements - which controls the way that the whole of the Western Pacific has swivelled open. The series of loops westwards from the Big Indonesian Bubble marks the hinge of Pacific dilation (and incipient mantle breakthrough (Black, Caspian and Western Mediterranean Seas). The loopiness is more intense, but smaller scale. Going east from the bubble (the scissoring-open Americas) the loopiness has dissipated altogether (Alaskan loop is the ripped off eastern edge of the bubble). Lobateness is linked to the big ruptures of the Owen Fracture Zone and the next parallel one marking the cusp between the Himalayas and the Indonesian Loop - that bit through China where they have such terrible trouble with big earthquakes. I think these big rifts could be old, .. very old.
ReplyDeleteDon, I'm sorry, I don't get it. The words are a little difficult. Oblateness, lobateness, I'm lost.
ReplyDelete"You could imagine the configurational dynamics represented by a smaller sphere emerging through a larger one (the small sphere being the old Earth and the bigger one being the new one). The intersection between the two is marked by a circle, which is the locus of the biggest curvature difference"
Not sure I get that either. If there is an intersection, then it's the mantle pushing through the old Earth. I'd expect rifts, not necessarily lobate ones. Googling images for "lobate", you'll find images from the Moon and Mercury with articles claiming they are, in fact, shrinking.
My confusion is complete. :-)
Oblateness. I'm not really sure how people use it mostly. I use it to mean that the Earth is bigger round the middle (equator). The 'flatter at the poles' drops out of the picture since the geology focusses the dynamics around the equator.
ReplyDelete*Old Earth and New Earth*. My Goodness! My bad wording right enough!! Sorry for the confusion. It seems really odd to me too, reading it now. Basically I just meant that the mantle pushing through the crust makes a circular intersection. Virtually all aspects of deformation we see in the the continental crust we have today is 'fossilised' since Mesozoic times = the sum of all deformation up until breakthrough of the mantle (ocean floors) (The 'Arrow' of geological time, .. no repetition, no cycling. The deformation since the Mesozoic has all shifted to the oceans.
How that circular intersection is expressed is quite complicated, now that you've asked the question. It's expression in the crust (old crust) is the Indonesian Arc and the teased-out 'swivellings' at the crust/mantle interface making up the Western Pacific Margin as far north as the Russian Peninsula (Fig.6 in this post):-
http://earthexpansion.blogspot.com/2011/07/earth-expansion-pacific-breakthrough.html
Its expression in the mantle is the Indian - Pacific spreading ridge grown out from under the crust. That's the rift you would expect to see. It's just grown big. The mountain belt in the crust and the mountain belt (spreading ridge) in the mantle are the same thing, just offset a bit by global extension according to that megaboudinage principle I mentioned once(Figs.7-9 same link) (I see I can't count in the numbering there). :-)
*Lobate shapes* That Indonesian circularity is the biggest lobate shape of all and the most perfectly formed, albeit disrupted. It marks the crest of mantle breakthrough (the 'bubble'). Either side of it though is the latitudinal split, which also has 'bubbly' tendencies in the upper crust in response to mantle breakthrough , particularly on the western side, and the crust sloughing off that makes less 'circular' (more "loopy") shapes (Alps, Carpathians, Suleimans. (The Eastern side remained more or less straight; no loops except maybe Peru).
It's really mindboggling to get your mind on to the scale of all this. You are not alone. I was, once, too, .. similarly boggled. Which is why I'm persisting with it. The way it alters the whole perception of global dynamics as it relates to the geology is worth making a point of.
"Oblateness. I'm not really sure how people use it mostly. I use it to mean that the Earth is bigger round the middle (equator). The 'flatter at the poles' drops out of the picture since the geology focusses the dynamics around the equator."
ReplyDeleteOkay :-) But note that *oblate* does mean *flattened*, regardless of how people might use it mostly. Which is why *equatorial oblateness* (in another of your blog postings) evokes a rugby ball poised on the tip. Which is not what we're dealing with in the case of the Earth. And you're saying that in former times the Earth's oblateness was more marked than today. Well illustrated here:
http://en.wikipedia.org/wiki/Oblate_spheroid
Circular intersection, that's very clear.
"The mountain belt in the crust and the mountain belt (spreading ridge) in the mantle are the same thing, just offset a bit by global extension [...]"
Okay :-) But you said the mountain belt in the crust was due to gravitational collapse, indicative of the older Pangaean crust which was more strongly curved, especially at the equator, adapting its curvature to the bigger sphere developing underneath, so flattening out, with the excess equatorial vaultedness forming high plateaus slated to collapse under gravity to what we see today as mountains. Whereas the spreading ridge, on the other hand, does not have quite the same story. So I'm not sure under what angle you're seeing them as the same thing.
Lobate shapes. Yes, I can see them in the Western Pacific on Google Earth. How could you miss them, once you start seeing them?
Actually, .. I guess it's more of an oval intersection, but the difference is minimal.
ReplyDelete*Collapse under gravity*
Two ways, 1. erosion at the surface, and 2. Slipping about at the base of the crust with the overlying stratigraphy eventually 'falling over' (and because it's being eroded, this 'falling over' is eventually exposed as folding. The more the erosion, the more the older units are exhumed (Proterozoic / Archaean).
*Mountain belts and spreading ridges are the same thing*
One in the crust, the other in the oceans, but be careful, .. there's two scenarios, the Pacific (older) and the Atlantic (younger). In Plate-speak the Pacific is 'active' (meaning there is all this subduction, .. and mountain belt collision). The Atlantic is 'passive' meaning there isn't any of either. Was there once and did it stop? No, .. the continental margins are different (circumPacific - type structure and volcanism are absent). They're also different in other ways (Earth expansion)- Pacific structure is forceful intrusion on a circular breakthrough with peripheral splits (and was equatorial / latitudinal), as the crust was *pushed* apart. Atlantic breakthrough was passive mantle 'gap-filling' in response to longitudinal breakthrough as the crust was *pulled* apart. The 'Pacific mountain belt' is the same uplift, described by the crust *and* the mantle together, one above the other, but the two became offset as the mantle split grew out from under the crustal 'uplift' (equatorial zone = oblateness) to form the spreading ridge of the Pacific we see today, leaving the Pangaean equatorial zne 'fossilised' in its wake, .. and cllapsing as growth took over in the mantle. (= Earth rotational adjustment : hemispheres swivelling open) (Flat dislocations in the crust are largely unrecognised because they tend to be filled with sediments (as basins) are 'de rigeur / par for the course / and largely operative since the Mesozoic (so we don't see them) (Cenozoic floors). Forceful breakthrough is related to change of oblateness and mantle growth - and was tremendously rapid in the beginning (American scissoring; with its mirror-image west of the bubble ; largely failed - but still 'struggling' (all those earthquakes; Fig.1 here)
http://earthexpansion.blogspot.com/2011/03/japan-earthquake-march-2011.html
(Lobate shapes : trace them west from Indonesia through the Himalayas to the Carpathians and the Alps - as big collapse structures. e.g. Pakistan.)
http://users.indigo.net.au/don/to/irancollapse.html
(PS. but no, .. no 'rugby balls'. just oblate spheroids).
Thanks, Don. I still don't get how "mountain belts and spreading ridges are the same thing", but I can understand it later, some things just take time.
ReplyDelete"[...] the mantle split grew out from under the crustal 'uplift' (equatorial zone = oblateness) to form the spreading ridge of the Pacific we see today [...]"
Okay, but really, for oblateness, take a look:
http://www.thefreedictionary.com/oblate
"Having an equatorial diameter greater than the distance between poles; compressed along or flattened at the poles: Planet Earth is an oblate solid."
It is misunderstandable for me to talk about "equatorial zone = oblateness" when the equator is clearly the zone where the Pangaean Earth does *not* show the oblateness; it is at the poles, not at the equator. The Earth is oblate and the oblateness can be seen at the poles. On an oblate Earth as we represent it, the equatorial zone is protrudent.
*About the mountain belt and the spreading ridge being the same thing*
ReplyDeleteRelative to the *Present* equator the Pangaean equator is displaced some 40 degrees north (where the fold belt (/belt of elevation) is) by the asymmetry caused by mantle breakout around Antarctica. If we look at the Earth from Antarctica we can see the amount of mantle emplacement (/ocean) is almost as big as the Pacific. That's the spreading that shifted the continents northwards (Wegener's 'flight from the pole') 40 degrees away from the equator. Or, ..the 'bottom fell out of the Earth'. (Prolapsed) (but not prolate). The recognition of the circumglobal fold belt as the *Pangean equatorial zone* follows, not from it being a fold belt or a belt of elevation, but from the general global symmetry either side of it described by its axial rupture combined with the swivelling that has affected those hemispheres being symmetrically configured with the Earth's rotation. THEN we can deduce that circumglobal zone of elevation and collapse folding to be an expression of 'equatorialness'. THEN say earlier equatorialness was a zone of blateness (because the present Earth's equatorial zone is oblate). Then say that the disturbance was also a zone of equatorial oblateness (related to mantle breakthrough).
The present-day equatorial zone is not a zone of folding or of elevation (because by definition elevation is defined by relation to water level) but it is slightly oblate (bulgy round the middle = oblate spheroid) and does show a global symmetry of deformation (albeit much weaker than the earlier one) about the Atlantic equatorial region = the offset of the ridge on the transform faults (southern hemisphere east /northern hemisphere west) .. and in the Pacific by the Indonesian- Solomons displacement of the Western Pacific margin.
So what we're saying is : 1. Two equatorial zones, and 2. the earlier one *much* more deformed than the later one (and all related to oblateness and that bubble of Indonesian circular mantle breakthrough, strung out along the western Pacific. Which would appear to be the first deformation to happen. Two zones were originally the same thing, with the offset reflecting the effects of massive mantle breakout.
They are "both the same thing", because both originated as circumglobal uplifts, originally vertically configured (mantle below crust), but the mantle uplift (Pacific) has grown out from underneath its original location below the Pangaean crustal uplift of the Alps-Himalayas - Cordilleras. The original coincidence is still present in the Persian Gulf - Red Sea - Mediterranean region. Thre are also expressions of it in the Galapagos Rift and the failed rift of the Azores - Biscay Rise
Some would no doubt say that the argument is a bit circular, but that's because the full suite of observations that builds this picture leaves nothing much for an independent test. Everything to test it is used to build it. If it *were* a 'hypothesis', (magicked from the outset somehow according to the American Way of hypothesising) then all those facts to build it could be used to test it. As it is, they're all in there already. In Fig.2 here
http://earthexpansion.blogspot.com/2011/02/earth-expansion-synoptic-simplicity.html
the original equatorial bulge is around the zone of the lip of those grey hemispheres (the belt of Earthquakes). The coincident zone of collapse folding is a result of that oblate curvature being no longer stable in the changing curvature of the growing Earth (red in the figure). (And of course as a topographic high it is also a special zone of erosion). Both the folding and the erosion are gravitationally reducing the original equatorial periphery of those grey hemispheres(the north and south topographic bands in Fig.1) to flatness.
Phew! How did I go? :-)
About the oblateness:
ReplyDeleteSorry, I got it wrong! Got it wrong saying that on an oblate spheroid such as our Earth (and more so the old Earth as you describe it) oblateness could be observed at the poles. I think it is equally imprecise to talk about polar oblateness as to talk about equatorial oblateness. In fact, "oblateness" refers to the entire spheroid, not to its polar or equatorial aspects - even though you'll find uses for both:
http://www.google.com/search?q="equatorial+oblateness"
http://www.google.com/search?q="polar+oblateness"
We both agree it's bulging around the middle and flattened at the poles. And I'll probably remain the only person on this planet ever to have taken issue with that wording. I know what you mean, and others will, too; all settled now, sorry for the noise. :-)
About the circumglobal fold belt as the Pangaean equatorial zone: great comment, almost a new article!
About mountain belts and spreading ridges being the same thing:
They are "both the same thing", because both originated as circumglobal uplifts, originally vertically configured (mantle below crust), but the mantle uplift (Pacific) has grown out from underneath its original location below the Pangaean crustal uplift of the Alps-Himalayas - Cordilleras. The original coincidence is still present in the Persian Gulf - Red Sea - Mediterranean region.
Great, got it!
Thre are also expressions of it in the Galapagos Rift and the failed rift of the Azores - Biscay Rise
http://maps.google.com/maps?ll=-1,-91&t=h&z=5
http://maps.google.com/maps?ll=38,-29&z=5&t=h
You mean spreading ridges rising so high they become visible as mountains above sea-level?
*Oblate*
ReplyDeleteYes I made a similar note, but deleted it as it put the post over Google's limit, and knew we were saying pretty much the same thing. I guess the terminology is imprecise as you say. :-)) "Equatorial bulge", and "polar flattening" would be better as you say. (Saying the same thing and getting wires crossed - how can that be? :-))
*The same thing*
I still managed to botch it there too, .. but it seemd to work.. The mantle and the crust lift together, but the crust slips off. Back to the Future in other words (vertical tectonics as it was before the plate spinning Pt-eromancy of the "New Global Tectonics " (The hat-magic of how geophysics sees geology.)
(Real good fun this.. Thanks for joining in.)
*Google Maps*
Actually I'm not big on Google maps for viewing the Earth, preferring to use the basic Google Earth, but no problem. Anybody reading this might care to know you can cut and paste those comma-separated numbers directly in to the Fly-to window of GE and it takes you right to the spot. GM seems to be a bit better for street view?
*Spreading ridges and sea level*
No, Somehow they don't get above sea level except as volcanoes here and there (particularly in the initial opening (especially Western Pacific Guyots) The only place the ridge itself seems to have been above sea level recently is the Azores (volcanoes) (and Iceland of course - more volcanoes). That's one of the conundrums for Plate Tectonics (and for expansion as well). There's lots of little wimply pimples in parts around the ridges, but the bigger volcanoes are never on the ridge, but on the cross-faults. It seems to be that the water is 'of the mantle', and is the equilibrium 'plimsol line' to which the internal pressure of the Earth is pushing. That's the level mostly aspired to by mantle volcanoes (guyots, and the level that the crust on top of them will collapse to (by collapse and erosion). Crustal correction of course takes time, where that of water is literally immediate. Water and mantle are being manufactured together, .. by-products of expansion. It's the way I see it anyhow (for now).