Material is transferred from the earth’s mantle to the
at diverging boundaries of the the earth’s tectonic plates
(for example the Mid-Atlantic Ridge). Deposition of surface rock occurs where continental
converge (for example India and Asia). The energy for tectonic plate movement and
heating of the mantle comes from the earth’s core.
Surface rocks are eroded by precipitation, heat, frost, wind and waves –
mostly driven by energy from the sun, with some tidal erosion due to the gravitational
force of the Moon. The eroded material may eventually become sedimentary rock such
as sandstone, or combine with organic material
to form soil.
Solar energy enables plant organisms of the biosphere
to use soil, water and gases to grow and provide food for other lifeforms. Material
is generally returned to land or ocean bed when organisms die [Note
1]. Skeletal remains may eventually form part of sedimentary rocks such as
Rock material is ultimately returned to the mantle in tectonic plate subduction
(for example the Pacific coastline of the Americas), but loose soil and material is
retained near the surface. Rock, ash, water and gases are emitted from volcanoes in
Note 1: An exception to this is people who pay
to have their remains blasted into "space" (above 50 miles by one definition).
The late "Scotty" from Star Trek and others who were rocketed into "space"
recently disappointingly only achieved earth orbit. Eventually their ashes will probably
return to earth - in the meantime will the ashes affect global warming? Is this an
environmetally responsible procedure?
(This was written soon after the launch, however it was reported in August 2008
that the launch failed - thus some of Scotty's remains have already been scattered
on earth rather expensively, in money and environmental damage terms. Undeterred,
another attempt is to be made to propel more of Scotty's remains into space - the
same questions apply!)
If you have an original explanation of "how the world works / recycles"
send it in and I may include it on this page (200 words maximum please)