I wrote: Subduction is largely vertical. Sliding is primarily horizontal.
Webo replied: "Largely" and "primarily" indicate the possibility of an overlap of concept here. I'm curious if other detractors of subduction agree with your definition? If so, then I have been arguing in vain for all these pages [mostly on the expanding earth thread], because it matters not to me how much vertical or horizontal is involved in the concept. If "horizontal sliding over/under" is the agreed upon plate movement, then I have some basic questions about mountain formation in this view. If "vertical", then I still plead compression zone with or without the standard "subduction."
* My understanding of tectonics comes mostly from Cardona [at
http://thunderbolts.info/forum/phpBB3/v ... =10&t=3824], Shock Dynamics [at
http://newgeology.us] and Tassos material [at
http://michaelnetzer.com/gu/index.php?o ... &Itemid=72,
http://www.scientificexploration.org/jo ... tassos.pdf etc]. They may not all be compatible, but so far they seem to be sufficiently so.
* Shock Dynamics seems to explain best how the sliding occurred and it suggests that an impact initiated the supercontinent breakup and the sliding of the pieces over the Moho layer.
* Cardona adds that sudden braking of Earth's rotation during Saturn flares could also have initiated sliding.
* The sliding would have been largely horizontal, but the sliding pieces could have encountered slopes, like the Pacific Ocean ridge, that they may have slid over with some slight vertical motion, but still mostly horizontal.
* Cardona said the Earth would have been heated up during Saturn flares, due to falling detritus, including burning hydrocarbons, and due to friction of sliding continents.
* Shock Dynamics said friction was almost zero during most of the sliding, but friction would have been highest at the beginning of the sliding, when the impact was overcoming continental inertia, and at the end of the sliding, as the continents slowed down below a critical level, at which friction would have increased rapidly until the continental movement halted. Those points were on the leading and trailing edges of the continents, where mountains built up, with the highest ones building up at the leading edges as continents slowed down, such as the Rockies and Andes.
* So the Pacific Ring of Fire is the area where the continents built up lots of friction and heat that has still not entirely cooled down to ambient temperature, so volcanoes and earthquakes still occur there.
* The seafloor that the continents were sliding over would resemble subduction on the leading edges of those continents, but the mechanism is considerably different. I'll just quote the site to try to explain this.
The giant meteorite explodes, penetrating the continental crust. ... The force pushes up low mountains, and the landmass slides away like a ship on water, fluidizing the contact layer. Behind the landmass, a surface layer of oceanic crust is melting and cooling to form the mid-ocean spreading ridge with transform faults, pulled open by the landmass.
When the leading edge loses enough energy, the contact layer at the leading edge solidifies. The momentum of the landmass carries it forward like a car hitting a wall, piling up high mountains. The formerly fluidized contact layer in front (gray line) is a Benioff zone, called subduction zones in Plate Tectonics.
* The low mountains on the left would be the Appalachians and the high ones on the right the Rockies, where the subduction-like area exists.
