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                                                                   EXHIBIT 10.19

                        AMENDMENT TO DEPOSITORY AGREEMENT
                               FOR PURCHASE OPTION


     THIS FIRST AMENDMENT TO DEPOSITORY AGREEMENT FOR PURCHASE OPTION (this
"Amendment") is entered into as of January 25, 2001 by and between Grant
Geophysical Corp., a Texas corporation ("Grant"), and Elliott Associates, L.P.,
a Delaware limited partnership ("Elliott").

                                   WITNESSETH:

     WHEREAS, Grant and Elliott are the parties to that certain Depository
Agreement for Purchase Option dated as of December 1, 2000 (the "Depository
Agreement"); and

     WHEREAS, Grant and Elliott deem it in their best interests to amend the
Depository Agreement to extend the expiration date of the Option and
concurrently to increase the amount of the exercise price of the Option and the
Deposit.

     NOW, THEREFORE, the parties agree as follows:

     1. Section 1(a) of the Depository Agreement is amended to read in its
     entirety as follows:

        "(a) Purchase Option. Grant hereby grants to Elliott the exclusive
            option (the "Option") to purchase on or before March 31, 2001 all of
            Grant's right, title and interest, consisting of, among other
            things, a 33.333333% undivided working interest, in and to the
            mineral leases constituting the LaFite Project area in Brazoria
            County Texas, together with all of Grant's right, title and interest
            in and to any geophysical and geological data related thereto (the
            "Interest")."

     2. Section 1(b) of the Depository Agreement is amended to read in its
     entirety as follows:

        "(b) Purchase Price. The exercise price of the Option shall be the sum
            of $1,850,000, payable in the manner set forth in Section 1(c)."

     3. Section 1(c) of the Depository Agreement is amended in its entirety to
     read as follows:

        "(c) Refundable Deposit.

             (i) Concurrent with the execution hereof, Elliott shall place on
                 deposit with Grant a $1,850,000 refundable deposit (the
                 "Deposit").


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             (ii)   Elliott may exercise the Option without payment of further
                    consideration by giving Grant written notice of exercise
                    that includes the date on or before March 31, 2001 upon
                    which the purchase of the Interest shall close. On the
                    closing date (A) Grant shall deliver to Elliott an
                    assignment, bill of sale and conveyance in a form acceptable
                    to Elliott and such other documents as may be necessary to
                    convey title to the Interest and (B) upon such delivery the
                    Deposit shall become Grant's property.

             (iii)  Between the date hereof and March 31, 2001, if Grant elects
                    to sell the Interest to a third party before Elliott
                    exercises the Option, the Option shall be cancelled. In such
                    event, Grant shall give Elliott written notice of such
                    election and refund the Deposit, together with a termination
                    fee of $616.66 for each day beginning on the date hereof and
                    ending on the day the refund and termination fee are paid.

             (iv)   If (A) Elliott gives Grant written notice that it elects not
                    to exercise the Option, or (B) the Option is not exercised
                    on or before March 31, 2001, Grant shall refund the Deposit
                    to Elliott no later than two business days after the earlier
                    of receipt of such written notice from Elliott or March 31,
                    2001."

     4. Wherever and in each place the term "Agreement" is used throughout the
Depository Agreement, such term shall be read to mean the Depository Agreement,
as amended by this Amendment.

     5. Except as specifically amended by this Amendment, all of the terms and
provisions of the Depository Agreement shall remain in full force and effect.

     6. All capitalized terms used herein but not defined herein shall have the
meanings given to them in the Depository Agreement.

     7. This Amendment shall be governed by and construed in accordance with the
internal laws of the State of New York.

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     IN WITNESS WHEREOF, the parties hereto have executed this Amendment as of
the date first written above.

WITNESSES:                             GRANT GEOPHYSICAL CORP.

                                       By:
------------------------------             --------------------------------
                                       Name:
                                             ------------------------------
                                       Title:
------------------------------                -----------------------------

WITNESSES:                             ELLIOTT ASSOCIATES, L.P.

                                       By:
------------------------------             --------------------------------
                                       Name:
                                             ------------------------------
                                       Title:
------------------------------                -----------------------------

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