gold mine vs storehouse

gold mine

noun
  • A plentiful stockpile of something sought after. 

  • A mine for gold ore or metal. 

  • A very profitable economic venture. 

storehouse

noun
  • A single location or resource where a large quantity of something can be found. 

  • A building for keeping goods of any kind, especially provisions. 

verb
  • To lay up in store. 

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