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         THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUED UPON ITS
                 EXERCISE ARE SUBJECT TO THE RESTRICTIONS ON
               TRANSFER SET FORTH IN SECTION 4 OF THIS WARRANT
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Warrant No.                                            Number of Shares:
                                                       (subject to adjustment)
Date of Issuance:       May 17, 1993


                           FIRST SEISMIC CORPORATION

                         COMMON STOCK PURCHASE WARRANT

                           (Void after June 1, 2000)


        First Seismic Corporation, a Delaware corporation (the "Company"), for
value received, hereby certifies that           or his, her or its registered
assigns (the "Registered Holder"), is entitled, subject to the terms set
forth below, to purchase from the Company, at any time or from time to time
on or after the date of issuance and on or before June 1, 2000 at not later
than 5:00 p.m. (Houston, Texas time),         shares of Common Stock, $ .01 par
value per share, of the Company, at a purchase price of $.50 per share. The
shares purchasable upon exercise of this Warrant, and the purchase price per
share, each as adjusted from time to time pursuant to the provisions of this
Warrant, are hereinafter referred to as the "Warrant Shares" and the
"Purchase Price," respectively.

        1.      EXERCISE.

                (a) This Warrant may be exercised by the Registered Holder, in
whole or in part, by surrendering this Warrant, with the purchase form appended
hereto as EXHIBIT I duly executed by such Registered Holder or by such
Registered Holder's duly authorized attorney, at the principal office of the
Company, or at such other office or agency as the Company may designate,
accompanied by payment in full, in lawful money of the United States, of the
Purchase Price payable in respect of the number of Warrant Shares purchased upon
such exercise.

                (b) Each exercise of this Warrant shall be deemed to have been
effected immediately prior to the close of business on the day on which this
Warrant shall have been surrendered to the Company as provided in subsection
1(a) above. At such time, the


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person or persons in whose name or names any certificates for Warrant Shares
shall be issuable upon such exercise as provided in subsection 1(d) below
shall be deemed to have become the holder or holders of record of the Warrant
Shares represented by such certificates.

                (c) As soon as practicable after the exercise of this Warrant in
full or in part, and in any event within 10 days thereafter, the Company, at its
expense, will cause to be issued in the name of, and delivered to, the
Registered Holder, or as such Holder (upon payment by such Holder of any
applicable transfer taxes) may direct:

                    (i) a certificate or certificates for the number of full
Warrant Shares to which such Registered Holder shall be entitled upon such
exercise plus, in lieu of any fractional share to which such Registered Holder
would otherwise be entitled, cash in an amount determined pursuant to Section 3
hereof; and

                    (ii) in case such exercise is in part only, a new warrant
or warrants (dated the date hereof) of like tenor, calling in the aggregate
on the face or faces thereof for the number of Warrant Shares equal (without
giving effect to any adjustment therein) to the number of such shares called
for on the face of this Warrant minus the number of such shares purchased by
the Registered Holder upon such exercise.

        2.      ADJUSTMENTS.

                (a) If outstanding shares of the Company's Common Stock shall be
subdivided into a greater number of shares or a dividend in Common Stock shall
be paid in respect of Common Stock, the Purchase Price in effect immediately
prior to such subdivision or at the record date of such dividend shall
simultaneously with the effectiveness of such subdivision or immediately after
the record date of such dividend be proportionately reduced. If outstanding
shares of Common Stock shall be combined into a smaller number of shares, the
Purchase Price in effect immediately prior to such combination shall,
simultaneously with the effectiveness of such combination, be proportionately
increased. When any adjustment is required to be made in the Purchase Price, the
number of Warrant Shares purchasable upon the exercise of this Warrant shall be
changed to the number determined by dividing (i) an amount equal to the number
of shares issuable upon the exercise of this Warrant immediately prior to such
adjustment, multiplied by the Purchase Price in effect immediately prior to such
adjustment, by (ii) the Purchase Price in effect immediately after such
adjustment.


                                      -2-

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                (b) If there shall occur any capital reorganization or
reclassification of the Company's Common Stock (other than a change in par value
or a subdivision or combination as provided for in subsection 2(a) above), or
any consolidation or merger of the Company with or into another corporation, or
a transfer of all or substantially all of the assets of the Company, then, as
part of any such reorganization, reclassification, consolidation, merger or
sale, as the case may be, lawful provision shall be made so that the Registered
Holder of this Warrant shall have the right thereafter to receive upon the
exercise hereof the kind and amount of shares of stock or other securities or
property which such Registered Holder would have been entitled to receive if,
immediately prior to any such reorganization, reclassification, consolidation,
merger or sale, as the case may be, such Registered Holder had held the number
of shares of Common Stock which were then purchasable upon the exercise of this
Warrant. In any such case, appropriate adjustment (as reasonably determined in
good faith by the Board of Directors of the Company) shall be made in the
application of the provisions set forth herein with respect to the rights and
interests thereafter of the Registered Holder of this Warrant, such that the
provisions set forth in this Section 2 (including provisions with respect to
adjustment of the Purchase Price) shall thereafter be applicable, as nearly as
is reasonably practicable, in relation to any shares of stock or other
securities or property thereafter deliverable upon the exercise of this Warrant.

                (c) When any adjustment is required to be made in the Purchase
Price, the Company shall promptly mail to the Registered Holder a certificate
setting forth the Purchase Price after such adjustment and setting forth a brief
statement of the facts requiring such adjustment. Such certificate shall also
set forth the kind and amount of stock or other securities or property into
which this Warrant shall be exercisable following the occurrence of any of the
events specified in subsection 2(a) or (b) above.

        3.      FRACTIONAL SHARES. The Company shall not be required upon the
exercise of this Warrant to issue any fractional shares, but shall make an
adjustment therefor in cash on the basis of the fair market value per share of
Common Stock, as determined by the Company's Board of Directors.

        4.      REQUIREMENTS FOR TRANSFER.

                (a) This Warrant and the Warrant Shares shall not be sold or
transferred unless either (i) they first shall have been registered under the
Securities Act of 1933, as amended (the "Act"), or (ii) the Company first shall
have been furnished with


                                      -3-

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an opinion of legal counsel, reasonably satisfactory to the Company, to the
effect that such sale or transfer is exempt from the registration
requirements of the Act.

                (b) Notwithstanding the foregoing, no registration or opinion of
counsel shall be required for (i) a transfer by a Registered Holder which is a
partnership to a partner of such partnership or a retired partner of such
partnership who retires after the date hereof, or to the estate of any such
partner or retired partner, if the transferee agrees in writing to be subject to
the terms of this Section 4, or, (ii) a transfer made in accordance with Rule
144 under the Act.

                (c) Each certificate representing Warrant Shares shall bear a
legend substantially in the following form:

                "The securities represented by this certificate have not been
                registered under the Securities Act of 1933, as amended, and may
                not be offered, sold or otherwise transferred, pledged or
                hypothecated unless and until such securities are registered
                under such Act or an opinion of counsel satisfactory to the
                Company is obtained to the effect that such registration is not
                required."

The foregoing legend shall be removed from the certificates representing any
Warrant Shares, at the request of the holder thereof, at such time as they
become eligible for resale pursuant to Rule 144(k) under the Act.

        5.      NO IMPAIRMENT. The Company will not, by amendment of its charter
or through reorganization, consolidation, merger, dissolution, sale of assets or
any other voluntary action, avoid or seek to avoid the observance or performance
of any of the terms of this Warrant, but will at all times in good faith assist
in the carrying out of all such terms and in the taking of all such action as
may be necessary or appropriate in order to protect the rights of the holder of
this Warrant against impairment.

        6.      LIQUIDATING DIVIDENDS. If the Company pays a dividend or makes a
distribution on the Common Stock payable otherwise than in cash out of earnings
or earned surplus (determined in accordance with generally accepted accounting
principles) except for a stock dividend payable in shares of Common Stock (a
"Liquidating Dividend"), then the Company will pay or distribute to the
Registered Holder of this Warrant, upon the exercise


                                      -4-

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hereof, in addition to the Warrant Shares purchased upon such exercise, the
Liquidating Dividend which would have been paid to such Registered Holder if
he had been the owner of record of such Warrant Shares immediately prior to
the date on which a record is taken for such Liquidating Dividend or, if no
record is taken, the date as of which the record holders of Common Stock
entitled to such dividends or distribution are to be determined.

        7.      NOTICES OF RECORD DATE, ETC. In case:

                (a) the Company shall take a record of the holders of its Common
Stock (or other stock or securities at the time deliverable upon the exercise of
this Warrant) for the purpose of entitling or enabling them to receive any
dividend or other distribution, or to receive any right to subscribe for or
purchase any shares of stock of any class or any other securities, or to receive
any other right; or

                (b) of any capital reorganization of the Company, any
reclassification of the capital stock of the Company, any consolidation or
merger of the Company with or into another corporation (other than a
consolidation or merger in which the Company is the surviving entity), or any
transfer of all or substantially all of the assets of the Company; or

                (c) of the voluntary or involuntary dissolution, liquidation or
winding-up of the Company,

then, and in each such case, the Company will mail or cause to be mailed to the
Registered Holder of this Warrant a notice specifying, as the case may be, (i)
the date on which a record is to be taken for the purpose of such dividend,
distribution or right, and stating the amount and character of such dividend,
distribution or right, or (ii) the effective date on which such reorganization,
reclassification, consolidation, merger, transfer, dissolution, liquidation or
winding-up is to take place, and the time, if any is to be fixed, as of which
the holders of record of Common Stock (or such other stock or securities at the
time deliverable upon the exercise of this Warrant) shall be entitled to
exchange their shares of Common Stock (or such other stock or securities) for
securities or other property deliverable upon such reorganization,
reclassification, consolidation, merger, transfer, dissolution, liquidation or
winding-up. Such notice shall be mailed at least ten (10) days prior to the
record date or effective date for the event specified in such notice.

        8.      RESERVATION OF STOCK. The Company will at all times reserve and
keep available, solely for issuance and delivery upon


                                     -5-

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the exercise of this Warrant, such number of Warrant Shares and other stock,
securities and property, as from time to time shall be issuable upon the
exercise of this Warrant.

        9.      EXCHANGE OF WARRANTS. Upon the surrender by the Registered
Holder of any Warrant or Warrants, properly endorsed, to the Company at the
principal office of the Company, the Company will, subject to the provisions of
Section 4 hereof, issue and deliver to or upon the order of such Holder, at the
Company's expense, a new Warrant or Warrants of like tenor, in the name of such
Registered Holder or as such Registered Holder (upon payment by such Registered
Holder of any applicable transfer taxes) may direct, calling in the aggregate on
the face or faces thereof for the number of shares of Common Stock called for on
the face or faces of the Warrant or Warrants so surrendered.

        10.     REPLACEMENT OF WARRANTS. Upon receipt of evidence reasonably
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant and (in the case of loss, theft or destruction) upon delivery of an
indemnity agreement (with surety if reasonably required) in an amount reasonably
satisfactory to the Company, or (in the case of mutilation) upon surrender and
cancellation of this Warrant, the Company will issue, in lieu thereof, a new
Warrant of like tenor.

        11.     TRANSFERS, ETC.

                (a) The Company will maintain a register containing the names
and addresses of the Registered Holders of this Warrant. Any Registered Holder
may change his, her or its address as shown on the warrant register by written
notice to the Company requesting such change.

                (b) Subject to the provisions of Section 4 hereof, this Warrant
and all rights hereunder are transferable, in whole or in part, upon surrender
of this Warrant with a properly executed assignment (in the form of EXHIBIT II
hereto) at the principal office of the Company.

                (c) Until any transfer of this Warrant is made in the warrant
register, the Company may treat the Registered Holder of this Warrant as the
absolute owner hereof for all purposes; PROVIDED, HOWEVER, that if and when this
Warrant is properly assigned in blank, the Company may (but shall not be
obligated to) treat the bearer hereof as the absolute owner hereof for all
purposes, notwithstanding any notice to the contrary.


                                     -6-

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        12.     MAILING OF NOTICES, ETC. All notices and other communications
from the Company to the Registered Holder of this Warrant shall be mailed by
first-class certified or registered mail, postage prepaid, to the address
furnished to the Company in writing by the last Registered Holder of this
Warrant who shall have furnished an address to the Company in writing. All
notices and other communications from the Registered Holder of this Warrant or
in connection herewith to the Company shall be mailed by first-class certified
or registered mail, postage prepaid, to the Company at its principal office set
forth below. If the Company should at any time change the location of its
principal office to a place other than as set forth below, it shall give prompt
written notice to the Registered Holder of this Warrant and thereafter all
references in this Warrant to the location of its principal office at the
particular time shall be as so specified in such notice.

        13.     NO RIGHTS AS STOCKHOLDER. Until the exercise of this Warrant,
the Registered Holder of this Warrant shall not have or exercise any rights by
virtue hereof as a stockholder of the Company.

        14.     CHANGE OR WAIVER. Any term of this Warrant may be changed or
waived only by an instrument in writing signed by the party against which
enforcement of the change or waiver is sought.

        15.     HEADINGS. The headings in this Warrant are for purposes of
reference only and shall not limit or otherwise affect the meaning of any
provision of this Warrant.

        16.     GOVERNING LAW. This Warrant will be governed by and construed in
accordance with the laws of the State of Texas.

                                       FIRST SEISMIC CORPORATION



                                       By:
                                          --------------------------------
[Corporate Seal]                       Title:
ATTEST:                                      -----------------------------

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


                                     -7-

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                                                                     EXHIBIT I

                                  PURCHASE FORM


To:     FIRST SEISMIC CORPORATION                       Dated:
                                                              ----------------


        The undersigned, pursuant to the provisions set forth in the attached
Warrant (No. __), hereby irrevocably elects to purchase ______ shares of the
Common Stock covered by such Warrant. The undersigned herewith makes payment of
$_____________________, representing the full purchase price for such shares at
the price per share provided for in such Warrant.


                                                 Signature:
                                                           -------------------
                                                 Address:
                                                         ---------------------

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

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                                                                      EXHIBIT II


                                ASSIGNMENT FORM


          FOR VALUE RECEIVED, __________________________________
hereby sells, assigns and transfers all of the rights of the undersigned under
the attached Warrant (No. ____) with respect to the number of shares of Common
Stock covered thereby set forth below, unto:


NAME OF ASSIGNEE                ADDRESS                   NO. OF SHARES
----------------                -------                   -------------


Dated:                                 Signature:
      ---------------------------                -----------------------------

Dated:                                 Witness:
      ---------------------------              -------------------------------