This process supposedly started 650 million years ago when all the worlds' land masses
were grouped together in a supercontinent positioned near the equator and runaway
"weathering" took massive amounts of CO2 out of the atmosphere and hence lowered
the earths' temperature so that massive ice sheets formed and extended from both
poles towards the equator eventually covering the whole globe.
Supposedly the earth was an ice covered snowball like this for another 25 million years
until vulcanism eventually reversed this situation and the green house gases produced
melted most of the ice and raised the earths' temperature again.
I am assuming that vulcanism has been ongoing since the earth formed.
If so then there seems to be a big problem with this theory.
Surely vulcanism around the planet would have always been pumping more CO2
and other greenhouse gases into the atmosphere so this would have counteracted
any effects of weathering out of CO2. I can't then see how any snowball earth process could
have gotten started let alone lasting 25 million years ( again no vulcanism ?).
Drop stones are another point in question here. People assume that because these
things are found in deserts that they point to transport by glaciers dating back
to snowball earth but the truth is they could have been depossitted by glaciers
from any ice age in the past. I am informed the earth has ice ages around
every 100,000 years which gives us a few to choose from.
Interested in what others think about the snowball earth idea.
were grouped together in a supercontinent positioned near the equator and runaway
"weathering" took massive amounts of CO2 out of the atmosphere and hence lowered
the earths' temperature so that massive ice sheets formed and extended from both
poles towards the equator eventually covering the whole globe.
Supposedly the earth was an ice covered snowball like this for another 25 million years
until vulcanism eventually reversed this situation and the green house gases produced
melted most of the ice and raised the earths' temperature again.
I am assuming that vulcanism has been ongoing since the earth formed.
If so then there seems to be a big problem with this theory.
Surely vulcanism around the planet would have always been pumping more CO2
and other greenhouse gases into the atmosphere so this would have counteracted
any effects of weathering out of CO2. I can't then see how any snowball earth process could
have gotten started let alone lasting 25 million years ( again no vulcanism ?).
Drop stones are another point in question here. People assume that because these
things are found in deserts that they point to transport by glaciers dating back
to snowball earth but the truth is they could have been depossitted by glaciers
from any ice age in the past. I am informed the earth has ice ages around
every 100,000 years which gives us a few to choose from.
Interested in what others think about the snowball earth idea.