Penn Virginia Corporation filed SEC Form 8-K: Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Completion of Acquisition or Disposition of Assets, Unregistered Sales of Equity Securities, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Material Modification to Rights of Security Holders, Leadership Update, Submission of Matters to a Vote of Security Holders, Regulation FD Disclosure, Financial Statements and Exhibits