Exhibit 10.5

JOINDER AND AMENDMENT NO. 1
TO
REVOLVING CREDIT, TERM LOAN AND SECURITY AGREEMENT

THIS JOINDER AND AMENDMENT NO. 1 (this “Amendment”) is entered into as of
September 8, 2006, by and among GEOKINETICS INC., a Delaware corporation
(“Geokinetics”), GEOPHYSICAL DEVELOPMENT CORPORATION, a Texas corporation
(“GDC”), QUANTUM GEOPHYSICAL, INC., a Texas corporation (“Quantum”), TRACE
ENERGY SERVICES LTD., an entity organized under the laws of Canada (“Trace
Energy (Canada)”), and TRACE ENERGY SERVICES, INC., a Texas corporation (“Trace
Energy (U.S.)”) (Geokinetics, GDC, Quantum, Trace Energy (Canada) and Trace
Energy (U.S.), each an “Existing Borrower,” and collectively, the “Existing
Borrowers”), GEOKINETICS HOLDINGS, INC., a Delaware corporation (“Geokinetics
Holdings”), GRANT GEOPHYSICAL, INC., a Delaware corporation (“Grant
Geophysical”), GRANT GEOPHYSICAL (INT’L), INC., a Texas corporation (“Grant
Geophysical International”), GRANT GEOPHYSCAL CORP., a Texas corporation (“Grant
Corp”), GRANT SERVICES, INC., a Texas corporation (“Grant Services”), ADVANCED
SEISMIC TECHNOLOGY, INC. (“Advanced Seismic” and together with Geokinetics
Holdings, Grant Geophysical, Grant Geophysical International, Grant Corp and
Grant Services, each a “New Borrower” and collectively, the “New Borrowers”), 
PNC BANK, NATIONAL ASSOCIATION (“PNC”), the various financial institutions named
therein or which hereafter become a party thereto, (together with PNC,
collectively, “Lenders”) and PNC, as agent for the Lenders (in such capacity,
“Agent”).  The New Borrowers and the Existing Borrowers, individually a
“Borrower” and collectively, the “Borrowers”.

BACKGROUND

WHEREAS, Existing Borrowers, Agent and Lenders are parties to a Revolving
Credit, Term Loan and Security Agreement dated as of June 12, 2006 (as amended,
restated, supplemented or otherwise modified from time to time, the “Loan
Agreement”) pursuant to which Agent and Lenders provide Borrowers with certain
financial accommodations.

WHEREAS, in connection with the foregoing, Existing Borrowers have requested
that Agent and Lenders amend certain provisions of the Loan Agreement as
hereafter provided, and Agent and Lenders are willing to do so on the terms and
conditions hereafter set forth.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, the parties hereto hereby agree as follows:

1.             DEFINITIONS.  ALL CAPITALIZED TERMS NOT OTHERWISE DEFINED HEREIN
SHALL HAVE THE MEANINGS GIVEN TO THEM IN THE LOAN AGREEMENT.

2.             AMENDMENTS TO LOAN AGREEMENT.

(A)         THE DEFINITION OF “PURCHASING LENDER” SET FORTH IN SECTION 1.2 OF
THE LOAN AGREEMENT IS HEREBY AMENDED BY DELETING THE TEXT “SECTION 16.3”
CONTAINED THEREIN AND INSERTING THE TEXT “SECTION 16.3(C)” IN LIEU THEREOF.

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(B)         THE DEFINITION OF “TRANSFEREE” SET FORTH IN SECTION 1.2 OF THE LOAN
AGREEMENT IS HEREBY AMENDED BY DELETING THE TEXT “SECTION 16.3(C)” CONTAINED
THEREIN AND INSERTING THE TEXT “SECTION 16.3(D)” IN LIEU THEREOF.

(C)         SECTION 1.2 OF THE LOAN AGREEMENT IS HEREBY FURTHER AMENDED BY
INSERTING THE FOLLOWING DEFINED TERMS IN APPROPRIATE ALPHABETICAL ORDER:

“Advanced Seismic” shall mean Advanced Seismic Technology, Inc., a Texas
corporation.

“Asset Sale” shall mean the sale, transfer or other disposition (by way of
merger, casualty, condemnation or otherwise) by Geokinetics or any of the
Subsidiaries to any person other than Geokinetics or any Subsidiary of (a) any
Equity Interests of any of the Subsidiaries or (b) any other assets of
Geokinetics or any of its Subsidiaries.

“Consolidated EBITDA” shall mean, for any period, Consolidated Net Income for
such period plus

(a)           without duplication and to the extent deducted in determining such
Consolidated Net Income, the sum of

(i)            consolidated interest expense for such period,

(ii)           consolidated income tax expense for such period,

(iii)          foreign currency translation gain or loss,

(iv)          all amounts attributable to depreciation and amortization for such
period,

(v)           non-recurring fees and expenses incurred in connection with the
Transactions,

(vi)          any non-cash charges (other than the write-down of current assets)
for such period,

minus (b) without duplication all cash payments made during such period on
account of non-cash charges added to Consolidated Net Income pursuant to clause
(a)(vi) above in a previous period.

Consolidated EBITDA shall be calculated on a Pro Forma Basis to give effect to
the Grant Acquisition, and Asset Sales (other than any dispositions in the
ordinary course of business) consummated at any time on or after the first day
of the respective Test Period as if the Grant Acquisition had been effected on
the first day of such period and as if each such Asset Sale had been consummated
on the day prior to the first day of such period.

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“Consolidated Net Income” shall mean, for any period with respect to any person,
the net income or loss of such person for such period determined on a
consolidated basis in accordance with GAAP; provided, that there shall be
excluded (without duplication):

(a)           the income of any Subsidiary to the extent that the declaration or
payment of dividends or similar distributions by such Subsidiary of that income
is not at the time permitted by operation of the terms of its charter or any
agreement, instrument, judgment, decree, statute, rule or governmental
regulation applicable to such Subsidiary,

(b)           the income or loss of any person accrued prior to the date (i) it
becomes a Subsidiary or is merged into or consolidated with such person or (ii)
its assets are acquired by such person or its Subsidiaries,

(c)           the income or loss in respect of any Investment in a joint venture
(other than a Subsidiary) except to the extent of the amount of dividends or
other distributions actually paid to such person during such period,

(d)           after-tax gains and losses realized upon the sale or other
disposition of any property that is sold or otherwise disposed of other than in
the ordinary course of business, and

(e)           extraordinary gains, losses or charges.

“Debt for Borrowed Money” of any Person means, at any date of determination, the
sum of, without duplication, (a) all items that, in accordance with GAAP, would
be classified as indebtedness on a consolidated balance sheet of such Person at
such date and (b) all Capital Lease Obligations and Synthetic Lease Obligations
of such person and all obligations of such person as an account party in respect
of letters of credit or letters of guaranty, in each case, to the extent
functioning as indebtedness for borrowed money.

“Geokinetics Holdings” shall mean Geokinetics Holdings, Inc., a Delaware
corporation, a wholly owned subsidiary of Geokinetics.

“Grant Acquisition” shall mean the acquisition of all of the outstanding capital
stock of Grant Geophysical, Inc., a Delaware corporation, and its subsidiaries
pursuant to the Grant Acquisition Agreement.

“Grant Acquisition Agreement” shall mean that certain Stock Purchase Agreement
including all exhibits and schedules thereto dated as of September 8, 2006 by
and among Geokinetics Holdings, as buyer, and Elliot Associates, L.P., a
Delaware limited partnership and Elliot International, L.P., a Cayman Islands
limited partnership, as sellers.

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“Grant Corp” shall mean Grant Geophysical Corp., a Texas corporation.

“Grant Entities” shall mean individually and collectively, Grant Geophysical,
Grant Geophysical International, Grant Corp, Grant Services and Advanced
Seismic.

“Grant Geophysical” shall mean Grant Geophysical, Inc., a Delaware corporation.

“Grant Geophysical International” shall mean Grant Geophysical (Int’l), Inc., a
Texas corporation.

“Grant Services” shall mean Grant Services, Inc., a Texas corporation.

“Leverage Ratio” means, at any date of determination, the ratio of (a) Debt for
Borrowed Money (but excluding Subordinated Debt) as of the last day of such Test
Period to (b) Consolidated EBITDA for such Test Period, in each case as
determined for the Parent and its Subsidiaries on a consolidated basis.

“Modified Commitment Transfer Supplement” shall have the meaning set forth in
Section 16.3(d).

“Net Worth” shall mean, at a particular date, (a) the aggregate amount of all
assets of Geokinetics and its consolidated Subsidiaries as may be properly
classified as such in accordance with GAAP consistently applied, less (b) the
aggregate amount of all liabilities of Geokinetics and its consolidated
Subsidiaries.

“Purchasing CLO” shall have the meaning set forth in Section 16.3(d) hereof.

“Register” shall have the meaning set forth in Section 16.3(e).

“Senior Bridge Debt” shall mean the loans in the original principal amount of
$100,000,000 made by Royal Bank of Canada, as agent, and certain other lenders
to Geokinetics Holdings pursuant to that certain Credit Agreement dated as of
September 8, 2006.

“Senior Subordination Agreement” shall mean those certain subordination
provisions contained in the document evidencing the Subordinated Debt.

“Subordinated Debt” shall mean the loans in the original principal amount of
$55,000,000 made by lenders party thereto to Geokinetics pursuant to that
certain Senior Subordinated Loan Agreement dated as of September 8, 2006.

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“Synthetic Lease Obligations” shall mean all monetary obligations of a person
under (a) a so-called synthetic, off-balance sheet or tax retention lease or
(b) an agreement for the use or possession of any property (whether real,
personal or mixed) creating obligations which do not appear on the balance sheet
of such person, but which, upon the insolvency or bankruptcy of such person,
would be characterized as Indebtedness of such person (without regard to
accounting treatment).

(D)         SECTION 1.2 OF THE LOAN AGREEMENT IS HEREBY FURTHER AMENDED BY
AMENDING AND RESTATING THE FOLLOWING DEFINITIONS TO READ AS FOLLOWS:

“Acquisition Agreement” shall mean collectively, (a) the Stock Purchase
Agreement including all exhibits and schedules thereto dated as of July 29, 2005
between SCF-III, L.P., a Delaware limited partnership and James White, and
individual resident of Texas, as sellers  (individually and collectively,
“Seller”) and Geokinetics as buyer and (b) the Grant Acquisition Agreement.

“Capital Expenditures” shall mean, for any period, (a) the aggregate amount of
additions to property, plant and equipment and other capital expenditures of
Geokinetics and its Subsidiaries that are (or should be) set forth in a
consolidated statement of cash flows of Geokinetics for such period prepared in
accordance with GAAP, and (b) Capitalized Lease Obligations or Synthetic Lease
Obligations incurred by Geokinetics and its consolidated Subsidiaries during
such period, but excluding in each case any such expenditure made to restore,
replace or rebuild property to the condition of such property immediately prior
to any damage, loss, destruction or condemnation of such property, to the extent
such expenditure is made with insurance proceeds, condemnation awards or damage
recovery proceeds relating to any such damage, loss, destruction or
condemnation.

“Capitalized Lease Obligations” of any person shall mean the obligations of such
person to pay rent or other amounts under any lease of (or other arrangement
conveying the right to use) real or personal property, or a combination thereof,
which obligations are required to be classified and accounted for as capital
leases on a balance sheet of such person under GAAP, and the amount of such
obligations shall be the capitalized amount thereof determined in accordance
with GAAP.

“Collateral” shall mean and include:

(a)           all Receivables;

(b)           all Equipment;

(c)           all General Intangibles;

(d)           all Inventory;

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(e)           all Investment Property;

(f)            all Subsidiary Stock;

(g)           all of each Borrower’s right, title and interest in and to,
whether now owned or hereafter acquired and wherever located, (i) its respective
goods and other property including, but not limited to, all merchandise returned
or rejected by Customers, relating to or securing any of the Receivables;
(ii) all of each Borrower’s rights as a consignor, a consignee, an unpaid
vendor, mechanic, artisan, or other lienor, including stoppage in transit,
setoff, detinue, replevin, reclamation and repurchase; (iii) all additional
amounts due to any Borrower from any Customer relating to the Receivables;
(iv) other property, including warranty claims, relating to any goods securing
the Obligations; (v) all of each Borrower’s contract rights, rights of payment
which have been earned under a contract right, instruments (including promissory
notes), documents, chattel paper (including electronic chattel paper), warehouse
receipts, deposit accounts, letters of credit and money; (vi) all commercial
tort claims (whether now existing or hereafter arising); (vii) if and when
obtained by any Borrower, all real and personal property of third parties in
which such Borrower has been granted a lien or security interest as security for
the payment or enforcement of Receivables; (viii) all letter of credit rights
(whether or not the respective letter of credit is evidenced by a writing);
(ix) all supporting obligations; (x)  all licenses and permits to the extent
Borrowers may grant a security interest in the same in accordance with
Applicable Laws and (xi) any other goods, personal property or real property now
owned or hereafter acquired in which any Borrower has expressly granted a
security interest or may in the future grant a security interest to Agent
hereunder, or in any amendment or supplement hereto or thereto, or under any
other agreement between Agent and any Borrower;

(h)           all of each Borrower’s ledger sheets, ledger cards, files,
correspondence, records, books of account, business papers, computers, computer
software (owned by any Borrower or in which it has an interest), computer
programs, tapes, disks and documents relating to (a), (b), (c), (d), (e), (f),
or (g) of this Paragraph; and

(i)            all proceeds and products of (a), (b), (c), (d), (e), (f), (g),
or (h) in whatever form, including, but not limited to:  cash, deposit accounts
(whether or not comprised solely of proceeds), certificates of deposit,
insurance proceeds (including hazard, flood and credit insurance), negotiable
instruments and other instruments for the payment of money, chattel paper,
security agreements, documents, eminent domain proceeds, condemnation proceeds
and tort claim proceeds.

Notwithstanding the foregoing, with respect to each Grant Entity, the term
“Collateral” shall mean, whether now owned or hereafter acquired, (i) all

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Receivables of such Grant Entity, (ii) all Subsidiary Stock, (iii) all
additional amounts due to such Grant Entity from any Customer relating to the
Receivables of such Grant Entity, (iv) all of such Grant Entity’s ledger sheets,
ledger cards, files, correspondence, records, books of account, business papers,
computers, computer software (owned by such Grant Entity or in which it has an
interest), computer programs, tapes, disks and documents relating to (i), (ii),
or (iii) of this Paragraph and (iv) all proceeds and products of (i), (ii),
(iii) or (iv) of this Paragraph in whatever form, including, but not limited
to:  cash, deposit accounts (whether or not comprised solely of proceeds),
certificates of deposit, insurance proceeds (including hazard, flood and credit
insurance), negotiable instruments and other instruments for the payment of
money, chattel paper, security agreements, documents, eminent domain proceeds,
condemnation proceeds and tort claim proceeds.”

“Collateral Assignment of Acquisition Agreement” shall mean collectively, (a)
that certain Collateral Assignment of Acquisition Agreement dated as of the
Closing Date, executed by Geokinetics in favor of Agent and acknowledged by
Seller and (b) that certain Collateral Assignment of Acquisition Agreement dated
as of September 8, 2006, executed by Geokinetics Holdings in favor of Agent and
acknowledged by the sellers under the Grant Acquisition Agreement.

“Commitment Percentage” of any Lender shall mean the percentage set forth below
such Lender’s name on the signature page hereof as same may be adjusted upon any
assignment by a Lender pursuant to Section 16.3(c) or (d) hereof.

“Other Documents” shall mean the Note, the Negative Pledge, the Questionnaire,
the Pledge Agreement, the Collateral Assignment of Acquisition Agreement, the
Senior Subordination Agreement, the Guaranty, the Guarantor Security Agreement,
the Intellectual Property Security Agreement, any Lender-Provided Interest Rate
Hedge and any and all other agreements, instruments and documents, including
guaranties, pledges, powers of attorney, consents, interest or currency swap
agreements or other similar agreements and all other writings heretofore, now or
hereafter executed by any Borrower or any Guarantor and/or delivered to Agent or
any Lender in respect of the transactions contemplated by this Agreement.

“Test Period” shall mean, at any time, the four consecutive fiscal quarters of
Geokinetics most recently ended (in each case taken as one accounting period)
for which financial statements have been or are required to be delivered
pursuant to Section 9.7 or Section 9.8.

(E)         SECTION 2.21(A) OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED
TO READ AS FOLLOWS:

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“(a)         Subject to Section 4.3 hereof and excluding the exceptions set
forth therein, when Borrower (i) sells or otherwise disposes of any Collateral
other than Inventory in the Ordinary Course of Business, (ii) other than
conversion of the Subordinated Debt to Equity Interests, issues or sells any
equity securities, capital stock or other ownership interests, or receives any
capital contributions, (iii) incurs any Indebtedness (other than as permitted by
Section 7.8 hereof), or (iv) receives any proceeds payable in connection with
(A) any condemnation proceedings affecting any of the foregoing or any rights
thereto or any interest in or to any Collateral or (B) any damage to or taking
of any of the foregoing or any rights in any Collateral or any interest therein
arising from or otherwise relating to any exercise of the power of eminent
domain, or any conveyance in lieu of or under threat of any such taking, then
Borrower shall repay the Advances in an amount equal to the net cash proceeds of
the foregoing (i.e., gross proceeds less the reasonable costs of such sales,
issuances, contributions or other dispositions), such repayments to be made
promptly but in no event more than one (1) Business Day following receipt of
such net proceeds, and until the date of payment, such proceeds shall be held in
trust for Agent.  The foregoing shall not be deemed to be implied consent to any
such sale or transaction otherwise prohibited by the terms and conditions
hereof.  Such repayments shall be applied (x) first, to the outstanding
principal installments of the Term Loan in the inverse order of the maturities
thereof and (y) second, to the remaining Advances in such order as Agent may
determine, subject to Borrower’s ability to reborrow Revolving Advances in
accordance with the terms hereof.”

(F)          SECTION 5.21 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED
TO READ AS FOLLOWS:

“5.21       Business and Property of Borrowers.  Upon and after the Closing
Date, Borrowers do not propose to engage in any business other than the
acquisition and processing of high resolution seismic data for the petroleum
industry and activities necessary to conduct the foregoing.  On the Closing
Date, each Borrower will own all the property and possess all of the rights and
Consents necessary for the conduct of the business of such Borrower.”

(G)         SECTION 6.5 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“6.5         Financial Covenants.

(a)           Net Worth.  Maintain at all times a Net Worth in an amount not
less than $30,000,000.

(b)           Fixed Charge Coverage Ratio.  Cause to be maintained as of the end
of each Test Period, a Fixed Charge Coverage Ratio of not less than 1.10 to 1.0.

(c)           Leverage Ratio.  Maintain as at the last day of each Test

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Period a Leverage Ratio of not more than 3.25:1.00.”

(H)         SECTION 7.1 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“7.1         Merger, Consolidation, Acquisition and Sale of Assets.

(a)           Except for the Grant Acquisition, enter into any merger,
consolidation or other reorganization with or into any other Person or acquire
all or a substantial portion of the assets or Equity Interests of any Person or
permit any other Person to consolidate with or merge with it.

(b)           Sell, lease, transfer or otherwise dispose of any of its
properties or assets, except (i) dispositions of Inventory and Equipment to the
extent expressly permitted by Section 4.3 and (ii) any other sales or
dispositions expressly permitted by this Agreement.”

(I)          SECTION 7.3 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“7.3         Guarantees.  Become liable upon the obligations or liabilities of
any Person by assumption, endorsement or guaranty thereof or otherwise (other
than to Lenders) except (a) as disclosed on Schedule 7.3, (b) for any guaranty
of the Senior Bridge Debt, and (c) the endorsement of checks in the Ordinary
Course of Business.”

(J)          SECTION 7.4 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“7.4         Investments.  Except for the Grant Acquisition, purchase or acquire
obligations or Equity Interests of, or any other interest in, any Person, except
(a) obligations issued or guaranteed by the United States of America or any
agency thereof, (b) commercial paper with maturities of not more than 270 days
and a published rating of not less than A-1 or P-1 (or the equivalent rating),
(c) certificates of time deposit and bankers’ acceptances having maturities of
not more than 180 days and repurchase agreements backed by United States
government securities of a commercial bank if (i) such bank has a combined
capital and surplus of at least $500,000,000, or (ii) its debt obligations, or
those of a holding company of which it is a Subsidiary, are rated not less than
A (or the equivalent rating) by a nationally recognized investment rating
agency, and (d) U.S. money market funds that invest solely in obligations issued
or guaranteed by the United States of America or an agency thereof.”

(K)         SECTION 7.6 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“7.6         Capital Expenditures.   Permit the aggregate amount of Capital
Expenditures made by Geokinetics and its Subsidiaries in any fiscal year set
forth

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below to exceed the amount set forth below for such fiscal year:

Fiscal Year

 

Amount

 

2006

 

$

25,000,000

 

2007

 

$

25,000,000

 

 

(L)          SECTION 7.8 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“7.8         Indebtedness.  Create, incur, assume or suffer to exist any
Indebtedness (exclusive of trade debt) except in respect of (i) Indebtedness to
Lenders; (ii) Indebtedness incurred for the Permitted Capital Lease Facility and
Capital Expenditures permitted under Section 7.6 hereof; (iii) Indebtedness
listed on Schedule 7.8 hereto; and (iv) the Senior Bridge Debt and the
Subordinated Debt so long as such Subordinated Debt is subject to the Senior
Subordination Agreement.

(M)        SECTION 7.17 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“7.17       Prepayment of Indebtedness.  At any time, (i) other than the
conversion of the Subordinated Debt to Equity Interests, directly or indirectly,
prepay, repurchase, redeem, retire or otherwise acquire any subordinated
Indebtedness, (ii) use the proceeds of any Indebtedness to prepay, repurchase,
redeem, retire or otherwise acquire any other Indebtedness (including
subordinated Indebtedness), (iii) make or receive any payments whatsoever with
respect to any Intercompany Note without the prior written consent of Agent,
except, that, a Borrower may make or receive payments in satisfaction of such
Intercompany Note in the form of the Equity Interests of the debtor with respect
to such Intercompany Note and (iv) upon the occurrence and during the
continuation of a Default or Event of Default or if a Default or Event of
Default would result from such payment or transaction, or if Undrawn
Availability shall be less than $6,000,000 after giving effect to such
prepayment or transaction, prepay, repurchase, redeem, retire or otherwise
acquire any Indebtedness of any Borrower.”

(N)         SECTION 7.22 OF THE LOAN AGREEMENT IS HEREBY ADDED AFTER SECTION
7.21 TO READ AS FOLLOWS:

“7.22       Senior Bridge Debt and Subordinated Debt.  (a) Other than the
conversion of the Subordinated Debt to Equity Interests, make any payment or
distribution with respect to the Subordinated Debt except as expressly permitted
by the terms of the Senior Subordination Agreement, (b) permit any waiver,
supplement, modification, amendment, termination, release, refinancing or
refunding of any document evidencing the Senior Bridge Debt except to the extent
such waiver, supplement, modification, amendment, termination, release,

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refinancing or refunding do not materially affect the rights and privileges of
Geokinetics Holdings or any Subsidiary under such documents and that do not
materially affect the interests of the Agent or Lenders under the this Agreement
or the Other Documents, or (c) change or amend the terms of the Subordinated
Debt (or any indenture or agreement or other material document entered into in
connection therewith) if the effect of such amendment is to (i) increase the
interest rate on the Subordinated Debt, (ii) change the dates upon which
payments of principal or interest are due on the Subordinated Debt other than to
extend such dates, (iii) change any default or event of default other than to
delete or make less restrictive any default provision therein, or add any
covenant with respect to the Subordinated Debt, (iv) change the subordination
provisions of the Subordinated Debt, (v) change the redemption or prepayment
provisions of the Subordinated Debt other than to extend the dates therefor or
to reduce the premiums payable in connection therewith or (vi) change or amend
any other term if such change or amendment would materially increase the
obligations of the obligor or confer additional material rights to the holder of
the Subordinated Debt in a manner adverse to the Agent or Lenders.”

(O)         SECTION 13.1 OF THE LOAN AGREEMENT IS HEREBY AMENDED AND RESTATED TO
READ AS FOLLOWS:

“13.1       Term.  This Agreement, which shall inure to the benefit of and shall
be binding upon the respective successors and permitted assigns of each
Borrower, Agent and each Lender, shall become effective on the date hereof and
shall continue in full force and effect until the earlier of (i) September 8,
2007 (the “Term”), (ii) the date upon which any portion of the Senior Bridge
Debt is refinanced, or (iii) or upon any earlier date if terminated as herein
provided.  Borrowers may terminate this Agreement at any time upon ninety (90)
days’ prior written notice upon payment in full of the Obligations.  In the
event the Obligations are prepaid in full and all commitments to lend hereunder
are terminated prior to the last day of the Term (the date of such prepayment
hereinafter referred to as the “Early Termination Date”), Borrowers shall pay to
Agent for the benefit of Lenders an early termination fee in an amount equal to
(x) $180,000.00 if the Early Termination Date occurs on or after the Closing
Date to and including the date immediately preceding the first anniversary of
the Closing Date, or (y) $120,000.00 if the Early Termination Date occurs on or
after the first anniversary of the Closing Date.”

(P)         SECTION 16.3(C) OF THE LOAN AGREEMENT IS HEREBY AMENDED BY DELETING
THE TEXT “, AND TOGETHER WITH EACH PARTICIPANT, EACH A “TRANSFEREE” AND
COLLECTIVELY, THE “TRANSFEREES” APPEARING WITHIN THE PARENTHETICAL THEREIN.

(Q)         SECTION 16.3 IS HEREBY FURTHER AMENDED BY (I) RE-DESIGNATING
SUB-CLAUSES (D) AND (E) THEREOF, AS SUB-CLAUSE (E) AND (F), RESPECTIVELY, (II)
INSERTING THE FOLLOWING TEXT AS NEW SUB-CLAUSE (D):

“(d)         Any Lender, with the consent of Agent which shall not be

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unreasonably withheld or delayed, may directly or indirectly sell, assign or
transfer all or any portion of its rights and obligations under or relating to
Revolving Advances and/or Term Loans under this Agreement and the Other
Documents to an entity, whether a corporation, partnership, trust, limited
liability company or other entity that (i) is engaged in making, purchasing,
holding or otherwise investing in bank loans and similar extensions of credit in
the ordinary course of its business and (ii) is administered, serviced or
managed by the assigning Lender or an Affiliate of such Lender (a “Purchasing
CLO” and together with each Participant and Purchasing Lender, each a
“Transferee” and collectively the “Transferees”), pursuant to a Commitment
Transfer Supplement modified as appropriate to reflect the interest being
assigned (“Modified Commitment Transfer Supplement”), executed by any
intermediate purchaser, the Purchasing CLO, the transferor Lender, and Agent as
appropriate and delivered to Agent for recording.  Upon such execution and
delivery, from and after the transfer effective date determined pursuant to such
Modified Commitment Transfer Supplement, (i) Purchasing CLO thereunder shall be
a party hereto and, to the extent provided in such Modified Commitment Transfer
Supplement, have the rights and obligations of a Lender thereunder and (ii) the
transferor Lender thereunder shall, to the extent provided in such Modified
Commitment Transfer Supplement, be released from its obligations under this
Agreement, the Modified Commitment Transfer Supplement creating a novation for
that purpose.  Such Modified Commitment Transfer Supplement shall be deemed to
amend this Agreement to the extent, and only to the extent, necessary to reflect
the addition of such Purchasing CLO.  Each Borrower hereby consents to the
addition of such Purchasing CLO.  Borrowers shall execute and deliver such
further documents and do such further acts and things in order to effectuate the
foregoing.”

; and (iii) restating new sub-clause (e) to read in its entirety as set forth
below:

“(e)         Agent shall maintain at its address a copy of each Commitment
Transfer Supplement and Modified Commitment Transfer Supplement delivered to it
and a register (the “Register”) for the recordation of the names and addresses
of each Lender and the outstanding principal, accrued and unpaid interest and
other fees due hereunder.  The entries in the Register shall be conclusive, in
the absence of manifest error, and each Borrower, Agent and Lenders may treat
each Person whose name is recorded in the Register as the owner of the Advance
recorded therein for the purposes of this Agreement.  The Register shall be
available for inspection by Borrowers or any Lender at any reasonable time and
from time to time upon reasonable prior notice.  Agent shall receive a fee in
the amount of $3,500 payable by the applicable Purchasing Lender and/or
Purchasing CLO upon the effective date of each transfer or assignment (other
than to an intermediate purchaser) to such Purchasing Lender and/or Purchasing
CLO.”

3.             CONDITIONS OF EFFECTIVENESS OF AMENDMENT.  THE EFFECTIVENESS OF
THIS AMENDMENT IS SUBJECT TO THE SATISFACTION OF THE FOLLOWING CONDITIONS
PRECEDENT, UNLESS

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SPECIFICALLY WAIVED IN WRITING BY THE AGENT:

(A)         THE AGENT SHALL HAVE RECEIVED THE FOLLOWING DOCUMENTS OR ITEMS, EACH
IN FORM AND SUBSTANCE SATISFACTORY TO THE AGENT AND ITS LEGAL COUNSEL:

(1)           THIS AMENDMENT DULY EXECUTED BY EACH BORROWER;

(2)           THE CONSENT RATIFICATION AND RELEASE, AS ATTACHED TO THIS
AMENDMENT, DULY EXECUTED BY EACH GUARANTOR;

(3)           AN AMENDED AND RESTATED REVOLVING CREDIT NOTE, DULY EXECUTED BY
EACH BORROWER;

(4)           A PLEDGE AGREEMENT PLEDGING ALL STOCK OR EQUITY INTERESTS HELD BY
GEOKINETICS HOLDINGS, DULY EXECUTED BY GEOKINETICS HOLDINGS;

(5)           A PLEDGE AGREEMENT PLEDGING ALL STOCK OR EQUITY INTERESTS HELD BY
GRANT GEOPHYSICAL, DULY EXECUTED BY GRANT GEOPHYSICAL;

(6)           AN AMENDMENT TO THE PLEDGE AGREEMENT BETWEEN GEOKINETICS AND
AGENT, DULY EXECUTED BY GEOKINETICS;

(7)           A TRADEMARK SECURITY AGREEMENT DULY EXECUTED BY EACH OF THE GRANT
ENTITIES AND GEOKINETCS HOLDINGS;

(8)           A COLLATERAL ASSIGNMENT OF THE GRANT ACQUISITION AGREEMENT, DULY
EXECUTED BY THE SELLER THEREUNDER AND GEOKINETICS HOLDINGS;

(9)           A NEGATIVE PLEDGE AGREEMENT DULY EXECUTED BY EACH OF THE GRANT
ENTITIES AND GEOKINETCS HOLDINGS;

(10)         A FINANCIAL CONDITION CERTIFICATE DULY EXECUTED BY THE BORROWERS;

(11)         AN ACCOUNTANT’S LETTER DULY EXECUTED BY EACH OF THE GRANT ENTITIES
AND GEOKINETCS HOLDINGS;

(12)         A CLOSING CERTIFICATE DULY EXECUTED BY THE BORROWERS;

(13)         A SECRETARY’S CERTIFICATE OF EACH BORROWER, DULY EXECUTED BY EACH
BORROWER, TOGETHER WITH CERTIFIED ARTICLE OF INCORPORATION, BYLAWS, RESOLUTIONS,
INCUMBENCY AND GOOD STANDING CERTIFICATES FOR EACH BORROWER;

(14)         A LEGAL OPINION FROM BORROWERS’ COUNSEL COVERING SUCH MATTERS AS
DETERMINED BY AGENT;

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(15)         PAYOFF LETTERS DULY EXECUTED BY EACH CREDITOR OF GRANT GEOPHYSICAL
AND GRANT GEOPHYSICAL INTERNATIONAL INDICATING THAT ALL OBLIGATIONS HAVE BEEN
PAID IN FULL AND ALL LIENS AGAINST EACH ENTITY’S ASSETS HAVE BEEN RELEASED;

(16)         CERTIFIED COPIES OF EACH GRANT ENTITY’S CASUALTY INSURANCE
POLICIES, TOGETHER WITH LOSS PAYABLE ENDORSEMENTS ON AGENT’S STANDARD FORM OF
LOSS PAYEE ENDORSEMENT NAMING AGENT AS LOSS PAYEE, AND CERTIFIED COPIES OF EACH
GRANT ENTITY’S LIABILITY INSURANCE POLICIES, TOGETHER WITH ENDORSEMENTS NAMING
AGENT AS A CO-INSURED;

(17)         A TRANSACTION CERTIFICATE DULY EXECUTED BY BORROWERS, WHICH
INCLUDES COPIES OF ALL DOCUMENTS EXECUTED IN CONNECTION WITH THE GRANT
ACQUISITION (INCLUDING, WITHOUT LIMITATION, DOCUMENTS EVIDENCING THE SENIOR
BRIDGE DEBT AND SUBORDINATED DEBT);

(18)         POST-CLOSING AGREEMENT DULY EXECUTED BY THE BORROWERS;

(19)         PRO FORMA FINANCIAL STATEMENTS OF BORROWERS AS OF THE DATE HEREOF
AFTER GIVING EFFECT THE GRANT ACQUISITION; AND

(20)         ALL OTHER DOCUMENTS AGENT MAY REASONABLY REQUEST WITH RESPECT TO
ANY MATTER RELEVANT TO THIS AMENDMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY.

(B)         THE AGENT SHALL HAVE RECEIVED PAYMENT IN CASH OF AN AMENDMENT FEE
FROM BORROWERS IN THE AMOUNT OF $180,000 IN IMMEDIATELY AVAILABLE FUNDS.

(C)         THE AGENT SHALL HAVE RECEIVED PAYMENT OF ALL ACCRUED INTEREST ON,
FEES AND OUTSTANDING PRINCIPAL OF THE TERM LOAN IN IMMEDIATELY AVAILABLE FUNDS.

(D)         THE REPRESENTATIONS AND WARRANTIES CONTAINED HEREIN AND IN THE LOAN
AGREEMENT AND THE OTHER DOCUMENTS, AS EACH IS AMENDED HEREBY, SHALL BE TRUE AND
CORRECT IN ALL MATERIAL RESPECTS AS OF THE DATE HEREOF, AS IF MADE ON THE DATE
HEREOF;

(E)         THE GRANT ACQUISITION SHALL HAVE BEEN CONSUMMATED IN ACCORDANCE WITH
THE GRANT ACQUISITION AGREEMENT;

(F)          EACH DOCUMENT (INCLUDING ANY UNIFORM COMMERCIAL CODE FINANCING
STATEMENT) REQUIRED BY THE LOAN AGREEMENT, ANY RELATED AGREEMENT OR UNDER LAW OR
REASONABLY REQUESTED BY THE AGENT TO BE FILED, REGISTERED OR RECORDED IN ORDER
TO CREATE, IN FAVOR OF AGENT, A PERFECTED SECURITY INTEREST IN OR LIEN UPON THE
COLLATERAL SHALL HAVE BEEN PROPERLY FILED, REGISTERED OR RECORDED IN EACH
JURISDICTION IN WHICH THE FILING, REGISTRATION OR RECORDATION THEREOF IS SO
REQUIRED  OR REQUESTED, AND AGENT SHALL HAVE RECEIVED AN ACKNOWLEDGMENT COPY, OR
OTHER EVIDENCE SATISFACTORY TO IT, OF EACH SUCH FILING, REGISTRATION OR
RECORDATION AND SATISFACTORY EVIDENCE OF THE PAYMENT OF ANY NECESSARY FEE, TAX
OR EXPENSE RELATING THERETO;

(G)         NO DEFAULT OR EVENT OF DEFAULT SHALL HAVE OCCURRED AND BE
CONTINUING; AND

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(H)         ALL CORPORATE PROCEEDINGS TAKEN IN CONNECTION WITH THE TRANSACTIONS
CONTEMPLATED BY THIS AMENDMENT AND ALL DOCUMENTS, INSTRUMENTS AND OTHER LEGAL
MATTERS INCIDENT THERETO SHALL BE SATISFACTORY TO THE AGENT AND ITS LEGAL
COUNSEL.

4.             JOINDER AND ASSUMPTION.  EACH NEW BORROWER HEREBY JOINS IN,
ASSUMES, ADOPTS AND BECOMES A CO-DEBTOR AND A CO-OBLIGOR WITH RESPECT TO ALL
OBLIGATIONS UNDER THE LOAN AGREEMENT AND ALL OF THE OTHER DOCUMENTS, AND EACH
NEW BORROWER HEREBY JOINS IN, ASSUMES, ADOPTS AND BECOMES A CO-DEBTOR AND A
CO-OBLIGOR WITH RESPECT TO ALL OBLIGATIONS UNDER THE LOAN AGREEMENT AND ALL OF
THE OTHER DOCUMENTS WITH RESPECT TO THE EXISTING BORROWERS.  WITHOUT LIMITING
THE FOREGOING, EACH NEW BORROWER HEREBY AGREES TO (I) ALL OF THE TERMS AND
CONDITIONS CONTAINED IN THE LOAN AGREEMENT AND THE OTHER DOCUMENTS WITH THE SAME
LEGAL EFFECT AS IF IT WAS AN ORIGINAL SIGNATORY THERETO, INCLUDING, WITHOUT
LIMITATION, THE GRANT TO AGENT, FOR THE BENEFIT OF ITSELF AND THE LENDERS, A
CONTINUING GENERAL LIEN UPON, AND SECURITY INTEREST IN, ALL OF THE COLLATERAL IN
WHICH SUCH NEW BORROWER HAS RIGHTS AS SECURITY FOR THE OBLIGATIONS, AND (II) BE,
TOGETHER WITH THE OTHER BORROWERS, JOINTLY AND SEVERALLY LIABLE FOR ALL PRESENT
AND FUTURE OBLIGATIONS.

5.             ASSETS OF GRANT ENTITIES.  THE PARTIES HERETO AGREE AND
ACKNOWLEDGE THAT THE ASSETS OF THE GRANT ENTITIES WILL NOT BE CONSIDERED
ELIGIBLE DOMESTIC RECEIVABLES UNTIL SUCH TIME AS AGENT HAS DEEMED SUCH ASSETS TO
BE ELIGIBLE IN ITS SOLE CREDIT JUDGMENT FOR PURPOSES OF BEING INCLUDED IN THE
BORROWING BASE AND THEN ONLY TO THE EXTENT SUCH ASSETS MEET THE OTHER
REQUIREMENTS SET FORTH IN THE LOAN AGREEMENT.

6.             REPRESENTATIONS AND WARRANTIES.  THE PARTIES HERETO REPRESENT AND
WARRANT THAT THIS AMENDMENT AND THE LOAN AGREEMENT, AS AMENDED HEREBY,
CONSTITUTE LEGAL, VALID AND BINDING OBLIGATIONS OF THE PARTIES HERETO AND ARE
ENFORCEABLE AGAINST SUCH PARTY IN ACCORDANCE WITH THEIR RESPECTIVE TERMS.

7.             EFFECT ON THE AGREEMENT.

(A)         UPON THE EFFECTIVENESS OF SECTION 2 HEREOF, EACH REFERENCE IN THE
LOAN AGREEMENT TO “THIS AGREEMENT,” “HEREUNDER,” “HEREOF,” “HEREIN” OR WORDS OF
LIKE IMPORT SHALL MEAN AND BE A REFERENCE TO THE LOAN AGREEMENT AS AMENDED
HEREBY.

(B)         EXCEPT AS SPECIFICALLY AMENDED HEREIN, THE LOAN AGREEMENT, AND ALL
OTHER DOCUMENTS, INSTRUMENTS AND AGREEMENTS EXECUTED AND/OR DELIVERED IN
CONNECTION THEREWITH, SHALL REMAIN IN FULL FORCE AND EFFECT, AND ARE HEREBY
RATIFIED AND CONFIRMED.

(C)         THE EXECUTION, DELIVERY AND EFFECTIVENESS OF THIS AMENDMENT SHALL
NOT OPERATE AS A WAIVER OF ANY RIGHT, POWER OR REMEDY OF AGENT OR LENDERS, NOR
CONSTITUTE A WAIVER OF ANY PROVISION OF THE LOAN AGREEMENT, OR ANY OTHER
DOCUMENTS, INSTRUMENTS OR AGREEMENTS EXECUTED AND/OR DELIVERED UNDER OR IN
CONNECTION THEREWITH.

8.             GOVERNING LAW.  THIS AMENDMENT SHALL BE BINDING UPON AND INURE TO
THE BENEFIT OF THE PARTIES HERETO AND THEIR RESPECTIVE SUCCESSORS AND ASSIGNS
AND SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE
OF TEXAS, WITHOUT REGARD TO ANY CONFLICTS OF LAWS PRINCIPLES THERETO THAT WOULD
CALL FOR THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION.

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9.             HEADINGS.  SECTION HEADINGS IN THIS AMENDMENT ARE INCLUDED HEREIN
FOR CONVENIENCE OF REFERENCE ONLY AND SHALL NOT CONSTITUTE A PART OF THIS
AMENDMENT FOR ANY OTHER PURPOSE.

10.           COUNTERPARTS; FACSIMILE.  THIS AMENDMENT MAY BE EXECUTED BY THE
PARTIES HERETO IN ONE OR MORE COUNTERPARTS, EACH OF WHICH SHALL BE DEEMED AN
ORIGINAL AND ALL OF WHICH WHEN TAKEN TOGETHER SHALL CONSTITUTE ONE AND THE SAME
AGREEMENT. ANY SIGNATURE DELIVERED BY A PARTY BY FACSIMILE TRANSMISSION SHALL BE
DEEMED TO BE AN ORIGINAL SIGNATURE HERETO.

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IN WITNESS WHEREOF, this Amendment has been duly executed as of the day and year
first written above.

PNC BANK, NATIONAL ASSOCIATION,

 

as Agent and Lender

 

 

 

By:

/s/ Douglas Motl

 

 

Name:

Douglas Motl

 

 

Title:

 

Vice President

 

 

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

 

ACKNOWLEDGED AND AGREED:

 

 

 

 

 

GEOKINETICS INC.,

 

as Borrowing Agent and as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

President

 

 

 

 

 

GEOPHYSICAL DEVELOPMENT CORPORATION,

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

QUANTUM GEOPHYSICAL, INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

TRACE ENERGY SERVICES LTD.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

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

 

TRACE ENERGY SERVICES, INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

GEOKINETICS HOLDINGS, INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

GRANT GEOPHYSICAL, INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

GRANT GEOPHYSICAL (INT’L), INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

GRANT GEOPHYSICAL CORP.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

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

 

GRANT SERVICES, INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

 

 

 

ADVANCED SEISMIC TECHNOLOGY, INC.,

 

as a Borrower

 

 

 

 

 

By:

/s/ David A. Johnson

 

Name:

David A. Johnson

 

Title:

 

Vice President

 

 

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