Production at the mine has slowed while the longwall plow mines through a sandstone intrusion into the coal seam. The sandstone intrusion is a continuation of the same geology that slowed production in August last year.
“Safety of our employees is our first priority. While disappointed to find the same geologic condition in the current section of the mine as the previous section, the discovery provides useful information on the fault direction and slope for use in our mine planning for the rest of 2008 and the future," Cliffs chief executive Joseph Carrabba said.
The company said the fault area accounts for approximately 1200ft of the 10,000ft coal section being mined.
“We estimate that we are currently 25 percent through the fault area and our North American Coal team is diligently working to move the plow forward through this difficult mining,” Carrabba said.
“At this time, we believe we will be in difficult mining for 60 to 90 days."