- Jim-歸鄉樂Lv 76 years agoFavorite Answer
We think it's from the incorporation of very hot radio active elements.
They are out there floating in space as the earth accretes, it includes some of this ferociously hot material, as it gets inside there it begins to heat up the rocks around it, and if you build the earth fast enough and you incorporate enough of this really hot radio active elements, it will be enough the melt the earth from the inside out.
It's cooling from the outside in, so from the outside it begins to crust over, I think it's this little scab like in the wound of cool rock but still very hot and then gradually begins to cool from the outside in.
2014-08-15 08:25:21 補充：
更正"it will be enough to melt the earth from the inside out才對,the改成to我打的太快啦.Source(s): jim
- BethLv 76 years ago
We think it's from the incorporation of very hot radio-active elements.