Where did you get this information? I have never heard such a thing.
"Before 50 million years ago, Earth had no regular ice ages, but when we did have them they tended to be colossal. A massive freezing occurred abut 2.2 billion years ago, followed by a billion years or so of warmth. Then there was another ice age even larger than the first - so large that some scientists are now referring to the age in which it occurred as the Cryogenian, or super ice age. The condition is more popularly known as Snowball Earth.
" 'Snowball,' however, barely captures the murderousness of conditions. The theory is that because of a fall in solar radiation of about 6 percent and a dropoff in the production (or retention) of greenhouse gases, Earth essentially lost its ability to hold on to its heart. It became a kind of all-over Antarctica. Temperatures plunged by as much as 80 degrees Fahrenheit. The entire surface of the planet may have frozen solid, with ocean ice up to half a mile thick at higher latitudes and tens of yards thick even in the tropics."