SANTIAGO Aug 31 A Chilean union that represents copper mine workers on Monday rejected a move to drastically cut staff at the El Abra mine owned by Freeport-McMoRan and was considering action after 700 workers had their jobs terminated at the weekend.
Analyze the relationship between 'El Abra mine' and 'copper' within the context of the input sentence.
Options: manufacturer, distribution format, product/material produced, location of formation