UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (date of earliest event reported): February 11, 2015

DAWSON OPERATING COMPANY

(Exact name of Registrant as specified in its charter)

Registrant’s telephone number, including area code:  (432) 684-3000

Dawson Geophysical Company

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o  Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o  Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o  Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 2.01.                                        Completion of Acquisition or Disposition of Assets.

On February 11, 2015, pursuant to the previously announced Agreement and Plan of Merger, dated October 8, 2014 (the “Merger Agreement”), by and among Dawson Operating Company, a Texas corporation previously known as Dawson Geophysical Company (the “Company”), Dawson Geophysical Company, a Texas corporation previously known as TGC Industries, Inc. (“Dawson”), and Riptide Acquisition Corp., a Texas corporation and a wholly owned subsidiary of Dawson (“Merger Sub”), Merger Sub was merged with and into the Company, with the Company continuing after the merger as the surviving entity and a wholly owned subsidiary of Dawson (the “Merger”). At the effective time of the Merger (the “Effective Time”), without any action on the part of any shareholder, each issued and outstanding share of the Company’s common stock, par value $0.331/3 per share (the “Company Common Stock”), including shares underlying the Company’s outstanding equity awards, were converted into the right to receive 1.760 shares of common stock of Dawson, par value $0.01 per share (the “Dawson Common Stock”), after giving effect to a 1-for-3 reverse stock split of Dawson Common Stock which occurred immediately prior to the Merger.  As a result of the Merger, the Company Common Stock will no longer remain listed on the NASDAQ Stock Market LLC (“NASDAQ”).

The foregoing description of the Merger Agreement and the Merger is not complete and is qualified in its entirety by reference to the Merger Agreement, which was attached as Exhibit 2.1 to the Company’s Current Report on Form 8-K filed with the Securities and Exchange Commission (the “SEC”) on October 9, 2014, and is incorporated herein by reference.

Item 3.01.                                        Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

In connection with the consummation of the Merger, the Company notified NASDAQ that each outstanding share of the Company Common Stock was converted in the Merger into the right to receive Dawson Common Stock and requested that NASDAQ (i) suspend trading of the Company Common Stock and (ii) file a Form 25 with the SEC in order to remove the Company Common Stock from listing on NASDAQ and deregister the Company Common Stock under Section 12(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The Company also intends to file a Form 15 with the SEC to suspend the Company’s duty to file reports under Sections 13(a) and 15(d) of the Exchange Act.

Item 3.03.                                        Material Modification to Rights of Security Holders.

The information required by Item 3.03 is contained in Item 2.01 and is incorporated herein by reference.

Item 5.01.                                        Changes in Control of Registrant.

The information required by Item 5.01 is contained in Item 2.01 and is incorporated herein by reference.

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Item 5.02.                                        Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

Departure of Certain Directors and Officers

Pursuant to the Merger Agreement, at the Effective Time, Craig W. Cooper, Gary M. Hoover, Ph.D., Ted R. North, Tim C. Thompson and Mark A. Vander Ploeg, who were members of the Company’s board of directors immediately prior to the Effective Time, and C. Ray Tobias, James W. Thomas and K.S. Forsdick, who were officers of the Company immediately prior to the Effective Time, ceased to be directors and officers of the Company. These actions were not a result of any disagreements with the Company on any matter relating to the Company’s operations, policies or practices.

Election of Directors and Appointment of Certain Officers

Pursuant to the Merger Agreement, Wayne A. Whitener and C. Ray Tobias have been elected to the Company’s board of directors. Also pursuant to the Merger Agreement, James K. Brata was appointed as the Company’s Chief Financial Officer, replacing Christina W. Hagan, who continues in her role as the Company’s Secretary and who was also appointed Chief Accounting Officer of the Company.

James K. Brata, 59, is Dawson’s Executive Vice President and Chief Financial Officer in addition to his role as Chief Financial Officer of the Company. He served as Secretary and Treasurer of Dawson from March 2009 to February 2015; Chief Financial Officer of Dawson since October 2008; Vice President of Dawson since June 2008. Prior to joining Dawson, Mr. Brata served in a variety of capacities at publicly traded companies including Sport Supply Group, Research Institute of America, a wholly owned subsidiary of Thomson Reuters Corporation, Compaq Computer Corporation, now part of Hewlett Packard Company, and Mitchell Energy and Development Corporation which was acquired by Devon Energy Corporation. Mr. Brata was also a consultant with KPMG LLP and Coopers & Lybrand, now PricewaterhouseCoopers LLP. Mr. Brata holds a B.S. degree in Accounting, a M.B.A. in finance, and is a Certified Public Accountant.

Item 5.03.                                        Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On February 11, 2015, pursuant to the Merger Agreement, the certificate of formation of the Company was amended and restated (i) to reflect the change of the name of the Company to “Dawson Operating Company” and (ii) to make other technical amendments to conform with the requirements of the Texas Business Organizations Code.  A copy of the Company’s amended and restated certificate of formation is attached hereto as Exhibit 3.1 and is incorporated herein by reference.

In addition, on February 11, 2015, pursuant to the Merger Agreement, the bylaws of the Company were amended (1) to reflect the change of the name of the Company to “Dawson Operating Company” and (2) to change the Company’s fiscal year end from September 30 to December 31. A copy of Amendment No. 4 to Second Amended and Restated Bylaws of the Company is attached hereto as Exhibit 3.2 and is incorporated herein by reference.

Item 8.01.                                        Other Events.

On February 11, 2015, the Company and Dawson issued a joint press release announcing the consummation of the Merger. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

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Item 9.01.                                        Financial Statements and Exhibits.

(d) Exhibits.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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INDEX TO EXHIBITS

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Exhibit 3.1

RESTATED

CERTIFICATE OF FORMATION

OF

DAWSON GEOPHYSICAL COMPANY

February 9, 2015

Dawson Geophysical Company (the “Corporation”), pursuant to the provisions of Section 21.056 of the Texas Business Organizations Code (the “Code”), hereby adopts this Restated Certificate of Formation (this “Restated Certificate of Formation”), which completely supersedes and replaces the Corporation’s Second Restated Articles of Incorporation filed with the Texas Secretary of State on May 15, 2006, as restated (the “Certificate of Formation”).

1.              The name of the Corporation as currently shown in the records of the Texas Secretary of State is “DAWSON GEOPHYSICAL COMPANY.”  The file number issued to the Corporation by the Secretary of State is 12902300.  The date of formation of the Corporation is November 4, 1955.

2.              The Corporation is a Texas for-profit corporation.

3.              This Restated Certificate of Formation makes new amendments to the Certificate of Formation.  The following is an identification by reference or description of the provisions of the Certificate of Formation which have been amended: (i) Article One is amended to change the Corporation’s name to “DAWSON OPERATING COMPANY,” (ii) various articles are amended to conform terms and references specified by the Texas Business Organizations Code, (iii) Article Two, which previously identified the duration of the Corporation, now identifies the entity type, (iv) paragraph (c) of Article Four has been changed to reflect that the stock split described therein occurred in the past and (v) Article Six is updated with respect to the identification of the current members of the Board of Directors.

4.              Each new amendment has been made in accordance with the provisions of the Code. The amendments to the Certificate of Formation and the Restated Certificate of Formation have been approved in the manner required by the Code and the governing documents of the Corporation.

5.              The Restated Certificate of Formation, which is attached to this form, accurately states the text of the Certificate of Formation being restated and each amendment to the Certificate of Formation that is in effect, as further amended by this Restated Certificate of Formation. The attached Restated Certificate of Formation does not contain any other change in the Certificate of Formation being restated except for the information permitted to be omitted under Section 3.059(b) of the Code and as set forth in paragraph 3 above.

6.              The text of the Certificate of Formation being restated and amended by this Restated Certificate of Formation are hereby completely superseded and replaced with the following:

ARTICLE ONE

The name of the corporation is DAWSON OPERATING COMPANY.

ARTICLE TWO

The corporation is organized as a for-profit corporation under the Texas Business Organizations Code.

ARTICLE THREE

The purposes for which this corporation is organized are:

To engage in any lawful activity or business and to promote and conduct any legitimate object of purpose or purposes permitted under the laws of the State of Texas, and to enable the corporation to accomplish such purposes, the corporation shall have and possess and exercise all of the rights, powers and privileges granted to or conferred upon corporations by the Texas Business Organizations Code

or by any other law of the State of Texas or by this Restated Certificate of Formation, together with all other rights, powers and privileges incident thereto that shall or may be necessary or convenient to the conduct of such activities and business and the achievement of such purposes.

ARTICLE FOUR

The total number of shares of stock which the corporation shall have authority to issue is fifty-five million (55,000,000) divided into two classes:

(a) One class designated as common stock shall consist of Fifty Million (50,000,000) shares having a par value of Thirty-Three and One/third Cents ($0.33-1/3) per share; and the other class designated as preferred shares shall consist of Five Million (5,000,000) shares having a par value of One Dollar ($1.00) per share.

(b) The preferences, qualifications, limitations, restrictions in the special or relative right in respect to the shares are as follows:

(1) Shares of Preferred Stock may be issued from time to time in one or more series to have distinctive serial designations, as shall hereafter be determined in the resolution or resolutions providing for the issue of such Preferred Stock from time to time adopted by the Board of Directors pursuant to authority as so to do which is hereby vested in the Board of Directors.

(2) Each series of Preferred Stock:

(a) may have such number of shares;

(b) may not have voting powers without the prior approval of the holders of a majority of the Common Stock except when dividends are in arrears for twelve (12) months;

(c) may be subject to redemption at such time or times and at such prices;

(d) may be entitled to receive dividends (which may be cumulative or noncumulative) at such rate or rates, on such conditions, from such date or dates, and at such times, and payable in preference to, or in relation to, the dividends payable on any other class or classes or series of stock;

(e) may have such rights upon the dissolution of, or upon any distribution of the assets of, the corporation;

(f) may be made convertible at not less than book value into, or exchangeable for, shares of any other class or classes (except a class having prior or superior rights and preferences as to dividends or distribution of assets upon liquidation) or of any other series of the same or any other class or classes of stock of the corporation at such price or prices or at such rates of exchange, and with such adjustments without the approval of the holders of a majority of the Common Stock;

(g) may be entitled to the benefit of a sinking fund or purchase fund to be applied to the purchase or redemption of shares of such series in such amount or amounts;

(h) may be entitled to the benefit of conditions and restrictions upon the creation of indebtedness of the corporation or any subsidiary, upon the issue of any additional stock (including additional shares of such series or of any other series) and upon the payment of dividends or the making of other distributions on, and the purchase, redemption or other acquisition by the corporation or any subsidiary of any outstanding stock of the corporation; and

(i) may have such other relative, participating optional or other special rights, and qualifications, limitations or restrictions thereof; all as shall be stated in said resolution or resolutions providing for the issue of such Preferred Stock. Except where otherwise set forth in the resolution or resolutions adopted by the Board of Directors providing for the issue of any series of Preferred Stock, the number of shares comprising such series may be increased or decreased (but not below the number of shares then outstanding) from time to time by like action of the Board of Directors.

(3) Shares of any series of Preferred Stock which have been redeemed (whether through the operation of a sinking fund or otherwise) or purchased by the corporation, or which, if convertible or exchangeable, have been converted into or exchanged for shares of stock of any other class or classes shall have the status of authorized and unissued shares of Preferred Stock and may be reissued as a part of the series of which they were originally a part or may be reclassified and reissued as part of a new series of Preferred Stock to be created by resolution or resolutions adopted by the Board of Directors providing for the issue of any series of Preferred Stock and to any filing required by law.

(4) Except as otherwise provided by law or by the resolution or resolutions of the Board of Directors providing for the issue of any series of the Preferred Stock, the Common Stock shall have the exclusive right to vote for the election of Directors and for all other purposes, each holder of the Common Stock being entitled to one vote for each share held.

Subject to all of the rights of the Preferred Stock or any series thereof, the holders of the Common Stock shall be entitled to receive, when, as and if declared by the Board of Directors, out of funds legally available therefor, dividends payable in cash, stock or otherwise.

Upon any liquidation, dissolution or winding up of the corporation, whether voluntary or involuntary, and after the holders of the Preferred Stock of each series shall have been paid in full the amounts to which they respectively shall be entitled or a sum sufficient for such payment in full shall have been set aside, the remaining net assets of the corporation shall be distributed pro rata to the holders of the Common Stock in accordance with their respective rights and interests, to the exclusion of the holders of the Preferred Stock.

(c) Effective as of May 15, 2006 (referred to as the “Effective Date”), each of the 80,580 shares of common stock of the corporation outstanding prior to the Effective Date, having a par value of Ten Dollars ($10.00) per share, were made equal to and changed into thirty (30) fully paid and nonassessable shares of common stock of the corporation having a par value of Thirty-Three and One/third Cents ($0.33-1/3) per share (the “Stock Split”), and were authorized to be issued under the Certificate of Formation, as previously amended. Certificates for shares of common stock having a par value of Thirty-Three and One/third Cents ($0.33-1/3) per share were issued in place and upon surrender of certificates of shares of the previously issued common stock having a par value of $10.00 per share. As of the Effective Date and thereafter, a certificate representing shares of common stock prior to the Stock Split were deemed to represent the number of new shares into which the old shares were convertible.

No stockholder of this corporation shall by reason of his holding shares of any class have any pre-emptive or preferential right to purchase or subscribe to any shares of any class of this corporation, now or hereafter to be authorized, or any notes, debentures, bond or other securities convertible into or carrying options or warrants to purchase shares of any class, now or hereafter to be authorized, whether or not the issuance of any such shares, or such notes, debentures, bonds or other securities, would adversely affect the dividend or voting rights of such stockholder, other than such rights, if any, as the Board of Directors, in its discretion from time to time may grant, and at such price as the Board of Directors in its discretion may fix; and the Board of Directors may issue shares of any class of this corporation, or any notes, debentures, bonds or other securities convertible into or carrying options or warrants to purchase shares of any class, without offering any such shares of any class, either in whole or in part, to the existing stockholders of any class.

A cumulative voting by the stockholders of the corporation at any election for directors is expressly prohibited. The shareholders entitled to vote for directors in such election shall be entitled to cast one vote per directorship for each share held, and no more.

ARTICLE FIVE

The corporation will not commence business until it has received for issuance of its shares consideration of the value of One Thousand Dollars ($1,000.00), consisting of money, labor done, or property actually received, which sum is not less than One Thousand ($1,000.00).

ARTICLE SIX

The post office address of its registered agent is 508 W. Wall, Suite 800, Midland, Texas, and the name of its registered agent at such address is Stephen C. Jumper. The Board of Directors consists of six directors.  The post office address of each director is 508 W. Wall, Suite 800, Midland, Texas, and the name of the persons serving as directors of the corporation at the time of the filing of this

Restated Certificate of Formation and who shall serve until their successors shall be chosen and shall qualify are: Stephen C. Jumper, Craig W. Cooper, Gary M. Hoover, Ph.D., Mark Vander Ploeg, Ted R. North, and Tim C. Thompson.

ARTICLE SEVEN

A director of the corporation shall not be personally liable to the corporation or its shareholders for monetary damages for an act or omission in such director’s capacity as a director, except for liability for (i) a breach of a director’s duty of loyalty to the corporation or its shareholders; (ii) an act or omission not in good faith or that involves intentional misconduct or a knowing violation of the law; (iii) a transaction from which a director received an improper benefit, whether or not the benefit resulted from an action taken within the scope of the director’s office; (iv) an act or omission for which the liability of a director is expressly provided by statute; or (v) an act related to an unlawful stock repurchase or payment of a dividend. If the laws of the State of Texas are hereafter amended to authorize corporate action further eliminating or limiting the personal liability of a director of the corporation, then the liability of a director of the corporation shall thereupon automatically be eliminated or limited to the fullest extent permitted by such laws. Any repeal or modification of this Article Seven by the shareholders of the corporation shall not adversely affect any right or protection of a director existing at the time of such repeal or modification with respect to events or circumstances occurring or existing prior to such time.

[Signature Page to Follow]

This Restated Certificate of Formation becomes effective at 4:01 p.m., Central Time, on February 11, 2015.

Exhibit 3.2

Amendment No. 4

TO THE

SECOND AMENDED AND RESTATED BYLAWS

OF DAWSON OPERATING COMPANY

The Second Amended and Restated Bylaws, as amended (the “Bylaws”) of Dawson Operating Company, previously known as Dawson Geophysical Company, a Texas corporation (the “Corporation”), are hereby amended as of February 11, 2015, as follows:

1.              The name of the Corporation, as set forth in the title of the bylaws, is amended in its entirety to be replaced with the following:

“DAWSON OPERATING COMPANY”

2.              Article VII, Section 4 of the Bylaws is hereby amended in its entirety and replaced with the following:

Section 4. Fiscal Year. The fiscal year of the Corporation shall begin on the first day of January of each year and end on the last day of December of each year.

Exhibit 99.1

NEWS RELEASE

DAWSON GEOPHYSICAL ANNOUNCES COMPLETION OF

STRATEGIC BUSINESS COMBINATION

Combined Company renamed “Dawson Geophysical Company”

and to continue trading on NASDAQ under “DWSN”

MIDLAND, Texas, February 11, 2015 — Dawson Geophysical Company, previously known as TGC Industries, Inc., today announced the completion of its previously announced strategic business combination effective February 11, 2015. Trading in the combined company’s common stock will open on NASDAQ on February 12, 2015 under the symbol “DWSN” on a post-split basis (CUSIP No. 239360100).

Under the terms of the transaction, which was structured as a stock-for-stock merger and intended to qualify as a tax-free reorganization, Dawson Operating Company, previously known as Dawson Geophysical Company (“Legacy Dawson”), merged with a wholly owned subsidiary of Dawson Geophysical Company (the “Combined Company”), previously known as TGC Industries, Inc. (“Legacy TGC”) and continued as the surviving entity and a wholly owned subsidiary of the Combined Company. As consideration for the transaction, all outstanding shares of Legacy Dawson’s common stock, par value $0.331/3 per share, were converted into the right to receive 1.760 shares of Legacy TGC’s common stock, par value $0.01 per share, after giving effect to a 1-for-3 reverse stock split of Legacy TGC’s common stock. Immediately prior to the effective time of the transaction, Legacy Dawson changed its name to “Dawson Operating Company” and Legacy TGC changed its name to “Dawson Geophysical Company”.

After the close of regular NASDAQ trading hours on February 11, 2015, and immediately prior to the effective time of the transaction, Legacy TGC effected a 1-for-3 reverse stock split of its outstanding common stock. As a result of the reverse stock split, every three (3) shares of Legacy TGC’s common stock outstanding immediately prior to the transaction were combined and reclassified into one (1) share of Legacy TGC common stock. No fractional shares will be issued in connection with the reverse stock split. Instead, each fractional share to be issued to a Legacy TGC shareholder will be rounded up to the nearest whole share.

Legacy TGC retained its transfer agent, American Stock Transfer & Trust Company, LLC (“AST”), to act as its exchange agent for the reverse stock split.  AST will provide shareholders of record of Legacy TGC immediately prior to the merger, which was the effective time of the reverse stock split, with a letter of transmittal providing instructions for the exchange of their certificates and book-entry shares representing pre-reverse stock split shares for certificates and book-entry shares representing post-reverse stock split shares in the name of the Combined Company. Shareholders owning shares through a broker or other nominee will have their

positions automatically adjusted to reflect the reverse stock split, subject to brokers’ particular processes, and will not be required to take any action in connection with the reverse stock split and the name change of the Combined Company.

The consummation of the reverse stock split reduced the number of Legacy TGC’s outstanding shares of common stock on a pre-transaction basis from approximately 22.0 million shares to 7.3 million shares. Immediately after the issuance of shares to Legacy Dawson’s shareholders in connection with the transaction, the Combined Company had approximately 21.6 million shares of common stock outstanding, with Legacy Dawson shareholders owning approximately 66% of the Combined Company and Legacy TGC shareholders owning approximately 34% of the Combined Company. The Combined Company is authorized to issue an aggregate of 35.0 million shares of common stock, including the shares mentioned above.  AST is also acting as the exchange agent in connection with the transaction and will send to the former registered holders of Legacy Dawson’s common stock a letter of transmittal containing instructions on how to exchange Legacy Dawson stock certificates and book-entry shares for certificates and book-entry shares of the Combined Company.

The Combined Company is operating under the leadership of Stephen Jumper, who serves as the Combined Company’s Chairman, President and Chief Executive Officer, and Wayne Whitener, who serves as an officer of the Combined Company and as Vice Chairman of the Combined Company’s board of directors. In addition to Messrs. Jumper and Whitener, the Combined Company’s board of directors includes four members of the Legacy Dawson board—Craig Cooper, Gary Hoover, Ted North and Mark Vander Ploeg—and two members of the Legacy TGC board —William Barrett and Dr. Allen McInnes. In addition to Messrs. Jumper and Whitener, the board of directors of the Combined Company appointed James K. Brata, Christina W. Hagan, James W. Thomas, C. Ray Tobias and Daniel G. Winn as officers of the Combined Company.

Raymond James & Associates, Inc. served as financial advisor to Legacy Dawson while Stephens Inc. served as financial advisor to Legacy TGC. Baker Botts L.L.P. served as legal counsel to Legacy Dawson while Haynes and Boone, LLP served as legal counsel to Legacy TGC.

About Dawson Geophysical

Dawson Geophysical Company is a leading provider of U.S. onshore seismic data acquisition services with operations throughout the continental United States and Canada.  Dawson acquires and processes 2-D, 3-D and multi-component seismic data solely for its clients, ranging from major oil and gas companies to independent oil and gas operators as well as providers of multi-client data libraries.

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Safe Harbor Provisions

In accordance with the Safe Harbor provisions of the Private Securities Litigation Reform Act of 1995, the Combined Company cautions that statements in this press release which are forward-looking and which provide other than historical information involve risks and uncertainties that may materially affect the Combined Company’s actual results of operations. Such forward looking statements are based on the beliefs of management as well as assumptions made by and information currently available to management. Actual results could differ materially from those contemplated by the forward looking statements as a result of certain factors. These risks include but are not limited to the risk that the benefits from the transaction may not be fully realized or may take longer to realize than expected; the ability to promptly and effectively integrate the businesses of Legacy Dawson and Legacy TGC; the ability to realize anticipated synergies and cost savings from the transaction; the reaction of the companies’ customers, employees and counterparties to the transaction; diversion of management time on transaction-related issues; the volatility of oil and natural gas prices; dependence upon energy industry spending; industry competition; reduced utilization; delays, reductions or cancellations of service contracts; high fixed costs of operations and high capital requirements; external factors affecting the Combined Company’s crews such as weather interruptions and inability to obtain land access rights of way; disruptions in the global economy; whether the Combined Company enters into turnkey or dayrate contracts; crew productivity; the limited number of clients; credit risk related to clients; and the availability of capital resources. A discussion of these and other factors, including risks and uncertainties with respect to the Combined Company is set forth in Legacy Dawson’s Annual Report on Form 10-K for the fiscal year ended September 30, 2014 and in the Registration Statement on Form S-4 filed by Legacy TGC on November 6, 2014, as amended. The Combined Company disclaims any intention or obligation to revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

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