UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the Fiscal Year Ended September 30, 2019 OR ☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Commission file number 001-13601 GEOSPACE TECHNOLOGIES CORPORATION (Exact Name of Registrant as Specified in Its Charter) Texas 76-0447780 (State or Other Jurisdiction of Incorporation or Organization) (I ...