| 21. | At its peak, the city of open-pit mines in the world.
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| 22. | The open pit mine has operated over historic underground gold mine workings since 1988.
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| 23. | The Cullinan kimberlite was discovered in 1902 and in 1903 open pit mining commenced.
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| 24. | Like the Robinson mine, it is an open pit mine and produces copper.
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| 25. | Tracks were laid through the open-pit mine, with the length varying.
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| 26. | Mason and Barry switched from tunnel mining to open-pit mining in 1867.
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| 27. | The is an open-pit mine in Hachinohe, Aomori Prefecture, Japan.
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| 28. | Troilus is a new open-pit mine in Quebec that began production in January.
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| 29. | The Paroo Station lead carbonate open pit mine is located 30 kilometres west of Wiluna.
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| 30. | Both have been open-pit mines.
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