bedrock vs ore

bedrock

noun
  • The solid rock that exists at some depth below the ground surface. Bedrock is rock "in place", as opposed to material that has been transported from another location by weathering and erosion. 

  • A basis or foundation. 

verb
  • To establish on a solid foundation. 

ore

noun
  • Rock or other material that contains valuable or utilitarian materials; primarily a rock containing metals or gems for which it is typically mined and processed. 

How often have the words bedrock and ore occurred in a corpus of books? (source: Google Ngram Viewer )