CLC: Meteorite from Ceres
The continental granites are what's left of a huge meteorite.It's hard to imagine how something that large could have impacted the Earth so slightly as to leave a skid mark, without simply blowing the whole planet apart. A possible solution is that something first impacted a planet between Mars and Jupiter, blowing it apart, and thereby creating the asteroid belt, and losing enough velocity in the process that the subsequent impact with the Earth was very gentle.
