<PAGE>
                                                                   EXHIBIT 10.16

                           NORD RESOURCES CORPORATION

                            DEBT CONVERSION AGREEMENT

THIS DEBT CONVERSION AGREEMENT (the "Agreement") is entered into and made
effective as of the 16th day of April, 2004 (the "Effective Date"), by and
between MRPGEO, LLC, an limited liability company organized and existing under
the laws of the State of Arizona (the "Investor"), and NORD RESOURCES
CORPORATION, a corporation organized and existing under the laws of the State of
Delaware (the "Company").

                                    RECITALS

     WHEREAS, the Investor is an owner of certain leasehold rights and mining
claims as described in Exhibit A and Exhibit B of that certain Option to
Purchase the "Coyote Springs" Property, dated January 28, 2004 (the "Property
Agreement") by and among the Company, the Investor, Thornwell Rogers ("Rogers")
and South Branch Resources LLC ("SBRLLC" and, together with Rogers and the
Investor, the "Sellers"), wherein the Company was granted an option (the
"Option") to acquire said leasehold rights and mining claims pertaining to the
Coyote Springs property located in Graham County, Arizona (the "Property"); and

     WHEREAS, in accordance with the terms of the agreement pertaining to the
Option (the "Property Agreement"), the Company is obligated to pay to the
Sellers 199,998 shares of its capital common stock, having a par value of One
Cent ($0.01) per share (a "Share"), of which 66,666 Shares are payable to the
Investor immediately (the "Initial Shares"); and

     WHEREAS, under the terms of the Property Agreement, and at the election of
the Sellers, they may each elect to receive on the first, second, third, and
fourth anniversaries of the Agreement either: (i) an additional 66,664 Shares in
the aggregate in four installments of 16,666 Shares each or (ii) $70,000 in
cash, in four installments of $15,000, $16,670, $18,330 or $20,000,
respectively, as well as Shares or cash, at the Seller's option, payable on the
fifth anniversary of the Agreement having a dollar amount equal to $533,335 each
(these Shares to be paid under the Agreement, other than the Initial Shares,
being hereinafter referred to as the "Payment Shares"); and

     WHEREAS, under the terms of the Property Agreement, each of the Sellers is
to be granted additional options (the "Share Options") to purchase an additional
99,999 common shares (the "Underlying Shares") in the aggregate, in three
installments of 33,333 Underlying Shares each, for a purchase price equal to 15%
below the quoted closing price for the Company's common stock as reported by the
stock market in which its shares are then publicly traded, on (i) the effective
date of this Agreement; (ii) the date which is twenty-four (24) months from the
date hereof; and the date which is forty-eight (48) months from the date hereof,
respectively, each of which will expire on the date that


                                      -1-

<PAGE>

is thirty-six (36) months from the individual dates on which such options were
issued; and

     WHEREAS, this Agreement shall serve as the subscription document to effect
the purchase of the Initial Shares and the issuance of the Share Options
described above, and shall serve as the basis for exercise of the remaining
Payment Shares and Underlying Shares (collectively referred to herein as the
"Optioned Shares"), if and to the extent elected in the sole discretion of the
Investor.

                                    AGREEMENT

     NOW, THEREFORE, in consideration of the foregoing premises, and the mutual
promises and covenants contained in this Agreement, and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties, intending to be legally bound, hereby agree as
follows:

1.   Subscription for Initial Shares. By its execution below, the Investor
     hereby irrevocably subscribes for and accepts, in satisfaction of the
     requirement of the Company to provide the Initial Shares, 66,666 Shares.
     Upon receipt of this originally-signed Agreement, the Company shall deliver
     to the Investor a certificate evidencing the ownership of the Initial
     Shares, which Initial Shares shall be validly-issued, fully-paid and
     non-assessable, and free and clear of any liens, security interests,
     charges, assessments and defects in title (a "Lien"). The certificate shall
     be recorded on the books and records of the Company in the name of Michael
     R. Powlowski, to whom the right to receive all Shares issuable hereunder
     has been assigned by the Investor.

2.   Grant of Options for Optioned Shares. By its execution of this Agreement,
     the Company hereby grants to the Investor the option to purchase up to the
     maximum amount of Payment Shares and Underlying Shares referenced in the
     Recitals to this Agreement. To the extent that the Investor shall desire to
     exercise his option with respect to some or all of the Optioned Shares on
     or before the dates indicated in the Property Agreement, he may do so by
     submitting (on each date that an exercise of the option rights granted
     hereunder is made) to the Company a signed original Updating Subscription
     Form, in the form attached as Exhibit A to this Agreement (an "Updating
     Form") and, in the case of the Underlying Shares, accompanied by a check in
     the amount of the exercise price per share times the number of Underlying
     Shares being purchased thereunder, following the receipt of which the
     Company shall deliver to the Investor a certificate representing the amount
     of Shares exercised for and reflected in the applicable Updating Form,
     which Shares shall upon delivery to the Investor be validly-issued,
     fully-paid and non-assessable, and free and clear of all Liens. Each
     subsequent certificate shall be recorded as set forth in Section 1 above,
     unless otherwise requested by the Investor prior to the issuance thereof by
     the Company as contemplated herein.


                                      -2-

<PAGE>

3.   Legends on Stock Certificates. Each certificate representing Shares shall
     contain the following legends on the reverse of such certificate:

          THIS SECURITY HAS NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE
          COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"),
          NOR ANY STATE SECURITIES DEPARTMENT, IN RELIANCE UPON THE EXEMPTION
          FROM REGISTRATION PROVIDED IN SECTION 4(2) OF THE ACT AND SECTION
          44-1844(1) OF THE ARIZONA REVISED STATUTES. AS SUCH, THE PURCHASE OF
          THIS SECURITY WAS NECESSARILY WITH THE INTENT OF INVESTMENT AND NOT
          WITH A VIEW FOR DISTRIBUTION. THEREFORE, ANY SUBSEQUENT TRANSFER OF
          THIS SECURITY OR ANY INTEREST THEREIN WILL BE UNLAWFUL UNLESS IT IS
          REGISTERED UNDER THE ACT OR UNLESS AN EXEMPTION FROM REGISTRATION IS
          AVAILABLE. FURTHERMORE, IT IS UNLAWFUL TO CONSUMMATE A SALE OR
          TRANSFER OF THIS SECURITY, OR ANY INTEREST THEREIN, WITHOUT THE
          OPINION OF COUNSEL FOR THE COMPANY THAT THE PROPOSED TRANSFER OR SALE
          DOES NOT AFFECT THE EXEMPTIONS RELIED UPON BY THE COMPANY IN
          ORIGINALLY DISTRIBUTING THIS SECURITY.

4.   Investor Representations. The Investor hereby represents and warrants to
     the Company, as of the date hereof, the following:

     (a)  the Investor is a limited liability company organized and existing
          under the laws of the State of Arizona, and has full power and
          authority to enter into and perform this Agreement, which Agreement,
          once executed by the Investor, shall be the valid and binding
          obligation of such party, enforceable against such party by any court
          of competent jurisdiction in accordance with its terms;

     (b)  the individual signing this Agreement for and on behalf of the
          Investor is the duly authorized Managing Member of the Investor, and
          has full power and authority to enter into and execute this Agreement
          for and on behalf of the Investor and to make the representations and
          warranties relied upon by the Company in issuing Shares hereunder;

     (c)  with respect to all Shares being acquired by the Investor and/or Mr.
          Powlowski hereunder:

          (i)  each of the Investor and Mr. Powlowski is and/or will be
               acquiring the Shares for his or its own account, and not with a
               view toward the subdivision, resale, distribution, or
               fractionalization thereof; neither the Investor nor Mr. Powlowski
               has any contract, undertaking, or arrangement with any person to
               sell, transfer, or otherwise dispose of the Shares (or any
               portion thereof hereby subscribed for), and has no present
               intention to enter into any such contract, undertaking, agreement
               or arrangement;


                                      -3-

<PAGE>

          (ii) the subscription for Shares by the Investor and/or Mr. Powlowski
               hereunder is not the result of any form of general solicitation
               or general advertising;

          (iii) each of the Investor and Mr. Powlowski hereby acknowledge that:
               (A) the offering of the Shares has been made only through direct,
               personal communication between the Investor and the Company; (B)
               each of the Investor and Mr. Powlowski has had full access to
               material concerning the Company's planned business and
               operations, which material was furnished or made available to
               each of the Investor and Mr. Powlowski, as requested, by officers
               or representatives of the Company; (C) the Company has given each
               of the Investor and Mr. Powlowski the opportunity to ask any
               questions and obtain all additional information desired in order
               to verify or supplement the material so furnished; and (D) each
               of the Investor and Mr. Powlowski understands and acknowledges
               that the Shares are subject to substantial restrictions upon the
               transfer thereof, and that a purchaser of the Shares must be
               prepared to bear the economic risk of such investment for an
               indefinite period;

          (iv) each of the Investor and Mr. Powlowski understands that the
               Shares have not been registered under the Securities Act of 1933
               (the "Act") or any state securities act (nor passed upon by the
               SEC or any state securities commission), and that the Shares may
               never be registered or qualified by each of the Investor and/or
               Mr. Powlowski under federal or state securities laws solely in
               reliance upon an available exemption from such registration or
               qualification, and hence such Shares cannot be sold unless they
               are subsequently so registered or qualified, or are otherwise
               subject to any applicable exemption from such registration
               requirements; and

          (v)  each of the Investor and Mr. Powlowski further understand and
               acknowledge that (A) the Shares have not been registered with the
               Arizona Securities Commission, and are being issued to Mr.
               Powlowski in that State pursuant to and in reliance upon the
               exemption from such registration provided by Section 44-1844 of
               the Arizona Revised Statutes as a sale of securities within the
               State not involving any public offering; (B) the Shares may not
               be resold to any person unless and until such registration has
               occurred or pursuant to an exemption from registration permitted
               by


                                      -4-

<PAGE>

               the applicable securities laws and regulations of the State of
               Arizona; and (C) that there are substantial restrictions on
               transfer of the Shares, as set forth herein and by legend on the
               reverse side of every certificate evidencing the ownership of the
               Shares;

     (d)  each of the Investor and Mr. Powlowski is either (i) an "accredited
          investor" as such term is defined in Rule 501 of Regulation D
          promulgated by the Securities and Exchange Commission under the Act,
          or (ii) is a sophisticated investor meeting the minimum standards for
          an investment in an unregistered security under applicable state and
          federal securities laws and possessing such knowledge and experience
          as is necessary, individually or together with such person's financial
          or investment advisors, to make a determination as to the merits and
          risks of investing in securities generally, and in the Shares; and

     (e)  each of the Investor and Mr. Powlowski have been advised to consult
          with an attorney regarding legal matters concerning the purchase and
          ownership of the Shares, and with a tax advisor regarding the tax
          consequences of purchasing such Shares.

5.   Miscellaneous Provisions.

     (a)  Notices. All notices, requests, demands and other communications to be
          given hereunder shall be in writing and shall be deemed to have been
          duly given on the date of personal service or transmission by fax if
          such transmission is received during the normal business hours of the
          addressee, or on the first business day after sending the same by
          overnight courier service or by telegram, or on the third business day
          after mailing the same by first class mail, or on the day of receipt
          if sent by certified or registered mail, addressed as set forth below,
          or at such other address as any party may hereafter indicate by notice
          delivered as set forth in this Section 5(a):

          If to the Company:    Nord Resources Corporation
                                9947 North Calle Solano
                                Tucson, AZ 85737
                                Attn: Erland Anderson, President

          If to the Investor:   MRGPEO, LLC
                                1700 E. Lakeside Dr., No. 57
                                Gilbert, AZ 85234
                                Attn: Mr. Michael R. Powlowski

     (b)  Entire Agreement. This Agreement constitutes the entire and final
          agreement and understanding between the parties with respect to the


                                      -5-

<PAGE>

          issuance of securities by the Company to the Investor in satisfaction
          of its requirements under the Property Agreement, and supersedes any
          and all prior oral or written agreements, statements, representations,
          warranties or understandings between the parties, all of which are
          merged herein and superseded hereby. Notwithstanding the foregoing,
          nothing in this Agreement is intended to modify, alter, repeal,
          replace or otherwise affect the legal rights and obligations among and
          between the parties with respect to any other aspect of the Property
          Agreement.

     (c)  Counterparts; Facsimiles. This Agreement may be executed in one or
          more counterparts, each of which shall be deemed an original, but all
          of which together shall constitute one and the same instrument.
          Facsimiles of original signatures shall be deemed original signatures
          for all purposes.

     (d)  Further Documents and Acts. Each party agrees to execute such other
          and further documents and to perform such other and further acts as
          may be reasonably necessary to carry out the purposes and provisions
          of this Agreement.

     (e)  Governing Law; Venue. This Agreement shall be governed by and
          construed in accordance with the internal laws of the State of Arizona
          applicable to contracts to be performed within that state, without
          giving effect to the law of conflicts of laws applied thereby. In the
          event either party shall be forced to bring any legal action to
          protect or defend its rights hereunder, then the prevailing party in
          such proceeding shall be entitled to reimbursement from the
          non-prevailing party of all fees, costs and other expenses (including,
          without limitation, the reasonable expenses of its attorneys) in
          bringing or defending against such action.

     (f)  Severable Provisions. The provisions of this Agreement are severable,
          and if any one or more provisions is determined to be illegal,
          indefinite, invalid or otherwise unenforceable, in whole or in part,
          by any court of competent jurisdiction, then the remaining provisions
          of this Agreement and any partially unenforceable provisions to the
          extent enforceable in the pertinent jurisdiction, shall continue in
          full force and effect and shall be binding and enforceable on the
          parties.


                                      -6-

<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
and year first written above.

THE COMPANY:

NORD RESOURCES CORPORATION:             ATTEST:


By: /s/ Erland Anderson                 By: /s/ Kathy Glidewell
    ---------------------------------       ------------------------------------
    Erland Anderson                         Kathy Glidewell
    President                               Asst. Secretary


THE INVESTOR:

MRGPEO, LLC:                            WITNESS:


By: /s/ Michael R. Pawlowski            By: /s/ J. Gudgeon
    ---------------------------------       ------------------------------------
    Managing Member


MICHAEL R. POWLOWSKI,
in his individual capacity:


By: /s/ Michael R. Powlowski
    ---------------------------------


                                      -7-

<PAGE>

                                    EXHIBIT A
                            TO SUBSCRIPTION AGREEMENT

                           UPDATING SUBSCRIPTION FORM

            [A Separate Form To Be Completed For Each Exercise Date]

The Undersigned, by signing in the space provided below, does hereby certify to
Nord Resources Corporation as follows (capitalized terms used but not otherwise
defined in this Form have the meanings given to them in the Subscription
Agreement of which this Form constitutes a part):

1.   reference is made to that certain Subscription Agreement (the "Subscription
     Agreement"), dated as of April 16, 2004, between the Undersigned (the
     "Investor") and Nord Resources Corporation (the "Company"), of which this
     Updating Subscription Form (the "Subscription Form") is a part;

2.   in accordance with the terms of the Subscription Agreement, the Undersigned
     hereby irrevocably exercises its option and subscribes for ______________
     shares of the Common Stock of the Company (the "Payment Shares"), in
     partial exercise of the Investor's option to receive Optioned Shares and/or
     purchase Underlying Shares pursuant to Section 2 of the Subscription
     Agreement;

3.   by executing and delivering this Subscription Form to the Company, the
     Investor hereby makes and confirms each of the representations and
     warranties made by the Investor in Section 4 of the Subscription Agreement,
     which representations and warranties are hereby incorporated by reference
     herein in their entirety as an integral part of this Subscription Form, are
     expressly true and correct as of the date of this Subscription Form, and
     upon which the Company may rely in issuing the Payment Shares to the
     Investor without registration and pursuant to exemption therefrom under
     federal and Arizona state securities laws as contemplated by the
     Subscription Agreement; and

4.   upon the execution and delivery of this Subscription Form to the Company,
     calling for such number of Payment Shares as the Investor may then be
     entitled to pursuant to the Subscription Agreement, the Company shall issue
     and deliver to the Investor a certificate evidencing such number of Payment
     Shares and/or Underlying Shares as owned of record by MRGPEO, LLC and/or
     Michael R. Powlowski, as indicated by the Investor, and such Payment Shares
     shall be validly-issued, fully-paid, non-assessable and free and clear of
     any Liens thereon.

Name of Investor:                 MRGPEO, LLC


Signature of Investor:
                                  ------------------------------
                                  Managing Member

Date of this Subscription Form:
                                  ------------------------------


                                      -8-