UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 1)*

                              TGC INDUSTRIES, INC.
                                (Name of Issuer)

                   8-1/2% SENIOR CONVERTIBLE PREFERRED STOCK
                                       AND
                  COMMON STOCK (NEW), $.30 PAR VALUE PER SHARE

                         (Title of Class of Securities)

                                    872417308
                                 (CUSIP Number)

  RICHARD E. BLOHM, JR. 1415 LOUISIANA STREET, SUITE 3000, HOUSTON, TEXAS 77002
                                 (713) 739-6500
 (Name, Address and Telephone Number of Person Authorized to Receive Notices and
                                 Communications)

                                 with a copy to:

     DARRYL M. BURMAN, 1900 W. LOOP SOUTH, SUITE 1100, HOUSTON, TEXAS 77027

                               FEBRUARY 17, 2004
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(b)(3) or (4), check the following box [ ].

NOTE: Six copies of this statement, including all exhibits, should be filed with
the Commission. See Rule 13d-1(a) for other parties to whom copies are to be
sent.

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.



CUSIP NO. 872417308                   13D                            PAGE 2 OF 7

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1.       NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE
         PERSON: WEDGE Energy Services, L.L.C.; Tax I.D. No. 76-0624532

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2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:    (a) [ ]   (b)  [ ]

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3.       SEC USE ONLY:

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4.       SOURCE OF FUNDS

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5.       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT   [ ]
         TO ITEMS 2(d) OR 2(e)

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6.       CITIZENSHIP OR PLACE OF ORGANIZATION:
         United States

- --------------------------------------------------------------------------------
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

          7.     SOLE VOTING POWER:            -0-
          8.     SHARED VOTING POWER:          3,041,568
          9.     SOLE DISPOSITIVE POWER:       -0-
         10.     SHARED DISPOSITIVE POWER:     3,041,568

- --------------------------------------------------------------------------------
11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
         3,024,264 shares of 8.5% Senior Convertible Preferred Stock
         (convertible 1:1)
         17,304 shares of Common Stock for a total of
         3,041,568 Common Shares if fully converted

- --------------------------------------------------------------------------------
12.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
         SHARES                                                              [ ]

- --------------------------------------------------------------------------------
13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):
         31.3% of Common Stock on a fully converted, fully diluted basis

- --------------------------------------------------------------------------------
14.      TYPE OF REPORTING PERSON:
         OO: Limited Liability Company

- --------------------------------------------------------------------------------



CUSIP NO. 872417308                   13D                            PAGE 3 OF 7

- --------------------------------------------------------------------------------
1.       NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE
         PERSON:
         Issam M. Fares

- --------------------------------------------------------------------------------
2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:    (a) [ ]    (b) [ ]

- --------------------------------------------------------------------------------
3.       SEC USE ONLY:

- --------------------------------------------------------------------------------
4.       SOURCE OF FUNDS

- --------------------------------------------------------------------------------
5.       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e)                                                  [ ]

- --------------------------------------------------------------------------------
6.       CITIZENSHIP OR PLACE OF ORGANIZATION:
         Lebanon

- --------------------------------------------------------------------------------
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

          7.     SOLE VOTING POWER:         -0-
          8.     SHARED VOTING POWER:       3,041,568
          9.     SOLE DISPOSITIVE POWER:    -0-
         10.     SHARED DISPOSITIVE POWER:  3,041,568

- --------------------------------------------------------------------------------
11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
         3,024,264 shares of 8.5% Senior Convertible Preferred Stock
         (convertible 1:1)
         17,304 shares of Common Stock for a total of
         3,041,568 Common Shares if fully converted

- -------------------------------------------------------------------------------
12.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
                                                                             [ ]
- --------------------------------------------------------------------------------
13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):
         31.3% of Common Stock on a fully converted, fully diluted basis

- --------------------------------------------------------------------------------
14.      TYPE OF REPORTING PERSON:
         IN

- --------------------------------------------------------------------------------



CUSIP NO. 872417308                   13D                            PAGE 4 OF 7

ITEM 1. SECURITY AND ISSUER.

         8-1/2% Convertible Subordinated Debenture, Series B, due December 1,
2009, as subsequently converted into 8.5% Senior convertible Preferred Stock
("Preferred Stock"), which are convertible at the election of Wedge Energy
Services, LLC into shares of Common Stock of TGC Industries, Inc., the president
of which is Wayne Whitener, and his principal place of business is located at
1304 Summit Avenue, Suite 2, Plano, Texas 75074. All information herein with
respect to TGC Industries, Inc., a Texas corporation, is to the best knowledge
and belief of the Reporting Persons, as defined herein.

ITEM 2. IDENTITY AND BACKGROUND.

         This Schedule 13D is filed by:

         WEDGE Energy Services, L.L.C., a Texas limited liability company
("WEDGE"), and Mr. Issam M. Fares, an individual ("Fares" and, together with
WEDGE, the "Reporting Persons").

         The address of the principal place of business for WEDGE is 1415
Louisiana Street, Suite 3000, Houston, Texas 77002; and the address of Mr. Fares
is Pietermaai 15, Curacao, Netherlands Antilles. Mr. Fares is a citizen of the
country of Lebanon.

         Mr. James M. Tidwell, is Vice President of WEDGE and also serves on the
Board of Directors. Mr. Blohm is the Secretary of WEDGE and also serves on the
Board of Directors. The filing of this Statement on Schedule 13D shall not be
construed as an admission that Mr. Tidwell or Mr. Blohm is, for the purposes of
Section 13(b) or Section 13(g) of the Securities Exchange Act of 1934, as
amended (the "Act"), the beneficial owner of any securities covered by this
Statement.

         Neither WEDGE nor Mr. Fares, to the knowledge of Mr. Tidwell or Mr.
Blohm, has been during the last five years (i) convicted of any criminal
proceeding (excluding traffic violations or similar misdemeanors) or (ii) a
party to a civil proceeding of a judicial or administrative body of competent
jurisdiction, and as a result of such proceeding, was or is subject to a
judgment, decree or final order enjoining future violation of, or prohibiting or
mandating activities subject to, United States federal or state securities laws
or finding any violation with respect to such laws. Since Mr. Fares resides
outside of the United States, he has requested WEDGE Group Incorporated, a
corporation organized under the laws of the state of Delaware ("WGI"), to advise
the Reporting Persons with respect to acquisition, holding, voting and
disposition strategies regarding the Common Stock of the Issuer. Mr. Fares is
the ultimate beneficial owner of all of the outstanding ownership interests of
each of WEDGE and WGI. The address of the principal business office of WGI is
1415 Louisiana Street, Suite 3000, Houston, Texas 77002. Additionally, WEDGE is
an affiliate of WGI. The filing of this Statement on Schedule 13D shall not be
construed



CUSIP NO. 872417308                   13D                            PAGE 5 OF 7

as an admission that WGI is, for the purposes of Section 13(d) or Section 13(g)
of the Act, the beneficial owner of any securities covered by this Statement.

ITEM 3. SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

         The Reporting Persons have entered into several Preferred Stock
Purchase Agreements and several Escrow Agreements for the aggregated sale of
100% of their 8.5% Senior Convertible Preferred Stock to certain unrelated
individuals (as reflected on Exhibit 7(d) attached hereto) for a combined,
aggregate consideration of $1,602,859.92 to be paid by said individuals from
sources unknown to the Reporting Persons. The forms of the Preferred Stock
Purchase Agreements and the Escrow Agreements containing all terms of the
transaction described herein are attached hereto as Exhibits 7(a) and 7(b).

         Concurrent with the transaction reflected above, the Reporting Persons
have entered into a Financial Services Agreement with Barrett Gardner
Associates, Inc. In addition to a cash payment, the consideration to be paid by
the Reporting Persons for the services received includes 17,304 shares of the
Common Stock of the Issuer which represents 100% of the Reporting Persons
holdings in Common Stock of the Issuer. The Common Stock will be transferred
through the same escrow account arrangement as the preferred securities
transaction described in the preceding paragraph. A copy of the Financial
Services Agreement is attached hereto as Exhibit 7(c).

ITEM 4. PURPOSE OF TRANSACTION.

         The Reporting Persons have entered into several Preferred Stock
Purchase Agreements and several Escrow Agreements for the aggregated sale of
100% of their 8.5% Senior Convertible Preferred Stock to certain unrelated
individuals (as reflected on Exhibit 7(d) attached hereto) for a combined,
aggregate consideration of $1,602,859.92 to be paid by said individuals from
sources unknown to the Reporting Persons. The forms of the Preferred Stock
Purchase Agreements and the Escrow Agreements containing all terms of the
transaction described herein are attached hereto as Exhibits 7(a) and 7(b).

         Concurrent with the transaction reflected above, the Reporting Persons
have entered into a Financial Services Agreement with Barrett Gardner
Associates, Inc. In addition to a cash payment, the consideration to be paid by
the Reporting Persons for the services received includes 17,304 shares of the
Common Stock of the Issuer which represents 100% of the Reporting Persons
holdings in Common Stock of the Issuer. The Common Stock will be transferred
through the same escrow account arrangement as the preferred securities
transaction described in the preceding paragraph. A copy of the Financial
Services Agreement is attached hereto as Exhibit 7(c).

         The Reporting Persons intend to sell their entire investment of Common
Stock and Preferred Stock in the Issuer.



CUSIP NO. 872417308                   13D                            PAGE 6 OF 7

         The Preferred Stock is being sold at $0.53 per share and carries
certain rights and preferences as described in the 8.5% Convertible Subordinated
Debenture Agreement, Series B. However, by agreement with the Issuer, the
purchasers in this transaction may not acquire all of the rights and preferences
held by the Reporting Persons.

         Following the transaction, certain of the purchasers may own or
control, in combination with their existing ownership of Securities of the
Issuer, greater than five percent (5%) of the outstanding Common Stock of the
Issuer on a fully converted, fully diluted basis.

         While the Reporting Persons have no present intent to make future
investments in the Issuer, nothing herein shall be construed to limit or
restrict the Reporting Persons in the event such intent would change in the
future.

ITEM 5. INTEREST IN SECURITIES OF THE ISSUER.

         In the aggregate, following the sale of the Preferred Stock and the
transfer of the Common Stock, the Reporting Persons will have no ownership of
any type in the Issuer.

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO
        SECURITIES OF THE ISSUER.

         The form of the Preferred Stock Purchase Agreement and Financial
Services Agreement are attached as Exhibits 7(a) and 7(c). Following the closing
of the transaction reported herein, the Reporting Persons shall have no further
ownership interests in the Issuer and no contractual rights or obligations with
the Issuer.

ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.

         (a)      Form of the Preferred Stock Purchase Agreement

         (b)      Form of the Escrow Agreement

         (c)      Financial Services Agreement

         (d)      Schedule of Purchasers

         (e)      Power of Attorney from Issam M. Fares

         (f)      Joint Filing Agreement



CUSIP NO. 872417308                   13D                            PAGE 7 OF 7

SIGNATURES

         After reasonable inquiry and to the best of signatories' knowledge and
belief, the undersigned certify that the information set forth in this statement
is true, complete and correct.

                                      WEDGE ENERGY SERVICES, L.L.C.

February 17, 2004                     /s/ James M. Tidwell
- -----------------------               ------------------------------------------
         Date                         Name: James M. Tidwell
                                      Title: Vice President

                                      ISSAM M. FARES

February 17, 2004                     By: /s/ Richard E. Blohm, Jr.
- -----------------------                  ---------------------------------------
         Date                             Richard E. Blohm, Jr.
                                          Attorney-In-Fact



                                 EXHIBIT INDEX

         (a)      Form of the Preferred Stock Purchase Agreement

         (b)      Form of the Escrow Agreement

         (c)      Financial Services Agreement

         (d)      Schedule of Purchasers

         (e)      Power of Attorney from Issam M. Fares

         (f)      Joint Filing Agreement



                                                                     EXHIBIT (a)

                              TGC INDUSTRIES, INC.

                       PREFERRED STOCK PURCHASE AGREEMENT

         THIS PREFERRED STOCK PURCHASE AGREEMENT (the "Agreement") is made and
entered into effective as of the 12th day of February, 2004, by and among WEDGE
ENERGY SERVICES, L.L.C., a Delaware limited liability company (the "Seller" or
"WEDGE"), and the undersigned purchaser set forth on the signature page hereof
(the "Purchaser") with respect to the sale by WEDGE to the Purchaser of the
number of shares of 8-1/2% SENIOR CONVERTIBLE PREFERRED STOCK (the "Senior
Preferred Stock") of TGC Industries, Inc., a Texas corporation (the "Company")
as set forth adjacent to the Purchaser's signature on the signature page hereof.

         WHEREAS, Seller desires to sell to Purchaser and Purchaser desires to
purchase from Seller the shares of Senior Preferred Stock under terms and
conditions set forth herein; and

         WHEREAS, Seller and Purchaser understand that the transaction pursuant
to this Agreement is a part of the sale by WEDGE of all of its 3,024,264 shares
of Senior Preferred Stock of the Company for a total cash consideration of
$1,602,859.92 and that the Closing of the transaction pursuant to this Agreement
will be conditioned on and simultaneous with the closing of the transactions for
the sale by WEDGE to the other purchasers pursuant to Preferred Stock Purchase
Agreements of like tenor to this Agreement.

         WHEREAS, WEDGE has entered into a Financial Advisory Services Agreement
with Barrett Gardner Associates, Inc. ("Barrett Gardner") for Barrett Gardner to
provide certain financial advisory services to assist WEDGE in connection with
the sale of the Senior Preferred Stock for an advisory fee of $102,860.00 plus
17,304 shares of Common Stock of the Company, to be paid to Barrett Gardner by
WEDGE at the Closing.

         NOW THEREFORE, in consideration of the foregoing and the covenants of
the parties contained herein, it is hereby agreed as follows:

         1.       Purchase and Sale of Senior Preferred Stock; Purchase Price.
Subject to the terms and conditions set forth herein, at the Closing, as defined
below, Seller will sell and Purchaser will purchase the number of shares of
Senior Preferred Stock set forth adjacent to the Purchaser's signature on the
signature page hereof at the purchase price set forth on the signature page
hereof, which represents a purchase price of fifty three cents ($0.53) per share
of Senior Preferred Stock (the "Purchase Price").

                                                                          Page 1



         2.       Closing; Closing Deliveries. The closing of the purchase and
sale of the Senior Preferred Stock (the "Closing") should take place at the
offices of Law, Snakard & Gambill, P.C., 1600 West Seventh Street, Suite 500,
Fort Worth, Texas 76102, upon the execution and delivery of this Agreement by
Seller and Purchaser and upon the execution and delivery of agreements of like
tenor between WEDGE and the other purchasers for the sale and purchase, in the
aggregate, of all of Seller's 3,024,264 shares of Senior Preferred Stock. At the
Closing, the Seller shall deliver certificate(s) representing its shares of
Senior Preferred Stock duly endorsed for transfer, against delivery by the
Purchaser of the Purchase Price by Purchaser's check or by wire transfer. It is
understood and agreed by Seller and Purchaser that the above deliveries of
certificates representing the shares of Senior Preferred Stock and of the
Purchase Price by check or wire transfer will be delivered pursuant to an Escrow
Agreement entered into contemporaneously herewith between Seller, Purchaser,
Barrett Gardner and Law, Snakard & Gambill, P.C., as escrow agent. (This
Agreement and the Escrow Agreement may be referred to collectively as the
"Transaction Documents").

         3.       Representations and Warranties of Seller. Seller hereby
represents and warrants to Purchaser that:

                  3.1      Power and Authority. Seller has all requisite power
         and authority, without restriction, to sell, transfer and deliver the
         shares of Senior Preferred Stock to Purchaser. All company actions on
         the part of Seller and it's officers and owners necessary for the
         authorization, execution and delivery of the Transaction Documents, the
         performance of all of its obligations thereunder, and the delivery of
         the shares of Senior Preferred Stock have been taken, and each of the
         Transaction Documents has been duly and validly executed and delivered
         by Seller and constitutes a valid and legally binding obligation of
         Seller, enforceable in accordance with its terms, except only as may be
         limited by the availability of equitable remedies and by applicable
         bankruptcy, insolvency, reorganization, moratorium or other laws
         affecting creditor's rights generally.

                  3.2      Title. Seller is the record and beneficial owner of
         the shares of Senior Preferred Stock and has good title to the Senior
         Preferred Stock, and upon the sale, transfer and delivery to Purchaser
         of the Senior Preferred Stock at the Closing, Purchaser will obtain
         good title to such Senior Preferred Stock, free and clear of all liens,
         encumbrances, security interests, exceptions or claims of any nature
         whatsoever; and

                  3.3      No Conflicts. The execution and delivery by Seller of
         the Transaction Documents, and the consummation of the transactions
         contemplated thereby:

                                                                          Page 2



                           (a)      do not violate or conflict with or
                           constitute a default under, or result in the creation
                           of any security interest in or lien upon, the shares
                           of Senior Preferred Stock, any agreement, security
                           agreement, mortgage, or other instrument to which
                           Seller is a party or by which it or the Preferred
                           Stock is bound; or

                           (b)      do not violate any statute, law, rule, or
                           regulation or the order, writ, injunction, or decree
                           of any court or governmental authority; or

                           (c)      do not require the approval, authorization,
                           or consent of any third party.

         4.       Representations and Warranties of Purchaser. The Purchaser
hereby represents and warrants to the Seller, as to and on behalf of itself only
that:

                  4.1      Power and Authority. Purchaser has all requisite
         power and authority, without restriction, to perform its obligations
         under the Transaction Documents. All action on the part of Purchaser,
         necessary for the authorization, execution and delivery of the
         Transaction Documents, the performance by Purchaser of its obligations
         thereunder, and the delivery of the Purchase Price has been taken, and
         each of the Transaction Documents has been duly and validly executed
         and delivered by Purchaser and constitutes a valid and legally binding
         obligation of Purchaser, enforceable in accordance with its terms,
         except only as may be limited by the availability of equitable remedies
         and by applicable bankruptcy, insolvency, reorganization, moratorium or
         other laws affecting creditor's rights generally.

                  4.2      Purchase Entirely for Own Account. The Senior
         Preferred Stock is being acquired or will be acquired for the
         Purchaser's own account, not as a nominee or agent, and not with a view
         toward the resale or distribution of any part thereof. The Purchaser
         does not have any contract, undertaking, agreement or arrangement with
         any person to sell, transfer or grant participations to such person or
         to any third person, with respect to any of the Senior Preferred Stock.
         Purchaser expressly represents that he, she or it is not acting in the
         capacity as an "underwriter" as that term is defined in the Securities
         Act of 1933 (the "Securities Act"). The Purchaser understands that
         ownership of securities convertible into a class of registered
         securities under the Securities Act may be subject to certain federal
         reporting requirements as a result of such Purchaser being deemed a
         beneficial owner of a certain minimum amount of the Senior Preferred
         Stock and that such Purchaser may be subject to certain timely
         reporting requirements. Purchaser has obtained Purchaser's own
         independent legal counsel to assist in analyzing its reporting
         obligations under the Securities and Exchange Act of 1934

                                                                          Page 3



         and Purchaser is not relying on any advice or input from Seller or its
         counsel for any securities matters.

                  4.3      Investment Experience. Purchaser is experienced in
         evaluating and investing in securities and acknowledges that he, she or
         it is able to fend for himself, herself or itself, can bear the
         economic risk of the investment, and has such knowledge and experience
         in financial and business matters that Purchaser is capable of
         evaluating the merits and risks of the investment in the Senior
         Preferred Stock. The Purchaser is an "accredited investor" as that term
         is defined in Rule 501 under Regulation D promulgated under the
         Securities Act.

                  4.4      No Reliance on Seller Regarding Investment. Purchaser
         acknowledges that Purchaser is making an independent investment
         decision based upon Purchaser's own gathering of information and
         analysis thereof, and is not relying upon information or analysis from
         Seller or upon any recommendation from Seller, with respect to the
         purchase of the Senior Preferred Stock. In this regard, Purchaser has
         independently obtained, reviewed and understands the designations,
         rights and preferences currently on file with the Texas Secretary of
         State applicable to the Senior Preferred Stock. Purchaser also
         understands that certain rights, duties and obligations contained in
         such designations by, or on behalf of WEDGE will not be applicable to
         Purchaser, and Purchaser has obtained Purchaser's own independent legal
         counsel to assist in analyzing same.

                  4.5      Restricted Securities. Purchaser understands that the
         Senior Preferred Stock may not be sold, transferred or otherwise
         disposed of without registration under the Securities Act of 1933
         ("Securities Act") or an exemption from such registration requirement,
         and that absent an effective registration statement covering the Senior
         Preferred Stock or an available exemption from registration under the
         Securities Act, the Securities must be held indefinitely. Furthermore,
         the Purchaser understands that the Senior Preferred Stock is being
         acquired from an "Affiliate" of the Company, as that term is defined
         under the Securities Act, and as such certain additional limitations on
         resale may be applicable to the Senior Preferred Stock or any shares
         convertible therefrom.

                  4.6      Legend. The certificate representing the Senior
         Preferred Stock which Purchaser will receive shall be endorsed with the
         legends set forth below, and Purchaser agrees that, except to the
         extent such restrictions are waived by the Company, Purchaser shall not
         transfer the Senior Preferred Stock without complying with the
         restrictions on transfer described in the first such legend set forth
         below:

                                                                          Page 4



                  THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE BEEN
                  ACQUIRED FOR INVESTMENT ONLY AND HAVE NOT BEEN REGISTERED
                  UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE
                  SECURITIES LAWS OF ANY STATE. WITHOUT SUCH REGISTRATION, SUCH
                  SECURITIES MAY NOT BE SOLD OR OTHERWISE TRANSFERRED AT ANY
                  TIME WHATSOEVER, EXCEPT UPON DELIVERY TO THE CORPORATION OF AN
                  OPINION OF COUNSEL SATISFACTORY TO THE CORPORATION THAT
                  REGISTRATION IS NOT REQUIRED FOR SUCH TRANSFER OR THE
                  SUBMISSION TO THE CORPORATION OF SUCH OTHER EVIDENCE AS MAY BE
                  SATISFACTORY TO THE CORPORATION TO THE EFFECT THAT ANY SUCH
                  TRANSFER SHALL NOT BE IN VIOLATION OF THE SECURITIES ACT OF
                  1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS OR ANY
                  RULE OR REGULATION PROMULGATED THEREUNDER.

                  THE SECURITIES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO
                  CERTAIN DESIGNATIONS, RIGHTS AND PREFERENCES AS SET FORTH IN
                  THE STATEMENT OF RESOLUTION ESTABLISHING THE 8-1/2% SENIOR
                  CONVERTIBLE PREFERRED STOCK, AS AMENDED, OF TGC INDUSTRIES,
                  INC. ON FILE WITH THE SECRETARY OF STATE OF THE STATE OF
                  TEXAS.

         5.       Miscellaneous.

                  5.1      Successors and Assigns. The terms and conditions of
         this Agreement shall inure to the benefit of and be binding upon the
         respective successors and assigns of the parties.

                  5.2      Governing Law; Venue. This Agreement shall be
         governed by and construed under the laws of the State of Texas, without
         giving effect to the conflicts of laws provisions thereof, and venue
         for the resolution of any disputes hereunder shall be had in the state
         and federal courts located in Tarrant County, Texas.

                  5.3      Counterparts. This Agreement may be executed in two
         or more counterparts, each of which shall be deemed an original, and
         all of which together shall constitute one and the same instrument.

                  5.4      Entire Agreement; Amendments and Waivers. This
         Agreement contains the entire agreement of the parties hereto with
         respect to the subject matter hereof, and any term in this Agreement
         may be amended, and the observance of any term in this Agreement may be
         waived, only by an instrument in writing.

                  5.5      Survival of Representations and Warranties. The
         representations and warranties of the parties hereto contained in this
         Agreement or in any writing

                                                                          Page 5



         delivered pursuant hereto or at the Closing, shall survive the Closing
         and the consummation of the transactions contemplated hereby (and any
         examination or investigation by or on behalf of any party hereto) until
         the second anniversary of the Closing date.

         IN WITNESS WHEREOF, each of the parties hereto has executed this
Agreement, or has caused this Agreement to be executed on its behalf by a
representative duly authorized, as of the date first above set forth.

                                     SELLER

                                     WEDGE ENERGY SERVICES, L.L.C.

                                     By: _______________________________________
                                     Name: _____________________________________
                                     Title: ____________________________________

                                     PURCHASER

                                     ___________________________________________

                                     By: _______________________________________
                                     Name: _____________________________________
                                     Title: ____________________________________

Number of Shares of Senior Preferred Stock
purchased pursuant to this Agreement:                        __________________

Purchase Price: ($0.53 per Share)                            $_________________

                                                                          Page 6



                                                                     EXHIBIT (b)

                              TGC INDUSTRIES, INC.
                                ESCROW AGREEMENT

         This ESCROW AGREEMENT ("Escrow Agreement") is made and entered into
effective as of the 12th day of February, 2004, by and among WEDGE Energy
Services, L.L.C., a Delaware limited liability company (the "Seller" or
"WEDGE"), the undersigned purchaser from Seller as set forth on the signature
page hereof (the "Purchaser"), Barrett Gardner Associates, Inc., a New Jersey
corporation ("Barrett Gardner") and Law, Snakard & Gambill, P.C., a Texas
Professional Corporation (the "Escrow Agent").

         WHEREAS, the Seller and Purchaser have entered into that certain
Preferred Stock Purchase Agreement dated February 12, 2004 (the "Preferred Stock
Purchase Agreement") providing for the sale by Seller of shares of its 8-1/2%
Senior Convertible Preferred Stock (the "Senior Preferred Stock") of TGC
Industries, Inc., a Texas corporation (the "Company") in accordance with the
terms thereof, which terms provide that the Closing thereunder is conditioned on
and will be simultaneous with the Closing of the sale to a number of purchasers
of all of Seller's 3,024,264 shares of Senior Preferred Stock pursuant to
preferred stock purchase agreements of like tenor to the Preferred Stock
Purchase Agreement;

         WHEREAS, the Preferred Stock Purchase Agreement requires this Escrow
Agreement with the Escrow Agent for the deposit of and maintenance of funds
("Escrow Funds") received from Purchaser and for the deposit and maintenance of
certificates representing shares of Senior Preferred Stock ("Escrow Shares")
received from Seller, pending the Closing under the Preferred Stock Purchase
Agreement; and

         WHEREAS, that certain Financial Advisory Services Agreement dated
February 12, 2004 (the "Financial Advisory Agreement") between Barrett Gardner
and Seller, requires this Escrow Agreement with the Escrow Agent for the deposit
and maintenance of funds in the amount of $102,860 (the "Advisory Fee Funds")
and 17,304 shares of Common Stock of the Company (the "Advisory Fee Shares")
received from Seller, pending the Closing under the Preferred Stock Purchase
Agreement

         WHEREAS, the Escrow Agent has agreed to open and maintain an escrow
account in accordance with the terms of this Agreement;

         NOW, THEREFORE, in consideration of the mutual covenants herein
contained, the parties hereto hereby agree as follows:

         1.       Appointment of Escrow Agent. The Seller and Purchaser hereby
appoint the Escrow Agent to act in accordance with and subject to the terms of
this Agreement, and the Escrow Agent hereby accepts such appointment and agrees
to act in accordance with and subject to such terms.



         2.       Escrow Account. Escrow Agent agrees to maintain an escrow
account (the "Escrow Account") in accordance wit the terms of this Agreement.
Escrow Agent further agrees that the Escrow Funds and the Escrow Shares placed
into such Escrow Account, as well as the Advisory Fee Funds and the Advisory Fee
Shares, will be held and disposed of in accordance with the terms of this
Agreement.

         3.       Deposit of Escrow Funds and Escrow Shares. In accordance with
the terms of the Preferred Stock Purchase Agreement: (a) Purchaser shall
promptly deliver the Purchase Price for the Senior Preferred Stock, in cash by
wire transfer or delivery of Purchaser's check, to Escrow Agent, which Escrow
Agent shall deposit in the Escrow Account, and (b) Seller shall promptly deliver
certificates representing the shares of Senior Preferred Stock, duly endorsed
for transfer or accompanied by stock powers for transfer, which Escrow Agent
shall hold in escrow. The Escrow Agent shall maintain the Escrow Account as an
account which can be drawn upon at any time. The Escrow Agent agrees that the
Escrow Funds and the Escrow Shares will be held and maintained by the Escrow
Agent for the exclusive benefit of the Purchaser and the Seller in accordance
with the terms and provisions of this Escrow Agreement.

         4.       Deposit of Advisory Fee Funds and Advisory Fee Shares. In
accordance with the terms of the Financial Advisory Services Agreement, Seller
shall promptly deliver the Advisory Fee Funds to Escrow Agent, which Escrow
Agent shall deposit in the Escrow Account, and Seller shall promptly deliver
certificates representing the Advisory Fee Shares duly endorsed for transfer or
accompanied by stock powers for transfer, which Escrow Agent shall hold in
escrow. The Escrow Agent shall maintain the Escrow Account as an account which
can be drawn upon at any time. The Escrow Agent agrees that the Advisory Fee
Funds and the Advisory Fee Shares will be held and maintained by the Escrow
Agent for the exclusive benefit of Barnett Gardner and the Seller in accordance
with the terms and provisions of this Escrow Agreement.

         5.       Disbursement from the Escrow Account. Upon satisfaction of the
conditions set forth below, Escrow Agent shall disburse (the "Closing
Disbursement"): (a) the Escrow Funds, without interest, by wire transfer to
Seller; (b) the Escrow Shares by delivery of certificate(s) registered in
Purchaser's name for the number of shares purchased by Purchaser under the
Preferred Stock Purchase Agreement to Purchaser; (c) the Advisory Fee Funds,
without interest, by wire transfer to Barrett Gardner; and (d) the Advisory Fee
Shares by delivery of certificate(s) registered in Barrett Gardner's name to
Barrett Gardner. The conditions which must be satisfied for Escrow Agent to make
the Closing Disbursement are as follows: (w) Escrow Agent shall be in receipt of
Escrow Funds from Purchaser and from all purchasers under preferred stock
purchase agreements of like tenor to Purchaser's in the aggregate amount of One
Million Six Hundred Two Thousand Eight Hundred Sixty Dollars ($1,602,860.00)
(representing $0.53 per share of Senior Preferred Stock) in immediately
available funds; (x) Escrow Agent shall be in receipt of the Escrow Shares from
Seller representing all of Seller's 3,024,264 shares of Senior Preferred Stock
duly endorsed for transfer or accompanied by stock powers for transfer; (y)
Escrow Agent shall be in receipt of the Advisory Fee Funds from Seller in the
amount of One Hundred Two Thousand Eight Hundred Sixty Dollars ($102,860.00) in
immediately available funds; and (z) Escrow Agent shall be in receipt of the
Advisory Fee Shares from Seller representing 17,304 shares of Common Stock of
the Company duly

                                                                          Page 2



endorsed for transfer or accompanied by stock powers for transfer. In the event
that all of the above conditions to the Closing Disbursement have not occurred
within thirty (30) days from the date of this Escrow Agreement, Escrow Agent
return: (A) the Escrow Funds, without interest, to Purchaser; (B) the Escrow
Shares to Seller; (C) the Advisory Fee Funds, without interest, to Seller, and
(D) the Advisory Fee Shares to Seller (the "Return Disbursement"). Upon
occurrence of either the Closing Disbursement or the Return Disbursement, the
Escrow Agent shall be released from further obligation or liability hereunder.

         6.       Concerning the Escrow Agent.

         6.1      The Escrow Agent shall not be liable for any action taken or
omitted by it, or any action suffered by it to be taken or omitted, in good
faith and in the exercise of its own best judgment, and may rely conclusively
and shall be protected in acting upon any order, notice, demand, certificate,
opinion or advice of counsel (including counsel chosen by the Escrow Agent),
statement, instrument, report or other paper or document (not only as to its due
execution and the validity and effectiveness of its provisions, but also as to
the truth and acceptability, of any information therein contained) which is
believed by the Escrow Agent to be genuine and to be signed or presented by the
proper person or persons. The Escrow Agent shall not be bound by any notice or
demand, or any waiver, modification, termination or rescission of this Agreement
unless evidenced by a writing delivered to the Escrow Agent signed by the proper
party or parties and, if the duties or rights of the Escrow Agent are affected,
unless it shall have given its prior written consent thereto;

         6.2      The Escrow Agent shall not be responsible for the sufficiency
or accuracy, the form of, or the execution, validity, value or genuineness of,
any document or property received, held or delivered by it hereunder, or of any
signature or endorsement thereon, or for any lack of endorsement thereon, or for
any description therein, nor shall the Escrow Agent be responsible or liable in
any respect on account of the identity, authority or rights of the persons
executing or delivering or purporting to execute or deliver any document or
property paid or delivered by the Escrow Agent pursuant to the provisions
hereof. The Escrow Agent shall not be liable for any loss which may be incurred
by reason of any investment of any monies or properties which it holds
hereunder.

         6.3      The Escrow Agent shall have the right to assume in the absence
of written notice to the contrary from the proper person or persons that a fact
or an event by reason of which an action would or might be taken by the Escrow
Agent does not exist or has not occurred, without incurring liability for any
action taken or omitted, in good faith and in the exercise of its own best
judgment, in reliance upon such assumption.

         6.4      The Escrow Agent shall be indemnified and held harmless by the
Seller, Purchaser and Barrett Gardner from and against any expenses, including
counsel fees and disbursements, or loss suffered by the Escrow Agent in
connection with any action, suit or other proceeding involving any claim, or in
connection with any claim or demand, which in any way directly or indirectly,
arises out of or relates to this Agreement, the services of the Escrow Agent
hereunder, the monies or other property held by it hereunder or any such expense
or loss. Promptly after the receipt by the Escrow Agent of notice of any demand
or claim or the commencement of any action, suit or proceeding, the

                                                                          Page 3



Escrow Agent shall, if a claim in respect thereof shall be made against a party
hereto, notify the appropriate party thereof in writing; but the failure by the
Escrow Agent to give such notice shall not relieve such party from any liability
which such party may have to the Escrow Agent hereunder. In the event of the
receipt of such notice, the Escrow Agent, in its sole discretion, may commence
an action in the nature of interpleader in an appropriate court to determine
ownership or disposition of the Escrow Funds or it may deposit the Escrow Funds
with the clerk of any appropriate court or it may retain the Escrow Funds
pending receipt of a final, non-appealable order of a court having jurisdiction
over the parties hereto directing to whom and under what circumstances the
Escrow Funds are to be disbursed and delivered.

         6.5      The Escrow Agent shall maintain the Escrow Account as an
account which can be drawn upon at any time. The Escrow Agent agrees that the
Escrow Funds, the Escrow Shares, the Advisory Fee Funds, and the Advisory Fee
Shares will be held and maintained by the Escrow Agent for the exclusive benefit
of the Purchaser, the Seller and Barrett Gardner in accordance with the terms
and provisions of this Escrow Agreement. The Escrow Agent shall be entitled to
reimbursement from the Seller, Purchaser and Barrett Gardner for all accountable
expenses paid or incurred by the Escrow Agent in the administration of its
duties hereunder, if any.

         6.6      From time to time on and after the date hereof, Seller,
Purchaser, and Barrett Gardner shall deliver or cause to be delivered to the
Escrow Agent such further documents and instruments and shall do or cause to be
done such further acts as the Escrow Agent shall reasonably request (it being
understood that the Escrow Agent shall have no obligation to make such request)
to carry out more effectively the provisions and purposes of this Agreement, to
evidence compliance herewith or to assure itself that it is protected in acting
hereunder.

         6.7      The Escrow Agent may resign at any time and be discharged from
its duties as escrow agent hereunder by its giving the parties hereto at least
thirty (30) days prior written notice thereof. As soon as practicable after its
resignation, the Escrow Agent shall turn over to a successor escrow agent
appointed by the parties hereto, all monies and property held hereunder upon
presentation of the document appointing the new escrow agent and its acceptance
thereof. If no new agent is so appointed within the sixty (60) day period
following the giving of such notice of resignation, the Escrow Agent may deposit
the monies and property held hereunder with any court it deems appropriate.

         6.8      The Escrow Agent shall resign and be discharged from its
duties as escrow agent hereunder if so requested in writing at anytime by the
parties hereto, provided, however, that such resignation shall become effective
only upon acceptance of appointment by a successor escrow agent as provided in
paragraph 6.7.

         6.9      Notwithstanding anything herein to the contrary, the Escrow
Agent shall not be relieved from liability hereunder for its own gross
negligence or its own willful misconduct.

                                                                          Page 4



         7.       Miscellaneous.

         7.1      This Agreement shall for all purposes be deemed to be made
under and shall be construed in accordance with the laws of the State of Texas,
without giving effect to the conflicts of laws provisions thereof, and venue for
the resolution of any disputes hereunder shall be had in the state and federal
courts located in Tarrant County, Texas.

         7.2      This Agreement contains the entire agreement of the parties
hereto with respect to the subject matter hereof and, except as expressly
provided herein, may not be changed or modified except by an instrument in
writing signed by the party to be charged.

         7.3      This Agreement may be executed in multiple counterparts, each
of which shall be deemed an original, and all of which together shall constitute
one and the same instrument.

         7.4      This Agreement shall be binding upon and inure to the benefit
of the respective parties hereto and their legal representatives, successors and
assigns.

         7.5      Any notice or other communication required or which may be
given hereunder shall be in writing and either be delivered personally or be
mailed, certified or registered mail, return receipt requested, postage prepaid,
and shall be deemed given when so delivered personally or, if mailed, two (2)
business days after the date of mailing as follows:

If to the Seller, to:              if to the Purchaser, to:
WEDGE Energy Services, L.L.C.      To the address set forth below Purchaser's
1415 Louisiana, Suite 3000         signature on the signature page hereof
Houston, Texas 77002
Attn: Richard Blohm

if to Barrett Gardner, to:         and if to the Escrow Agent, to:
Barrett Gardner Associates, Inc.   Law, Snakard & Gambill, P.C.
636 River Road                     1600 West 7th Street, Suite 500
Fair Haven, New Jersey 07704       Fort Worth, Texas 76102
Attn: William Barrett              Attn: Vernon E. Rew, Jr., Shareholder

                                                                          Page 5



         The parties may change the persons and addresses to which the notices
         or other communications are to be sent by giving written notice of any
         such change in the manner provided herein for giving notice.

         IN WITNESS WHEREOF, each of the parties has executed this Escrow
Agreement, as of the dated above set forth.

SELLER                             BARRETT GARDNER

WEDGE ENERGY SERVICES, L.L.C.      BARRETT GARDNER ASSOCIATES, INC.

By: ____________________________   By: ________________________________________
Name: __________________________   Name: William J. Barrett
Title: _________________________   Title: President

PURCHASER                          ESCROW AGENT

________________________________   LAW, SNAKARD & GAMBILL, P.C.

By: ____________________________   By: ________________________________________
Name: __________________________   Name: Vernon E. Rew, Jr.
Title: _________________________   Title: Shareholder

PURCHASER'S ADDRESS

_________________________________
_________________________________
_________________________________

                                                                          Page 6



                                                                     EXHIBIT (c)

                               FINANCIAL ADVISORY
                               SERVICES AGREEMENT

         THIS FINANCIAL ADVISORY SERVICES AGREEMENT (the "FINANCIAL ADVISORY
AGREEMENT") is made and entered into as of the 12th day of February, 2004, by
and among WEDGE ENERGY SERVICES, L.L.C., a Delaware limited liability company
(the "Seller" or "WEDGE") and BARRETT GARDNER ASSOCIATES, INC., a New Jersey
corporation ("BARRETT GARDNER").

         WHEREAS, contemporaneously herewith, the Seller is entering into that
certain Preferred Stock Purchase Agreement dated February 12, 2004 (the
"Preferred Stock Purchase Agreement") with a number of purchasers providing for
the sale (the "Transaction") by Seller of all of its 3,024,264 shares of 8.5%
Senior Convertible Preferred Stock (the "Senior Preferred Stock") of TGC
Industries, Inc., a Texas corporation (the "Company");

         WHEREAS, Seller and Barrett Gardner desire to enter into this Financial
Advisory Agreement for Barrett Gardner to provide certain financial advisory
services in assisting WEDGE in connection with the sale by WEDGE of its Senior
Preferred Stock, under the terms and conditions set forth herein.

         NOW, THEREFORE, in consideration of the mutual covenants herein
contained, the parties hereto hereby agree as follows:

         1.       Engagement of Barrett Gardner. WEDGE hereby retains Barrett
Gardner to provide certain financial advisory services to assist WEDGE in
connection with the Transaction and Barrett Gardner hereby accepts such
engagement and the parties agree to act in accordance with and subject to the
terms of this Agreement.

         2.       Financial Advisory Services Fees. In consideration for the
provision of the financial advisory services by Barrett Gardner to WEDGE in
connection with the Transaction, WEDGE hereby agrees to make payment of and to
deliver to Barrett Gardner at the Closing (as defined in the Preferred Stock
Purchase Agreement) the cash sum of One Hundred Two Thousand Eight Hundred Sixty
Dollars ($102,860.00) (the "Advisory Fee Funds") and 17,304 shares of Common
Stock of the Company (the "Advisory Fee Shares"). It is understood and agreed by
Seller and Barrett Gardner that Seller will make delivery of the Advisory Fee
Funds and Advisory Fee Shares pursuant to an Escrow Agreement entered into
contemporaneously herewith between Seller, the purchasers of Seller's Senior
Preferred Stock, Barrett Gardner, and Law, Snakard & Gambill, P.C. as Escrow
Agent. At the Closing the Advisory Fee Funds and the Advisory Fee Shares will be
delivered in accordance with the terms of the Escrow Agreement. In the event the
Closing does not occur, the Advisory Fee Funds and the Advisory Fee Shares will
be returned to WEDGE in accordance with the terms of the Escrow Agreement.

                                                                          Page 1



         3.       Title. Seller hereby represents and warrants to Barrett
Gardner that Seller is the record and beneficial owner of the Advisory Fee
Shares and has good title to the Advisory Fee Shares, and upon the transfer and
delivery to Barrett Gardner of the Advisory Fee Shares at the Closing, Barrett
Gardner will obtain good title to such Advisory Fee Shares, free and clear of
all liens, encumbances, security and interests, exceptions or claims of any
nature whatsoever.

         4.       Acquisition for Own Account. Barrett Gardner hereby represents
and warrants to Seller that it will acquire the Advisory Fee Shares for its own
account, not as nominee or agent, and not with a view toward the resale or
distribution of any part thereof. Furthermore, Barrett Gardner represents that
it is experienced in evaluating and investing in securities and acknowledges
that it is able to fend for itself, can bear the economic risk of the
investment, and has such knowledge and experience in financial and business
matters that it is capable of evaluating the merits and risks of the acquisition
of the Advisory Fee Shares.

         5.       Miscellaneous.

         5.1      This Advisory Services Agreement shall for all purposes be
deemed to be made under and shall be construed in accordance with laws of the
State of Texas.

         5.2      This Advisory Services Agreement contains the entire agreement
of the parties hereto with respect to the subject matter hereof and, except as
expressly provided herein, may not be changed or modified except by an
instrument in writing signed by the party to be charged.

         5.3      This Agreement may be executed in two or more counterparts,
each of which shall be deemed an original, and all of which together shall
constitute one and the same instrument.

         5.4      This Advisory Services Agreement shall be binding upon and
inure to the benefit of the respective parties hereto and any legal
representatives, successors and assigns.

         IN WITNESS WHEREOF, each of the parties hereto has executed this
Advisory Services Agreement, as of the date above set forth.

SELLER                                             BARRETT GARDNER

WEDGE ENERGY SERVICES, L.L.C.              BARRETT GARDNER ASSOCIATES, INC.

By: ______________________________         By: _________________________________
Name: ____________________________         Name: _______________________________
Title: ___________________________         Title: ______________________________

                                                                          Page 2


                                                                               .
                                                                               .
                                                                               .

                                  EXHIBIT 7(d)

PREFERRED STOCK PURCHASERS: SHARES PURCHASED: - ------------------------------------------------ ----------------- Nicholas A. Baker, III 113,200 William J. Barrett, Jr. 169,800 William J. Barrett MPPP 709,200 Sara Barrett MPPP 75,500 Robert J. Deputy 34,000 Jason M. Elsas, Jr. 235,800 Leona T. Flynn 188,500 Arthur J. Gajarsa and Melanie Gajarsa, JTWROS 47,100 Herbert M. Gardner 188,500 Mary Gardner 47,000 Stuart M. Gerson and Pamela E. Somers, JTWROS 83,000 Ann C Green Roth IRA (452-95081-1-3) 9,664 William C. Hurtt, Jr. - GST Exempt (10263619843) 375,000 William D. Marohn 60,000 Allen T. McInnes & Doris C. McInnes, JTWROS 188,500
LIST OF PURCHASERS CONTINUED ON FOLLOWING PAGE EXHIBIT 7(d) (CONT'D FROM PREVIOUS PAGE)
PREFERRED STOCK PURCHASERS: SHARES PURCHASED: - ------------------------------------------------ ----------------- Ellen M. Noreen & Clifford M. Noreen, JTWROS 47,000 C. Richard Stafford, MPPP (452-95084-1-0) 34,000 Sidney Todres IRA Rollover (47V088572) 300,000 Technology Insurance Company, Inc. 59,250 Rochdale Insurance Company 59,250 Total Preferred Stock Shares Purchased: 3,024,264 ------------- Total Consideration: $1,602,859.92 =============
COMMON STOCK SHARES TRANSFERRED: ------------------- Bennett Gardner Associates, Inc. 17,304 --------- Transferred as consideration for services rendered: 17,304 --------- Total Common Shares assuming full conversion of preferred 3,041,568 =========


                                                                     EXHIBIT (e)

                                POWER OF ATTORNEY

         The undersigned does hereby make, constitute and appoint William H.
White and Richard E. Blohm, Jr., and each of them severally, the undersigned's
true and lawful attorney or attorneys (hereinafter referred to individually as
"Attorney" or collectively as "Attorneys") with power to act for the undersigned
and in the undersigned's name, place and stead, with or without the other and
with full power of substitution and resubstitution, for the sole purpose of
executing, making, declaring, certifying and filing on behalf of the undersigned
with the Securities and Exchange Commission, and other appropriate governmental
or private entities, any and all statements, reports and other information
required to be filed by the undersigned under the Securities Exchange Act of
1934, as amended, or other state or federal statutes, by virtue of or relating
to the undersigned's beneficial ownership of voting securities of TGC
Industries, Inc. (the "Company"), including without limitation any Schedule 13D,
any and all amendments to any such schedule, any Joint Filing Agreement and any
and all amendments thereto, and all other documents and information incidental
or related thereto required to be executed, made or filed by the undersigned, in
the form and manner in which such Attorneys or any of them deem necessary,
appropriate, convenient or desirable to be done pursuant to and in accordance
with the authorization contained in this Power of Attorney, as fully and to all
intents and purposes as the undersigned might or could do in person, the
undersigned hereby ratifying and approving the acts of the Attorneys and each of
them.

         IN WITNESS WHEREOF, the undersigned has execute this Power of Attorney
on December 17, 1999.

                                                     /s/ Issam M. Fares
                                                     -------------------
                                                     Issam M. Fares



                                  EXHIBIT 7(f)

                             JOINT FILING AGREEMENT

         The undersigned each agree that the Statement on Schedule 13D relating
to the Common Stock, $.30 par value, of TGC Industries, Inc. is adopted and
filed on behalf of each of them, (ii) all future amendments to such Statement on
Schedule 13D will, unless written notice to the contrary is delivered as
described below, be jointly filed on behalf of each of them, and (iii) the
provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934 apply to
each of them. This agreement may be terminated with respect to the obligation to
jointly file future amendments to such Statement on Schedule 13D as to any of
the undersigned upon such person giving written notice thereof to the other
person signatory hereto, at the principal office thereof.

         IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing
Agreement as of the date set forth below.

Dated: February 17, 2004              WEDGE Energy Services, L.L.C.

                                      By /s/ JAMES F. TIDWELL
                                        ------------------------------------
                                      Name: James F. Tidwell
                                      Title: Vice President

Dated: February 17, 2004              ISSAM M. FARES

                                      By /s/ RICHARD E. BLOHM, JR.
                                        ------------------------------------
                                      Name: Richard E. Blohm, Jr.
                                      Title: Attorney-in-Fact