PLEDGE AGREEMENT



                  This Pledge Agreement is entered into as of November 17, 1997,
by and between:

PLEDGOR:          3-D GEOPHYSICAL, INC.
                  8226 Park Meadows Drive
                  Littleton, Colorado  80124

                                  AND

PLEDGEE:          SANWA BUSINESS CREDIT CORPORATION
                  550 North Brand Boulevard
                  Glendale, California 91203

         WHEREAS, 3-D Geophysical, Inc., a Delaware corporation ("Pledgor") owns
ninety-nine  percent (99%) of the issued and outstanding shares of capital stock
of (i) Geoevaluaciones,  S.A. de C.V., and (ii) Procesos Interactivos Avanzados,
S.A. de C.V. (collectively, the "Companies");

         WHEREAS,  Northern Geophysical of America, Inc., a Delaware corporation
("Borrower")   has   received  or  will  receive   loans  and  other   financial
accommodations made by Sanwa Business Credit Corporation ("Pledgee") pursuant to
a Loan and Security  Agreement dated as of the date hereof between  Borrower and
Pledgee (the "Loan Agreement");

         WHEREAS,  in consideration for such financial  accommodations,  Pledgor
has  guarantied  the  obligations  of Borrower to Pledgee  pursuant to a Secured
Continuing  Corporate  Guaranty  dated as of the date hereof  (the  "Guaranty"),
which Guaranty is secured by, among other things, this Pledge Agreement.

         NOW  THEREFORE,  for  value  received,  and  in  consideration  of  the
foregoing recitals, Pledgor and Pledgee hereby agree as follows:

         1. Pledge of Collateral and Delivery of Pledged Collateral.

                  1.1 Pledgor  hereby  pledges and assigns to Pledgee and grants
to Pledgee a security  interest in all of the Collateral  described in Section 2
below, whether now owned or hereafter acquired,  now or at any time hereafter in
the  possession,  custody or control of Pledgee or its agents,  whether held for
safekeeping, in a safe deposit box, or otherwise ("Collateral") to secure prompt
payment and full  performance  of the  obligations  described in Section 3 below
(collectively, "Obligations").

                  1.2 Pledgor  hereby  delivers to Pledgee all  certificates  or
instruments   representing  or  evidencing  the  Collateral  duly  endorsed  "en
garantia,"  together with a certified copy of the stock registry book of each of
the Companies evidencing the registration of this pledge therein.  Pledgee shall
have the right, at any time, after an Event of Default (as defined  herein),  in
its reasonable  discretion  and without notice to Pledgor,  to transfer to or to
register  in the  name  of  Pledgee  or any  of its  nominees  any or all of the
Collateral. In




addition,  Pledgee shall have the right at any time to exchange  certificates or
instruments   representing   or  evidencing   Collateral  for   certificates  or
instruments of smaller or larger denominations.

         2. Collateral. The Collateral consists of the following:

                  2.1 Sixty-five percent (65%) in the aggregate of the shares of
common stock of the Companies,  all such stock owned  beneficially and of record
by Pledgor and listed on Schedule I attached hereto and made a part hereof,  and
all cash, dividends, other securities, instruments, rights and other property at
any time and from time to time received or  receivable in respect  thereof or in
exchange  for all or any  part  thereof,  including  without  limitation,  stock
dividends,  warrants,  rights  to  subscribe,   conversion  rights,  liquidating
dividends and other stock rights,  and in the event Pledgor  receives any of the
foregoing,  Pledgor  acknowledges  that the same shall be  received IN TRUST for
Pledgee and agrees  immediately  to deliver the same to Pledgee in original form
of receipt, together with any stock or bond powers, assignments, endorsements or
other  documents or instruments as Pledgee may reasonably  request to establish,
protect or perfect Pledgee's interest in respect of such Collateral; and

                  2.2 Subject to the terms of Section  7.1.2  hereof,  all other
property  hereafter  delivered  to  Pledgee  (or any agent or bailee  holding on
behalf of Pledgee) by Pledgor in  substitution  for or in addition to any of the
foregoing,  all  certificates  and  instruments  representing or evidencing such
other property and all cash, dividends,  other securities,  instruments,  rights
and other  property at any time and from time to time  received or receivable in
respect  thereof or in exchange for all or any part thereof,  including  without
limitation, stock dividends,  warrants, rights to subscribe,  conversion rights,
liquidating  dividends and other stock rights, and in the event Pledgor receives
any of the foregoing,  Pledgor  acknowledges  that the same shall be received IN
TRUST for  Pledgee  and agrees  immediately  to  deliver  the same to Pledgee in
original form of receipt,  together with any stock or bond powers,  assignments,
endorsements  or other  documents  or  instruments  as  Pledgee  may  request to
establish,  protect or perfect Pledgee's interest in respect of such Collateral;
and

                  2.3 All proceeds of all of the foregoing.

         3. Obligations. The Obligations secured under this Pledge Agreement are
the  obligations of Pledgor under the Guaranty and under this Pledge  Agreement,
and  all  extensions,  amendments,  modifications  and  renewals  of  any of the
foregoing.

         4.  Representations and Warranties.  Pledgor represents and warrants on
the date  hereof,  and shall be deemed to  represent  and warrant on the date of
each loan or advance made by Pledgee to Borrower, that:

                  4.1 Pledgor is the sole legal,  beneficial and, if applicable,
record owner of the Collateral  (or, in the case of  after-acquired  Collateral,
will be the sole such owner thereof),  having good and marketable title thereto,
free of all liens, security interests, encumbrances or claims of any kind;


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                  4.2 All information  heretofore,  herein or hereafter given to
Pledgee by or on behalf of Pledgor is complete, true and correct.

                  4.3 All shares of stock constituting  Collateral (a) have been
duly and validly issued in compliance  with all  applicable  laws, (b) are fully
paid,  nonassessable  (liberadas)  and free of  preemptive  rights,  (c) are not
subject to any restrictions  upon the voting rights or upon the transfer thereof
other  than as may  appear  on the  face  of the  certificates  evidencing  such
Collateral,  and (d)  include  not less than 65% of the issued  and  outstanding
shares of each class of voting stock of each of the Companies;

                  4.4 Pledgor has the right and power and is duly authorized and
empowered to enter into, execute, deliver and perform this Pledge Agreement;

                  4.5 This Pledge Agreement has been duly executed and delivered
by Pledgor and  constitutes  a legal,  valid and binding  obligation of Pledgor,
enforceable against Pledgor in accordance with its terms;

                  4.6 Upon  delivery to Pledgee of the  certificates  evidencing
the  Collateral,  endorsed "en garantia" and the  registration of this pledge in
the registry books of the Companies,  the security  interest created herein will
constitute a valid, perfected first priority security interest in the Collateral
enforceable  in  accordance  with its terms against all creditors of Pledgor and
any person purporting to purchase any Collateral from Pledgor.

                  4.7 The  execution,  delivery and  performance  of this Pledge
Agreement do not (i) violate any  provisions of law or any order of any court or
other agency of  government,  or (ii)  contravene  any provision of any material
contract  or  agreement  to which  Pledgor  is a party or by  which  Pledgor  or
Pledgor's assets are bound; and

                  4.8 Each of the  representations  and  warranties set forth in
Paragraph 16 of the Guaranty is accurate and complete as of the date hereof.

         5.  Covenants  of  Pledgor.  Until  the  Obligations  are paid in full,
Pledgor agrees to:

                  5.1 Preserve and protect the  Collateral as a first  priority,
perfected security interest;

                  5.2 Not  create,  incur,  assume or permit to exist any liens,
encumbrances, security interests, levies, assessments or charges on or in any of
the Collateral, except those approved in advance in writing by Pledgee;

                  5.3  Promptly  pay  and  discharge   before  the  same  become
delinquent all taxes,  assessments and governmental charges or levies imposed on
Pledgor or any of the Collateral;

                  5.4 Not sell,  encumber,  or otherwise  dispose of or transfer
any  Collateral,  or any right or  interest  therein and agrees that it will (i)
cause the  Companies  not to issue any other  voting  stock in addition to or in
substitution  for the  Collateral,  except to  Pledgor,  or in  connection  with
outstanding  stock options or with the prior written consent of Pledgee and (ii)
pledge hereunder, immediately upon Pledgor's acquisition (directly or


                                      - 3 -




indirectly)  thereof, any and all additional shares of stock or other securities
of the Companies;

                  5.5 Appear in and defend, at Pledgor's own expense, any action
or proceeding which may affect  Pledgor's title to or Pledgee's  interest in the
Collateral;

                  5.6 Procure or execute and deliver, from time to time, in form
and  substance   satisfactory  to  Pledgee,   any  stock  powers,  bond  powers,
endorsements,  assignments, financing statements, estoppel certificates or other
writings  deemed  necessary or  appropriate  by Pledgee to perfect,  maintain or
protect Pledgee's  security interest in the Collateral and the priority thereof,
and take such other action and deliver  such other  documents,  instruments  and
agreements pertaining to the Collateral as Pledgee may request to effectuate the
intent of this Pledge Agreement;

                  5.7 If Pledgee gives value to enable Pledgor to acquire rights
in or use of any Collateral, use such value only for such purpose;

                  5.8  Keep  separate,  accurate  and  complete  records  of the
Collateral and provide  Pledgee with access  thereto and to Pledgor's  financial
records, in each case with the right to make extracts therefrom;

                  5.9 Provide  Pledgee  with copies of all reports  filed by the
Companies or Pledgor with the Securities and Exchange Commission within ten (10)
business days after the last date such report is required to be filed;

                  5.10 Provide Pledgee with such other information pertaining to
the Collateral as Pledgee may reasonably request from time to time;

                  5.11  Maintain  and  preserve  its  corporate  or other  legal
existence  and  that  of its  majority-owned  subsidiaries,  including,  without
limitation,  the  Companies,  and all rights,  privileges,  franchises and other
authority necessary for the conduct of their respective businesses; and

                  5.12 Continue its operations in the same form and structure of
business (i.e., corporate, partnership,  individual) as currently conducted, and
not  merge  or  consolidate  with  or  acquire  or  be  acquired  by  any  other
corporation,  partnership,  entity or person,  without  Pledgee's  prior written
consent; and

                  5.13 At all times comply with the covenants and agreements set
forth in the Guaranty.

         6. Authorized Action by Pledgee.

                  6.1  Pledgor  hereby  irrevocably   appoints  Pledgee  as  its
attorney-in-  fact to do (but  Pledgee  shall not be  obligated to and shall not
incur any  liability to Pledgor or any third party for failure so to do) any act
which Pledgor is obligated by this Pledge  Agreement to do, and to exercise such
rights and powers as Pledgor  might  exercise  with  respect to the  Collateral,
including, without limitation, the right to:


                                      - 4 -




                           6.1.1 collect by legal  proceedings  or otherwise and
endorse,  receive  and  receipt for all  payments,  proceeds  and other sums and
property  now or  hereafter  payable on or in respect of proceeds and other sums
and  property  now or  hereafter  payable on or in  respect  of the  Collateral,
including dividends and interest payments;

                           6.1.2  enter  into  any  extension,   reorganization,
deposit,  merger or consolidation agreement or other agreement pertaining to the
Collateral,  and in connection therewith may deposit or surrender control of the
Collateral  thereunder,  accept other property in exchange therefor,  and do and
perform  such acts and things as it may deem  proper,  and any money or property
secured in  exchange  therefor  shall be applied to the  Obligations  or held by
Pledgee pursuant to the provisions of this Pledge Agreement;

                           6.1.3 protect and preserve the Collateral;

                           6.1.4  transfer  the  Collateral  to  its  own or its
nominee's name; and

                           6.1.5 make any compromise,  settlement or adjustment,
and take any action it deems advisable, with respect to the Collateral;

provided,  however,  that  Pledgee  shall only  exercise  such rights  after the
occurrence  and  during the  continuation  of an Event of  Default  (as  defined
herein),  except that upon the cure of any Event of Default,  Pledgee shall have
the right to complete any action commenced by it during such Event of Default.

                  6.2 Pledgor  agrees to  reimburse  Pledgee upon demand for any
costs and expenses, including attorneys' fees, Pledgee may incur while acting as
Pledgor's  attorney-in-fact  hereunder,  all of which  costs  and  expenses  are
included in the  Obligations  secured hereby and are payable upon demand.  It is
further  agreed and  understood  between  the  parties  hereto that such care as
Pledgee  gives  to the  safekeeping  of its  own  property  of like  kind  shall
constitute  reasonable  care of the  Collateral  when in  Pledgee's  possession;
provided,  however,  that Pledgee shall not be required to make any presentment,
demand or  protest,  or give any notice and need not take any action to preserve
any rights  against any prior party or any other person in  connection  with the
Obligations or with respect to the Collateral.

                  6.3  If  Pledgor's  records  are  prepared  or  retained  by a
computer service company or any accountant or accounting service, so long as any
Obligations are outstanding, Pledgor grants Pledgee the absolute and irrevocable
right to inspect  such  records,  receive  duplicate  copies of all  information
furnished  to Pledgor and prepared by such  company,  accountant  or  accounting
service,  and agrees to furnish such  consents as may be necessary to effectuate
the same.  Pledgor  further  agrees to promptly  notify  Pledgee of the name and
address of such company,  accountant or accounting  service and of any change in
respect thereof.

                  6.4 All the foregoing powers authorized herein,  being coupled
with an interest, are irrevocable so long as any Obligations are outstanding.


                                      - 5 -




         7. Transfer, Voting, Dividends, Etc.

                  7.1  Notwithstanding any other provision hereof, so long as no
Event of Default (as defined herein) shall have occurred and be continuing:

                           7.1.1  Pledgor  shall be  entitled  to  exercise  all
voting  powers   pertaining  to  all  shares  of  stock  and  other   securities
constituting  Collateral for all purposes not inconsistent with the terms of the
Loan Agreement and this Pledge Agreement;

                           7.1.2 To the extent  permitted in the Loan Agreement,
Pledgor shall be entitled to receive and retain all dividends  (other than stock
or liquidating  dividends) and all interest  payments  payable in respect of the
Collateral;  provided, however, that all stock or property representing stock or
liquidating  dividends or a distribution or return of capital upon or in respect
of the shares of stock  constituting  Collateral  or resulting  from a split-up,
revision  or  reclassification  of  such  Collateral  or  received  in  exchange
therefor, as a result of a merger,  consolidation or otherwise, shall be paid or
transferred directly to Pledgee immediately upon receipt thereof by Pledgor, and
shall be retained by Pledgee as Collateral hereunder; and

                           7.1.3 in order to permit  Pledgor  to  exercise  such
voting powers and to receive such dividends  Pledgee shall,  if necessary,  upon
the written  request of the Pledgor,  from time to time,  execute and deliver to
Pledgor appropriate proxies.

                  7.2 If any Event of Default  (as  defined  herein)  shall have
occurred and while the same is continuing:

                           7.2.1 Pledgee, or its nominee or nominees,  shall, at
its option  (after  notice to  Pledgor  of  Pledgee's  intent to  exercise  such
rights),  have the sole  and  exclusive  right to  exercise  all  voting  powers
pertaining to the shares of stock  constituting  Collateral,  and shall exercise
such  powers in such  manner as Pledgee may elect,  and  Pledgor  hereby  grants
Pledgee an  irrevocable  proxy,  coupled with an interest to vote such shares of
stock;  provided,  however,  that such proxy shall terminate upon termination of
Pledgee's security interest therein; and

                           7.2.2 All dividends and other distributions made upon
or in  respect  of  shares of stock  constituting  Collateral  and all  interest
payments  shall  be paid  directly  to and  shall  be  retained  by  Pledgee  as
Collateral hereunder.

         8. Default and Remedies.

                  8.1  The  occurrence  of  any  of  the  following   events  or
conditions  (herein  "Events of  Default")  shall,  at the option of Pledgee and
without  notice  to or  demand  on  Pledgor,  constitute  an  Event  of  Default
hereunder:

                           8.1.1 any  Default,  under and as defined in the Loan
Agreement, shall have occurred and be continuing;

                           8.1.2  breach,  violation or  non-performance  of any
warranty, covenant or undertaking on Pledgor's part hereunder; or


                                      - 6 -




                           8.1.3  breach,  violation or  non-performance  of any
warranty,  covenant or undertaking  on Pledgor's part under any other  agreement
with Pledgee (including, without limitation, the Guaranty).

                  8.2 Upon the occurrence of any Event of Default,  Pledgee may,
at its option,  without notice to or demand on Pledgor,  declare all Obligations
immediately  due and payable,  and Pledgee shall have all the default rights and
remedies  of a secured  party under  Chapter 5 of  Division 9 of the  California
Uniform Commercial Code and other applicable law as well as the following rights
and remedies,  all of which may be exercised  with or without  further notice to
Pledgor, at Pledgee's sole option and as Pledgee in its sole discretion may deem
advisable:

                           8.2.1 to  settle,  compromise  or  release,  on terms
acceptable to Pledgee, in whole or in part, any amounts owing on the Collateral,
and to extend the time of payment,  in Pledgee's name or in the name of Pledgor,
in respect thereof;

                           8.2.2 to apply to the payment of the Obligations,  or
set-off or collect the Collateral, notwithstanding any forfeiture of interest or
loss of other rights of Pledgor against any obligor on the Collateral  resulting
from such action; and

                           8.2.3 to sell or otherwise dispose of the Collateral,
or any part thereof,  either at public or private sale, on any broker's board or
securities exchange, in lots or in bulk, for cash, on credit or otherwise,  with
or  without  representations  or  warranties,  and upon  such  terms as shall be
acceptable to Pledgee.

                  8.3 The net  cash  proceeds  resulting  from  the  collection,
liquidation,  sale,  or other  disposition  of the  Collateral  shall be applied
first,  to the expenses  (including  all attorneys'  fees) of holding,  storing,
preparing for sale, selling, collecting, liquidating and the like, including any
brokerage  commissions and stamp or transfer taxes, and then to the satisfaction
of all Obligations secured hereby,  application as to any particular  obligation
or  indebtedness  or against  principal or interest to be in Pledgee's  absolute
discretion.

                  8.4  If  by  reason  of  any  prohibition   contained  in  the
Securities  Act of  1933,  as now  or  hereafter  in  effect,  or in  applicable
California or other state securities laws, as now or hereafter in effect,  or in
any  rules or  regulations  pertaining  to any of the  foregoing  laws,  Pledgee
believes it is  compelled  to resort to one or more  private  sales of shares of
stock  constituting  Collateral to a single  purchaser or a restricted  group of
purchasers  who will be obliged to agree,  among other  things,  to acquire such
securities  for their own  account,  for  investment  and not with a view to the
distribution or resale  thereof,  Pledgor  acknowledges  and agrees that private
sales of such Collateral may be held  notwithstanding  that such sales may be at
prices and on other terms less favorable to Pledgor than if such Collateral were
sold at public sale.  Pledgor  further  agrees that Pledgee has no obligation to
delay the sale of any such Collateral for the period of time necessary to permit
registration  of the  Collateral,  even if the issuer thereof would,  or should,
agree to register such  Collateral for public sale under  applicable  securities
laws.  Pledgor  specifically  agrees that private sales made under the foregoing
circumstances  shall be deemed to have been made in a "commercially  reasonable"
manner.


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                  8.5 Pledgor further  acknowledges  and recognizes that Pledgee
may be unable to effect a public sale of all or a part of the Collateral and may
be  compelled  to  resort  to one or more  private  sales  of  shares  of  stock
constituting  Collateral  to  a  single  purchaser  or  a  restricted  group  of
purchasers  who will be obligated to agree,  among other things,  to acquire the
Collateral  for their own  account,  for  investment  and not with a view to the
distribution or resale thereof. Pledgor acknowledges that any such private sales
may be at prices and on terms  less  favorable  to Pledgee  than those of public
sales, and agrees that such private sales shall be deemed to have been made in a
commercially  reasonable  manner and that Pledgee has no obligation to delay the
sale of any  Collateral  to permit the issuer  thereof to register it for public
sale under the Securities Act.

         9. Duty of Pledgee.  Pledgee  shall not be under any duty or obligation
whatsoever to collect any dividends,  interest or other payments due or accruing
in  respect  of the  Collateral  or to take any  action  to  preserve  rights in
connection with any Collateral,  including, without limitation, making or giving
any presentment, demands for performance, notices of non-performance,  protests,
notices of protest or notices of dishonor in connection with any Collateral.

         10. Cumulative Rights. The rights, powers and remedies of Pledgee under
this Pledge  Agreement  shall be in addition to all rights,  powers and remedies
given to Pledgee under any statute or rule of law, this Pledge  Agreement or any
other  agreement,  all of which rights,  powers and remedies shall be cumulative
and may be exercised successively or concurrently.

         11. Waiver. Any forbearance,  failure or delay by Pledgee in exercising
any right, power or remedy shall not preclude the further exercise thereof,  and
every right,  power or remedy of Pledgee shall continue in full force and effect
until such right,  power or remedy is specifically  waived in a writing executed
by Pledgee.  Pledgor waives any right to require  Pledgee to proceed against any
person or to exhaust any  Collateral or to pursue any remedy in Pledgee's  power
prior to pursuing Pledgor in respect of the Obligations.

         12.  Setoff.  Pledgor  agrees that  Pledgee may  exercise its rights of
setoff with respect to the  Obligations in the same manner as if the Obligations
were unsecured.

         13.  Binding Upon  Successors.  All rights of Pledgee under this Pledge
Agreement  shall inure to the benefit of its  successors  and  assigns,  and all
obligations  of  Pledgor  shall bind the  representatives,  and  successors  and
assigns of the Pledgor.

         14. Waiver of Suretyship Defenses. Pledgor hereby reaffirms each of the
waivers given in the Guaranty as if each such waiver was fully set forth herein.

         15.  Substituted   Collateral;   Additional  Collateral.   Pledgor  may
substitute  Collateral under this Pledge Agreement  provided that any Collateral
proposed  for   substitution  is  satisfactory  to  Pledgee  in  Pledgee's  sole
discretion.  As  of  the  date  of  delivery  of  any  Collateral  approved  for
substitution  by Pledgee  pursuant to this Section 15 or  otherwise  approved as
additional  security pursuant to this Pledge Agreement,  Pledgor  represents and
warrants to Pledgee  that (1) Pledgor  will own such  shares,  certificates  and
instruments  free and clear of any right of any other person or entity,  and (2)
Pledgor  will have good and  marketable  title to the shares,  certificates  and
instruments and have the right to pledge such


                                      - 8 -




shares,  certificates  or  instruments  pursuant  to this Pledge  Agreement.  By
delivery  of such  substituted  or  additional  Collateral,  Pledgor  shall have
represented  and warranted that Pledgee has a valid,  perfected,  first priority
security interest in such shares,  certificates and instruments and the proceeds
thereof  free  and  clear of all  liens,  claims  and  rights  of third  parties
whatsoever.  All  documentary,  stamp or other taxes or fees owing in connection
with the issuance,  transfer  and/or pledge of the Collateral or any substituted
or additional Collateral have been paid and will hereafter be paid by Pledgor as
such become due and payable.

         16. Entire Agreement;  Severability. This Pledge Agreement contains the
entire  pledge  agreement  between  Pledgee  and  Pledgor  with  respect  to the
Collateral.  If any of the  provisions  of this Pledge  Agreement  shall be held
invalid or  unenforceable,  this Pledge  Agreement  shall be construed as if not
containing those provisions and the rights and obligations of the parties hereto
shall be construed and enforced accordingly.

         17. Return; Acquittance. Pledgee may at any time deliver any Collateral
to Pledgor  and the  receipt  thereof by  Pledgor  shall be a complete  and full
acquittance  in  respect of the  Collateral  so  delivered,  and  Pledgee  shall
thereafter be discharged from any liability or responsibility therefor.

         18.  References.  As used  herein,  terms in the  singular  include the
plural.  The captions or titles of the sections of this Pledge Agreement are for
convenience  of  reference  only and  shall not  define or limit the  provisions
hereof.

         19.  Choice  of Law.  This  Pledge  Agreement  shall  be  construed  in
accordance with and governed by the laws of the State of California,  and, where
applicable and except as otherwise defined herein,  terms used herein shall have
the meanings given them in the California  Uniform  Commercial Code. Pledgor and
Pledgee each irrevocably and unconditionally  submits to the jurisdiction of the
Superior  Court of the State of California  for the County of Los Angeles or the
United  States  District  Court of the  Central  District of  California,  or if
required,  the Municipal  Court of the State of California for the County of Los
Angeles,  in connection  with any legal action or  proceeding  arising out of or
relating to this Pledge Agreement,  and Pledgor waives any objection relating to
the basis for  personal or in rem  jurisdiction  or to venue which it may now or
hereafter have in any such suit, action or proceeding.

         20. Jury Trial. PLEDGOR AND PLEDGEE WAIVE THE RIGHT TO TRIAL BY JURY IN
ANY ACTION,  SUIT,  PROCEEDING  OR  COUNTERCLAIM  OF ANY KIND  ARISING OUT OF OR
RELATED TO ANY OF THE OBLIGATIONS HEREIN.

         21. Notice. Any written notice, consent or other communication provided
for in this Pledge  Agreement  shall be delivered or sent by  first-class  mail,
with  postage  prepaid,  to the party to be  notified,  to the  mailing  address
specified in the introductory  section hereof.  Such addresses may be changed by
written notice as provided herein.

         22.  Expenses.  Pledgor will  reimburse  Pledgee for all  out-of-pocket
expenses  incurred by Pledgee  arising out of the enforcement of this Agreement,
including without  limitation,  attorneys' fees and costs whether or not suit is
filed.


                                      - 9 -




         23. Indemnification.  Pledgor agrees to pay, and on demand to indemnify
and hold harmless, Pledgee, its successors, assigns and agents, from and against
any and all claims,  damages,  losses,  liabilities,  demands, suits, judgments,
causes  of  action  and  all  legal  proceedings,  whether  civil  or  criminal,
penalties,  fines and other  sanctions,  and any costs and expenses  incurred in
connection  therewith,  including attorneys' fees, which may result from, relate
to or arise  out of this  Pledge  Agreement  or any  Collateral,  including  the
ownership,  purchase,  delivery,  acceptance  or rejection,  use,  possession or
disposition of any item of Collateral,  but not including any claims arising out
of the gross negligence or willful misconduct of Pledgee or its agents.

                  EXECUTED as of November 17, 1997.

PLEDGEE:                                              PLEDGOR:
SANWA BUSINESS CREDIT                                 3-D GEOPHYSICAL, INC.
CORPORATION
By:    /s/ Timothy K. Turner                          By:    /s/ Ronald L. Koons
   --------------------------                            -----------------------

Its:     First Vice President                         Its:    Vice President


                                     - 10 -




                                                    SCHEDULE I

Class of Stock                                                    No. of Shares
- --------------                                                    -------------

1.  Common Stock of Geoevaluaciones, S.A.                            ________
    de C.V. registered in the name of
    3-D Geophysical, Inc.

2.  Common Stock of Procesos Interactivos                            ________
    Avanzados, S.A. de C.V.