"The longwall section was under a K-order for most of October 31 through most of November 2," Arch Coal's Kim Link said.

"MSHA completed its analysis of the incident, and gave Sufco the green light to resume operation of the longwall on Friday afternoon."

The order was issued following a "minor floor heave" at the mine's longwall early Wednesday local time that resulted in both rib failure and an accumulation of coal at the tailgate.

According to various media reports, the bump scored a magnitude reading of 2.8 at the nearby University of Utah's seismology stations.

A company spokesperson told International Longwall News nobody was injured and no equipment damaged in the incident.

No workers at the 300-employee operation lost work as a result of the incident.