CHARLESTON, W.Va. -- The federal Mine Safety and Health Administration said Wednesday it has put eight U.S. mines, including four in West Virginia, on notice that they have a potential pattern of violations and will face more scrutiny.The troubled mines in West Virginia are: Marfork Coal Co.'s Parker Peerless in Raleigh County; Pay Car Mining Inc.'s No. 58 Mine in McDowell County; Pine Ridge Coal Co.'s Big Mountain No. 16 in Boone County; and Rio Group Inc.'s Coalburg No. 2 Mine in Logan County.The list also includes: Nine Mile Mining's No. 3 Mine in Wise County, Va.; Manalapan Mining Co.'s RB No. 12 in Harlan County, Ky.; Big Ridge Inc.'s Willow Lake Portal in Saline County, Ill.; and Queenstake Resources' Jerritt Canyon Mill in Elko, Nev.MSHA chief Joe Main said the agency briefed operators in April about a new online tool they can use to monitor their compliance and injury records under MSHA's initial screening criteria and adjust accordingly."Unfortunately, some operators either did not use this tool or did not respond with effective improvements," he said.It's the second round of screening since MSHA established the current criteria and procedures in September 2010.The mines can now develop corrective action plans to meet targets set by MSHA. Those that fail to do so could be subject to closure orders for all significant and severe violations.MSHA says that happened for the first time in April, with Bledsoe Coal Corp.'s Abner Branch Rider Mine in Leslie County, Ky., and The New West Virginia Mining Co.'s Apache Mine in McDowell County, W.Va.