On Thursday, copper mining stocks experienced broad declines. Southern Copper Corp (SCCO.US) fell nearly 7%, Ero Copper (ERO.US) dropped over 6%, Taseko Mines (TGB.US) declined 5%, and Hudbay Minerals (HBM.US) slid more than 4%. The movement follows a 1.78% intraday drop in the main continuous London copper contract.