Opened in the 1950s, the company’s Blackhead Quarry, located at Blackhead on the seaward side of Green Island, produces 300,000 tonnes per year. The company also operates quarries at Logan Point, in Dunedin and Balclutha as well as the Walton Park sand plant in Fairfield. The Balclutha quarry, located approximately 80km south-west of Dunedin, is …