US Mine Safety and Health Administration spokeswoman Amy Louviere confirmed the event to International Longwall News, stating the worker was taken to a hospital but then released to go back to work.
Rock surrounding the 4 West Longwall section was dislodged in the event, causing the worker's injuries.
The mine is also now under a 103k order by MSHA pending its investigation, she added.
A request for comment from UtahAmerican owner Murray Energy was not returned by press time.
Utah Seismograph Stations director Walter Arabasz told the Salt Lake Tribune that a seismic event measuring 2.0 was recorded at 8.19am, just 15 minutes prior to the 8.39am timestamp given to the worker's incident. Another measuring 1.7 was measured six hours prior, and the origins of both were consistent with West Ridge's location.
