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Apuntes

. . . . . . . . . . . . . . CHAPTER 7 The Viburnum Trend Underground-An Overview Jon Cacmack,* Bob Dunn,* Michael Flach,* and Greg Sutton* 7.1 INTRODUCTION The Viburnum Trend is a world-class lead, zinc, and copper ore body located in southeast Missouri, USA (Figure 7.1). The ore trend is approximately 64 km (40 miles) long by an average of 152 m (500 ft) wide. Ore thickness runs from less than 3 m (10 ft) to over 30.5 m (100 ft), with an average around 12 m (40 ft). Average depth of the ore body is 0.3 km (1000 ft). Originally, in- place mineral resources were in the neighborhood of 450 million tonnes (500 million tons). During the past 40 years, five different companies have operated 11 different mines within the trend. Today, this number has dropped to eight mines and one company: SEMO Mining and Milling Division of the Doe Run Resources Corporation. Presently (as of April 1, 2000), SEMO employs approximately 890 people at eight different under- ground mines, six mills, and various support offices. This chapter discusses the current practices and some unique aspects of the Viburnum Trend underground mines. 7.2 SAFETY ...