<PAGE>
                                                                    Exhibit 10.7




                                  FORM 53-901F

               Section 85 (1) -- Securities Act (British Columbia)
                        (or the equivalent thereof under
                   Canadian Provincial Securities Legislation)

1.       REPORTING ISSUER

         Ivanhoe Mines Ltd. ("Ivanhoe")
         World Trade Centre
         Suite 654 - 999 Canada Place
         Vancouver, British Columbia
         V6C 3E1

2.       DATE OF MATERIAL CHANGE

         July 21, 2003

3.       PRESS RELEASE

         Date of Issuance:    July 21, 2003
         Place of Issuance:   Vancouver, British Columbia

4.       SUMMARY OF MATERIAL CHANGE

         A new independent estimate prepared by AMEC E&C Services Limited
         ("AMEC") of Vancouver, Canada indicates that the Far North Zone at
         Ivanhoe's Turquoise Hill (Oyu Tolgoi) Project now contains estimated
         inferred resources of 618 million tonnes, grading 1.19% copper and 0.10
         grams of gold per tonne ("g/t") of gold, at a 0.60% copper equivalent
         cut off, containing approximately 7.4 million tonnes (16.3 billion
         pounds) of copper and 2.0 million ounces of gold.

5.       FULL DESCRIPTION OF MATERIAL CHANGE

         The new estimate for the Far North Zone at Ivanhoe's Turquoise Hill
         Project was prepared by AMEC in conformance with the requirements set
         out in National Instrument 43-101 ("N143-101") under the direction of
         Dr. Harry Parker, Ch. P. Geol., and Dr. Stephen Juras, P.Geo.,
         independent qualified persons as defined by NI 43-101.

         AMEC's latest estimate is that the Far North Zone at Ivanhoe's
         Turquoise Hill (Oyu Tolgoi) Project contains inferred resources of 618
         million tonnes grading 1.19% copper and 0.10 g/t of gold, at a 0.60%
         copper equivalent cut off, containing approximately 7.4 million tonnes
         (16.3 billion pounds) of copper and 2.0 million ounces of gold.
         Drilling at the Far North Zone also has delineated a high-grade core of
         inferred resources greater than 2% copper equivalent within this larger
         mineralized envelope that is estimated to contain 68.8 million tonnes
         grading 2.92% copper and 0.28 g/t gold.


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                                      - 2 -

        AMEC now estimates that the Turquoise Hill Project contains inferred
        resources totaling 2.4 billion tonnes grading 0.61% copper and 0.14 g/t
        gold, at a 0.30% copper equivalent cut-off, containing approximately
        14.7 million tonnes (32.4 billion pounds) of copper and 11.2 million
        ounces of gold. This represents an increase of 45% in the amount of
        copper and a 24% increase in the amount of gold since AMEC's previous
        estimate issued on February 26, 2003 (the "February 2003 Estimate"). At
        a higher cut-off grade of 0.60% copper equivalent, AMEC estimates an
        inferred resource for the entire project of 941 million tonnes grading
        1.01% copper and 0.21 g/t gold, containing approximately 9.5 million
        tonnes (20.9 billion pounds) of copper and 6.3 million ounces of gold.
        This represents an increase of 29% in the amount of copper and a 41%
        increase in the amount of gold over the previous inferred resource at
        the higher cutoff in the February 2003 Estimate. The project's indicated
        resources are approximately the same as the February 2003 Estimate, as
        Ivanhoe has conducted only a minimal amount of drilling in the Southwest
        Zone since February, 2003. All indicated resources identified to date
        are in the Southwest Zone.

        The Far North deposit and its newly discovered, deeply buried porphyry
        system is one of four co-genetic copper and gold zones delineated to
        date along a five-kilometre-long chain of deposits at Turquoise Hill.
        Analyses of the updated mineral resources for the project, at 0.30% and
        0.60% copper equivalent cut-off grades, are provided in the following
        two tables. As the company's drilling since February has focused on
        expanding and delineating the Far North Zone, AMEC has not updated its
        February resource estimates for the Southwest, South and Central zones.
        The resource estimates for the Southwest, South and Central deposits
        were prepared by AMEC, in February, 2003, and were previously reported
        in the February 2003 Estimate.

        UPDATED TURQUOISE HILL RESOURCE TABLE BY ZONE (BASED ON A 0.30% COPPER
        EQUIVALENT CUT-OFF)1

<TABLE>
<CAPTION>
                      Resources                        Gold          Copper
Zone                  (million           Copper        Grade      Equiv. Grade
                      tonnes)            Grade (%)     (g/t)          (%)                       Contained Metal
                                                                                   -----------------------------------------
                                                                                    Copper      Gold
                                                                                   (million    (million    Copper Equiv.
                                                                                    tonnes)    ounces)    (million tonnes)2
--------------       -----------        ----------    --------      --------       --------    --------    -----------------
<S>                   <C>               <C>          <C>           <C>             <C>         <C>         <C>
Southwest Zone
Indicated              508.9             0.40         0.59          0.78            2.06        9.69        3.98
Inferred               290.8             0.32         0.50          0.64            0.92        4.70        1.86
South Zone
Inferred               270.3             0.39         0.13          0.48            1.07        1.10        1.28
Central Zone
</TABLE>

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                                      - 3 -

<TABLE>
<CAPTION>
                      Resources                        Gold          Copper
Zone                  (million           Copper        Grade      Equiv. Grade
                      tonnes)            Grade (%)     (g/t)          (%)                       Contained Metal
                                                                                   -----------------------------------------
                                                                                    Copper      Gold
                                                                                   (million    (million    Copper Equiv.
                                                                                    tonnes)      ounces)   (million tonnes)2
--------------       -----------        ----------    --------      --------       --------    --------    -----------------
<S>                  <C>                <C>           <C>           <C>            <C>         <C>         <C>
Inferred                 236.8                0.67      0.18          0.79            1.59        1.36        1.86
Far North Zone
Inferred               1,610.5                0.69      0.08          0.74           11.11        3.99        11.93
Grand total:
 Indicated               508.9                0.40      0.59          0.78            2.06        9.69        3.98
Grand total:
 Inferred              2,408.4                0.61      0.14          0.70           14.69       11.15       16.90
</TABLE>


UPDATED TURQUOISE HILL RESOURCE TABLE BY ZONE (BASED ON A 0.60% COPPER
EQUIVALENT CUT-OFF)1

<TABLE>
<CAPTION>
                      Resources                     Gold          Copper
Zone                  (million        Copper        Grade      Equiv. Grade
                       tonnes)        Grade (%)     (g/t)          (%)                       Contained Metal
                                                                                -----------------------------------------
                                                                                 Copper        Gold
                                                                                (million      (million    Copper Equiv.
                                                                                 tonnes)        ounces)   (million tonnes)2
--------------       -----------     ----------    --------      --------       --------       --------    -----------------
<S>                  <C>             <C>           <C>          <C>             <C>             <C>         <C>
Southwest Zone
Indicated             267.0           0.53          0.86         1.08            1.42            7.35         2.88
Inferred              126.6           0.44          0.68         0.87            0.55            2.78         1.10
South Zone
Inferred               48.4           0.61          0.26         0.77            0.29            0.40         0.37
Central Zone
Inferred              147.5           0.84          0.24         0.99            1.24            1.14         1.46
Far North Zone
Inferred              618.4           1.19          0.10         1.26            7.38            1.95         7.77
Grand total:
 Indicated            267.0           0.53          0.86         1.08            1.42            7.35         2.88
Grand total:
 Inferred             940.9           1.01          0.21         1.14            9.50            6.26        10.71

</TABLE>

1.      Copper equivalent grades have been calculated using assumed metal prices
        (US$0.80/lb. for copper and US$350/oz. for gold); %Cu eq. = %Cu + Au
        (g/t) x (11.25/17.64).


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                                      - 4 -
2.      The contained gold and copper represent estimated contained metal in the
        ground and have not been adjusted for the metallurgical recoveries of
        gold and copper. The determination of an adjustment factor to account
        for differences in relative metallurgical recoveries between gold and
        copper will depend upon the completion of definitive metallurgical
        testing.

3.      Resource classifications conform to CIM Standards on Mineral Resources
        and Reserves referred to in National Instrument 43-101. Mineral
        resources that are not reserves do not have demonstrated economic
        viability. An indicated mineral resource is that part of a mineral
        resource for which quantity and grade can be estimated with a level of
        confidence sufficient to allow the application of technical and economic
        parameters to support mine planning and evaluation of the economic
        viability of the deposit. An inferred mineral resource is that part of a
        mineral resource for which quantity and grade can be estimated on the
        basis of geological evidence and limited sampling and reasonably
        assumed, but not verified.

        AMEC's updated estimate for Far North inferred resources incorporated
        results from 100 drill holes.

        Since its discovery in the fall of 2002, the Far North Zone has
        developed into the project's most important deposit. It contains
        approximately 76% of the copper and 36% of the gold in Turquoise Hill's
        total inferred resources defined to date, using a 0.30% copper
        equivalent cut off. Given the open-ended nature of the zone and the
        increasing gold grades recently announced from this area, Ivanhoe has
        directed the main effort of the 13 drill rigs on site on rapidly
        exploring the extent of the high-grade discovery.

        Ivanhoe is reviewing various potential production scenarios that could
        involve early-stage mining, including potential open-pit shell in the
        Southwest Zone and bulk underground mining in a high-grade copper and
        gold core in the Far North Zone. Neither scenario has been subjected to
        an economic analysis, and they are still in the early planning stage.

        New drill holes on the western side of the Far North Zone have
        encountered chalcopyrite and bornite mineralization in a large, quartz
        monzodiorite intrusion underlying the southwestern flank. This zone lies
        500 to 700 metres north of holes drilled early in the Far North
        exploration program and 500 to 1000 metres northwest of the Central
        Zone. The holes were drilled specifically to test the southwestern side
        of a chargeability anomaly (the "IP Anomaly") identified in a recent
        induced polarization survey of the Far North Zone. These early holes
        intersected ignimbrite containing pyrite, chalcopyrite and enargite
        mineralization that overlies and/or flanks the chalcopyrite, bornite and
        chalcocite mineralization in the main, high-grade Far North deposit. One
        of these holes, OTD267, encountered 56 metres grading 0.50% copper and
        0.45 g/t gold starting at 68 metres down hole. OTD188, collared 400
        metres southeast of OTD 267, mid-way to the Central Zone, encountered 42
        metres grading 0.52% copper and 0.13 g/t gold at 132 metres down hole
        and bottomed in 0.88% copper and 0.81 g/t gold at 554 metres due to the
        depth limitation of the drill rig. This sparsely drilled area is broadly
        connected by the western flank of the IP Anomaly. Future exploration
        drilling will target this broad western flank of the IP Anomaly for rear
        surface and deep copper and gold mineralization.

        The increase in gold grades within the high-grade core of the deposit is
        attributable to drill holes in the northern portion of the Far North
        Zone that have encountered strong gold mineralization occurring in
        bornite-rich, quartz stockwork in altered basalt similar to the
        high-grade, Southwest Zone. Numerous intersections of highly mineralized
        porphyry

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                                      - 5 -

        beneath the northern portion of the Far North Zone indicate that a
        deep-seated porphyry is the source of the mineralization.

        The total strike length of the Far North Zone now included in the 0.6%
        copper equivalent inferred resource estimate is approximately two
        kilometres and remains open. The deposit plunges shallowly north and can
        be partitioned into two mineralized zones. The northern portion,
        referred to as the Far North Extension, is hosted by basalt with the
        highest-grade intersections occurring in quartz stock work that replaces
        up to 90% of the basalt. Intense chlorite, hematite after biotite and
        magnetite alteration reinforces the gold-rich porphyry association.

        Drilling for groundwater resources for the project is continuing and
        several aquifers have recently been discovered near the project, the
        largest identified being in a broad regional drainage basin in the
        Galbyn Gobi and Javkhlant areas between 30 to 50 kilometres south of
        Turquoise Hill. Another potential source of the water may be in an
        aquifer in the Gunii Hooloi area, a drainage basin approximately 30
        kilometres north of Turquoise Hill. Assessment of these and other sites
        will continue as part of Ivanhoe's groundwater exploration and resource
        evaluation work.

        Charles Forster, P.Geo., Ivanhoe Mines' Turquoise Hill Manager, a
        qualified person as defined by National Instrument 43-101, supervised
        the preparation of the information upon which this material change
        report is based. SGS Analabs Pty. Ltd. prepares the split core at the
        project site and assays all samples at its facility in Ulaanbaatar,
        Mongolia. Ivanhoe's quality assurance/quality control program is
        monitored by independent consultant Dr Barry Smee, P.Geo., and managed
        on site by Dale Sketchley, M.Sc., P.Geo. Prepared standards and blanks
        are inserted at the sample preparation lab on the project site to
        monitor the quality control of the assay data.

6.      RELIANCE ON SECTION 85 (2) OF THE ACT

        Not applicable

7.      OMITTED INFORMATION

        Not applicable


8.      SENIOR OFFICER

        For further information please contact:

        Beverly Bartlett
        Ivanhoe Mines Ltd.
        Suite 654 - 999 Canada Place
        Vancouver, British Columbia
        V6C 3E1


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         Telephone:  (604) 688-5755

9.       STATEMENT OF SENIOR OFFICER

         The foregoing accurately discloses the material change referred to
         herein.

         DATED at Vancouver, British Columbia this 31st day of July, 2003.


         IVANHOE MINES LTD.



         Per:       "Beverly Bartlett"
                  --------------------------------------------
                   Beverly Bartlett
                   Corporate Secretary