Share this credible answer with others. Simply paste this code into your blog or Web page:
Precambrian rocks are mostly covered by rock systems of more recent origin, but where visible they commonly display evidence of having been altered by intense metamorphism. Precambrian rocks often occur in shields, which are large areas of relatively low elevation that form parts of continental masses.
|
Answer verified with
|
HighBeam gives you access to newspaper, magazine, and trade journal articles plus press releases, facts, information, and biographies from thousands of sources.