Re: Why is 70% of Earth's sial missing?

On Mar 26, 10:55 pm, Andrew Nowicki <and...@xxxxxxxxxx> wrote:
The Earth's crust is made of two layers called
sima and sial. Sima is the lower and denser layer.
It is 5 to 10 km thick and covers the entire surface
of the Earth. Sial is 20-70 km thick and covers only
30% of the Earth's surface; this is the elevated
part of the Earth's surface called continents. The
remaining 70% of the Earth's surface is covered with
oceans. None of the existing theories explain how the
sial was selectively scooped up from 70% of the Earth's
surface and deposited on the proto-Moon.

Fresh sima (magnesium-iron silicate) and sial
(aluminum silicate, clay) are produced at midocean volcanoes:
http://www.asu.edu/clas/csss/csss/News/life.html
Unlike sima, sial (aluminum silicate, clay) does not
precipitate at the midocean volcanoe (residual negative
charge prevents clumping), but is propelled toward the
continent by the waves. On shore it settles out as
clay, feldspar or anorthosite (lunar highlands).
When Earth's oceans evaporate, clay and mud, which
line portions of the seafloor, will create the appearance
of sial also dominating Earth's crust. John Curtis


.

Relevant Pages

  • Re: Why is 70% of Earths sial missing?
    ... Sima is the lower and denser layer. ... It is 5 to 10 km thick and covers the entire surface ... oceans. ...
    (sci.astro)
  • Why is 70% of Earths sial missing?
    ... The Earth's crust is made of two layers called ... Sima is the lower and denser layer. ... It is 5 to 10 km thick and covers the entire surface ...
    (sci.astro)
  • Re: Why is 70% of Earths sial missing?
    ... Sima is the lower and denser layer. ... It is 5 to 10 km thick and covers the entire surface ... First, for anyone else reading this, "sima" refers to rock ... were continents and oceans, maybe there weren't. ...
    (sci.astro)