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                                                                  EXHIBIT 10.4

                              EMPLOYMENT CONTRACT

         THIS EMPLOYMENT CONTRACT is made and entered into the 1st day of
June, 1990 by and between FIRST SEISMIC Corporation (COMPANY) and ROGERS E.
BEALL of Houston, Texas (BEALL).

                                   WITNESSETH

         WHEREAS, COMPANY and BEALL desire to reduce to writing their
agreements and understandings relating to the employment of BEALL by COMPANY:

         NOW THEREFORE, IN CONSIDERATION OF THE PREMISES, and the sum of Ten
Dollars ($10.00) to BEALL in hand paid by COMPANY, and other valuable
considerations, the receipt and sufficiency of which are hereby acknowledged,
the parties do contract and agree as follows:

1.       EMPLOYMENT

         The COMPANY agrees to employ BEALL as President and Chief Executive
Officer of the COMPANY at the discretion of the Board of Directors of the
COMPANY, and BEALL agrees to continue such employment and to perform the
duties and discharge the responsibilities hereinafter set out upon the terms
and conditions hereafter set forth.

2.       DUTIES

         As Chief Executive Officer of the COMPANY BEALL shall have the
responsibility of developing and implementing the business plan of the
COMPANY, developing and implementing special projects with the approval of
the Board of Directors and establishing and maintaining working relationships
with the investment and financial community.

         As President of the COMPANY BEALL shall have the responsibility of
directing and supervising all of the activities of the COMPANY both new and
recurring, in its normal course of business. All officers of the COMPANY
shall report directly to BEALL. BEALL shall report directly to the Board of
Directors and BEALL agrees to perform such additional duties relating to his
primary duties as may be assigned to him by the Board of Directors, including
services for entities affiliated with the COMPANY, without additional
compensation.

3.       EXTENT OF SERVICES

         BEALL shall devote such time, attention and energy to the business
of the COMPANY and entities

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affiliated with the COMPANY as may be required by the Board of Directors of
the COMPANY and shall not, during the term of this Agreement, be engaged in
any other business activity if pursued for gain, profit or other pecuniary
advantage. The foregoing shall not be construed as preventing BEALL from
making investments in non-competing businesses or enterprises provided such
investments do not require any personal services from BEALL in the operation
or management of such businesses or enterprises.

4.       COMPENSATION

         As compensation for all services to be rendered by BEALL for the
COMPANY or any of its affiliates, COMPANY agrees to pay BEALL a yearly base
salary equal to one hundred twenty five thousand dollars ($125,000.00)
payable in equal semi-monthly installments. BEALL shall also be entitled to
receive, at the discretion and direction of the Compensation Committee of the
Board of Directors, a bonus to be awarded not less than annually.

         Due to changes in the COMPANY's accounting procedures BEALL hereby
agrees that his ten percent (10%) net profits interest, as set forth in his
prior Employment Contract with the COMPANY, terminated as of January 1, 1990.

         BEALL shall be entitled to participate in the COMPANY's Employee
Stock Option Plan with such participation and exercise of options granted
under the plan to be in compliance with the COMPANY's policies and state and
federal laws where applicable.

5.       COMPANY BENEFITS

         In addition to the above and foregoing compensation, COMPANY shall
make available to BEALL and BEALL shall have the right to participate in:

         A.       A group hospitalization, dental, disability and life insurance
                  plan to the extent same is available to all other full-time
                  employees.

         B.       Participation in COMPANY retirement and other benefit plans to
                  the extent same are available to all other full-time
                  employees.

         C.       Such other benefits as are made available to all other
                  full-time employees. BEALL shall be entitled to annual leave
                  based upon the number of years of service with the COMPANY.

6.       EXPENSES

         COMPANY agrees to reimburse BEALL for all expenses reasonably and
necessarily incurred by him

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in connection with the business of the COMPANY or any of its subsidiaries or
affiliates for meals, lodging, travel and entertainment.

7.       DISCLOSURE OF INFORMATION

         BEALL acknowledges that as President and Chief Executive Officer of
the COMPANY he will have access to confidential and proprietary information
of the COMPANY, of corporations affiliated with the COMPANY and of clients of
COMPANY and that such information constitutes valuable trade secrets of the
COMPANY and such other corporations. BEALL agrees that he will not, during
the term of this Agreement or thereafter, disclose any of such confidential
or proprietary information or trade secrets of the COMPANY, any of its
affiliates, or COMPANY's clients to any other person, firm, corporation,
association or other entity for any reason or for any purpose whatsoever. In
the event of a breach or threatened breach of the provisions of this
paragraph, the COMPANY shall without prejudice to any other remedy to which
it may be entitled, be entitled to an injunction restraining any such breach.

8.       RESTRICTIVE COVENANTS

         BEALL agrees that during the term of his employment with COMPANY he
will not be engaged as principal, agent, representative, consultant,
employee, trustee, or through the agency of any corporation, partnership,
association or agent or agency, in any business that is in competition with
the business conducted by COMPANY. BEALL further agrees that during the term
of his employment by the COMPANY, and for a period of one year (1)
thereafter, he will not own, directly or indirectly, any interest in, nor
will he serve as an officer, director, employee, or consultant to any
business in competition with the business of the COMPANY. Upon receipt by the
COMPANY of a 30-day advance written notice to terminate this Agreement on
amiable terms, the one year (1) restrictive covenant will not apply and then
BEALL may engage in competitive endeavors. BEALL agrees and acknowledges that
the remedy at law for any breach of the foregoing is and will be inadequate
and that COMPANY shall be entitled to injunctive relief to enforce the
foregoing covenants.

9.       TERM AND TERMINATION

         This Agreement shall be effective for the term of three (3) years,
beginning on the 1st day of July, 1990 and terminating on the date which is
thirty six (36) months thereafter, (i) unless BEALL shall sooner die,
whereupon this Agreement shall terminate, or (ii) unless this Agreement shall
be sooner

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terminated by either party, or (iii) unless the COMPANY shall terminate this
Agreement as provided for hereinafter.

         COMPANY may at any time after the commencement of the term of this
Agreement, by giving to BEALL 24 hours prior written notice, terminate this
Agreement if the Board of Directors of COMPANY, in the exercise of good faith
judgment, shall determine that BEALL has been negligent, dishonest, or
derelict in the performance of his duties hereunder.

         The failure of COMPANY to exercise its right to terminate this
Agreement with respect to any one or more of the matters provided for or
referred to in the preceding paragraph shall not be taken or held to be a
waiver by COMPANY of its right to terminate this Agreement in respect of any
subsequent breach.

         This Agreement shall be automatically renewed and extended for
successive one (1) year periods upon the same terms and conditions herein set
forth unless notice of termination shall have been given by either party as
permitted hereunder.

10.      NOTICE

         Any notice which either party hereto may be required or shall desire
to give hereunder shall be deemed to be duly given when delivered personally
or when mailed by certified or registered mail, postage prepaid, to the party
to whom such notice is being given at the address indicated below, or any
such other address or addresses of which such party shall have been given
written notice:

         COMPANY                      FIRST SEISMIC Corporation
                                      c/o Rogers E. Beall
                                      600 17th Street, Suite 400
                                      Denver, Colorado 80202

         BEALL                        Rogers. E. Beall
                                      c/o FIRST SEISMIC Corporation
                                      10375 Richmond Ave., Suite 1100
                                      Houston, Texas 77042

11.      MISCELLANEOUS

         The descriptive headings of the several sections of this Agreement
are inserted for the convenience of the parties only and do not constitute a
part of this Agreement.

         This Agreement is made and entered into in Denver, Colorado, and all
rights and obligations of the parties hereunder shall be construed and
interpreted under and pursuant to the laws of the State of Colo-

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rado.

         This Agreement supersedes all prior or contemporaneous agreements or
understandings between the parties hereto, whether written or oral.

         This Agreement shall inure to the benefit of and be binding upon the
parties hereto and their respective heirs, legal representatives, successors
and assigns; provided, however, that this Agreement shall be deemed to be
personal to BEALL and shall not be assignable by BEALL.

         IN WITNESS WHEREOF, the parties hereto have duly executed this
Agreement on the date first above written.

                                FIRST SEISMIC Corporation


                                BY: /s/ [ILLEGIBLE]
                                   -----------------------------------------

                                TITLE:  TREASURER
                                      --------------------------------------

                                BY: /s/ Rogers E. Beall
                                   -----------------------------------------
                                   ROGERS E. BEALL

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