Re: Hypothesis Involving Planetoid Impacts

"Professor Gauss" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Not being a geologist, I am new to this group, but have a hypothesis and I
was
> wondering if it has been discussed yet by geologists, either here or
elsewhere.
>  Here is the hypothesis:
>
> 1) The early earth was smaller than it is now.  It had a crust floating on
top
> of a mantle which covered the entire earth.  The crust formed following an
> extended period of chemical reactions at the earth's surface.  A possible
> example of such a reaction is the hydration of minerals caused by the
> absorption of water from the atmosphere.
>
> 2) Large planetoids impacted the earth.  The ejecta from one or more of
these
> collisions coalesced to form the moon.  (This idea is not new.)  A large
> quantity of material was also added to the earth's mantle and/or core.
This
> caused the earth's volume to increase by a factor of about 5.  The crust
was
> now distributed over a larger surface area.  Although land now comprises
about
> 29% of the earth's surface, inclusion of continental shelf areas would
> correspond to a higher percentage, let's say 35%.  This would cause the
radius
> of the earth to increase by about 70%.
>
> 3) The relatively highly curved crust relieved itself on the now less
highly
> curved surface by distorting.  Massive cracks may have given rise to long
> rivers such as the Mississippi.  In other places, more stress relief may
have
> caused the formation of wrinkling and faulting to produce various types of
> mountain ranges.  The cracking process, in addition to the impacts
themselves,
> may have caused the crust to break up into continents.
>
> I know that this hypothesis sounds far-fetched, especially considering the
vast
> amount of material that needed to be added to the earth's mass without
> completely destroying it.  But isn't it plausible that high-density
meteorites
> could have penetrated the crust and gravitated toward the earth's center,
while
> the punctured crust floated back up to the surface?  If there are links to
> refutations of such ideas on the web, I would appreciate knowing about
them.
> Thank you for your consideration of this matter.
> --
> To hear is to forget,
> To see is to remember,
> To do is to understand.
> -- Ancient Chinese proverb

You are correct.  You are not a geologist, and don't have a clue.