EXHIBIT 4.18

              Guarantee Agreement, dated July 8, 2005, executed by

                          Marsa Gold Corp. in favor of

                                 0724000 BC Ltd.



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                               GUARANTEE AGREEMENT


This Guarantee Agreement is made as of the 8th day of July 2005 between:

MARSA GOLD CORP., a Kyrgyz limited  liability  company with an address of Kyrgyz
Republic, Bishkek, microregion 11, 6-46 (the "Guarantor"); and

CENTRASIA  MINING CORP.  (FORMERLY  "MAGELLAN GOLD CORP."),  a British  Columbia
corporation  with an address of 300 - 1055 W.  Hastings St.,  Vancouver,  BC V6E
2E9, Canada (the "Creditor"),


                  WHEREAS the  Guarantor  is the sole  participant  of BULAKASHU
MINING COMPANY LTD (the "Debtor");

                  WHEREAS the Creditor has lent the Debtor  US$110,000  to date;
and

                  WHEREAS  the  Creditor  may lend the  Debtor  additional  sums
pursuant to an  agreement of even date between the  Guarantor,  the Debtor,  the
Creditor,   Baradero  Resources  Limited  and  Magellan  Gold  (BVI)  Inc.  (the
"Bulakashu  Option  Agreement"),  and the Creditor has refused to do so without,
among other things, a personal guarantee of repayment from the Guarantor.

                  NOW, THEREFORE, FOR GOOD AND VALUABLE CONSIDERATION given, the
receipt and sufficiency of which is hereby  acknowledged,  the Guarantor  hereby
guarantees  payment to the  Creditor  of all debts and  liabilities,  present or
future, direct or indirect, absolute or contingent,  matured or not, at any time
owing by the Debtor to the  Creditor  or  remaining  unpaid by the Debtor to the
Creditor,  whether incurred by or arising from any agreement or dealings between
the Creditor and the Debtor  (including the Bulakashu Option Agreement) or by or
from any agreement or dealings with any third party by which the Creditor may be
or become in any manner whatsoever a creditor of the Debtor or however otherwise
incurred or arising  anywhere within or outside the country where this Guarantee
Agreement  is executed  and whether the Debtor be bound alone or with another or
others and whether as  principal  or surety  (such debts and  liabilities  being
hereinafter called the "Liabilities").

                  AND  THE  GUARANTOR  HEREBY  COVENANTS  AND  AGREES  WITH  THE
CREDITOR AS FOLLOWS:

1.                The   Creditor   may   grant   time,   renewals,   extensions,
indulgences, releases and


discharges  to,  take  securities  (which  word as used  herein  includes  other
guarantees)  from and give the same and any or all  existing  securities  up to,
abstain from taking  securities from or from perfecting  securities of, cease or
refrain from giving credit or making loans or advances to,  accept  compositions
from and otherwise  deal with,  the Debtor and others and with all securities as
the Creditor may in its absolute  discretion  see fit  (including the release of
the Guarantor or other sureties),  and may apply all moneys at any time received
from the  Debtor  or others  or from  securities  upon such part or parts of the
Liabilities as the Creditor in its absolute  discretion sees fit, and change any
such  application  in whole or in part from time to time as the Creditor may see
fit, the whole  without in any way limiting or  lessening  the  liability of the
Guarantor  under this Guarantee  Agreement , and no loss of or in respect of any
securities  received  by  the  Creditor  from  the  Debtor  or  others,  whether
occasioned by the fault of the Creditor or otherwise,  shall in any way limit or
lessen the liability of the Guarantor  under this Guarantee  Agreement.

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2.                This Guarantee  Agreement shall be a continuing  guarantee and
shall cover all the  Liabilities,  and it shall apply to and secure any ultimate
balance due or remaining unpaid to the Creditor.

3.                The  Creditor  shall  not be bound  to  exhaust  its  recourse
against  the Debtor or others or any  securities  it may at any time hold before
being entitled to payment from the Guarantor of the  Liabilities.  The Guarantor
renounces all benefits of discussion and division.

4.                The  Guarantor  may,  by notice in  writing  delivered  to the
office of the Creditor receiving this instrument,  determine its liability under
this  Guarantee  Agreement in respect of  Liabilities  incurred or arising after
receipt  of  such  notice  but not in  respect  of any  Liabilities  theretofore
incurred  or arising  even  though not then  matured,  provided,  however,  that
notwithstanding  receipt  of any  such  notice  the  Creditor  may  fulfill  any
requirements of the Debtor based on agreements  express or implied made prior to
the receipt of such  notice and any  resulting  Liabilities  shall be covered by
this Guarantee Agreement.

5.                This Guarantee Agreement shall not be affected by:

          (a)     any change in the name or the  structure of the Debtor;


          (b)     the acquisition of the Debtor's  business by a third party;

          (c)     any change  whatsoever  in the objects,  capital  structure or
                  constitution of the Debtor;

          (d)     the  Debtor's   business   being   amalgamated   with  another
                  corporation; or

          (e)     any defect in,  omission from,  failure to file or register or
                  defective filing or registration of any instrument under which
                  the Creditor has taken any security or collateral  for payment
                  of any of the  Liabilities or performance or observance of any
                  obligation of the Debtor,  the Guarantor  (whether  under this
                  Guarantee  Agreement or  otherwise) or of any other person who
                  is or may become liable in respect of the Liability;

                  but shall,  notwithstanding  the  happening  of any such event
                  continue to apply to all the Liabilities  whether  theretofore
                  or thereafter  incurred or arising.  (In this  instrument  the
                  word "Debtor"  shall  include every such firm and  corporation
                  described in paragraphs (b), (c) and (d) above).

6.                This Guarantee  Agreement shall not be considered as wholly or
partially  satisfied by the payment or  liquidation  at any time or times of any
sum or sums of money for the time being due or remaining unpaid to the Creditor,
and all  dividends,  compositions,  proceeds  of  security  valued and  payments
received by the Creditor from the Debtor or from others or from estates shall be
regarded for all purposes as payments in gross  without any right on the part of
the  Guarantor  to claim in  reduction  of the  liability  under this  Guarantee
Agreement the benefit of any such dividends, compositions,  proceeds or payments
or any securities  held by the Creditor or proceeds  thereof,  and the Guarantor
shall have no right to be  subrogated  in any rights of the  Creditor  until the
Creditor shall have received payment in full of the Liabilities.


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7.                All moneys, advances, renewals and credits in fact borrowed or
obtained  from the  Creditor  shall be deemed  to form part of the  Liabilities,
notwithstanding  any lack or  limitation  of status or of power,  incapacity  or
disability of the Debtor or of the  directors,  partners or agents  thereof,  or
that the Debtor may not be a legal or suable entity, or any irregularity, defect
or informality in the borrowing or obtaining of such moneys, advances,  renewals
or credits,  the whole  whether  known to the Creditor or not; and any sum which
may not be recoverable from the Guarantor as guarantor shall be recoverable from
the  Guarantor and each of them as sole or principal  debtor in respect  thereof
and shall be paid to the Creditor on demand with interest as aforesaid.

8.                This  Guarantee  Agreement  is  in  addition  to  and  not  in
substitution for any other guarantee,  by whomsoever  given, at any time held by
the Creditor,  and any present or future  obligation to the Creditor incurred or
arising  otherwise  than under a guarantee of the Guarantor or any of them or of
any other obligant,  whether bound with or apart from the Debtor,  excepting any
guarantee surrendered for cancellation on delivery of this instrument.

9.                The Guarantor  shall be bound by any account  settled  between
the  Creditor  and  the  Debtor,  and if no such  account  has  been so  settled
immediately before demand of payment under this Guarantee  Agreement any account
stated by the Creditor shall be accepted by the Guarantor as conclusive evidence
of the amount which at the date of the account so stated is due by the Debtor to
the Creditor or remains unpaid by the Debtor to the Creditor.

10.               This Guarantee Agreement shall be operative and binding on the
Guarantor, and possession of this instrument by the Creditor shall be conclusive
evidence  against the Guarantor that this instrument was not delivered in escrow
or  pursuant  to any  agreement  that  it  should  not be  effective  until  any
conditions precedent or subsequent had been complied with.

11.               The  demand  for   payment   shall  be  deemed  to  have  been
effectually  made upon the  Guarantor  if and when an envelope  containing  such
demand, addressed to the Guarantor at the address last known to the Creditor, is
posted,  postage  prepaid,  in the post office or is delivered to the Guarantor,
and, in the event of the death of the Guarantor,  demand of payment addressed to
any of the Guarantor's heirs, executors, administrators or legal representatives
at the  address  of the  addressee  last  known to the  Creditor  and  posted or
delivered as aforesaid shall be deemed to have been effectively made upon all of
them. All payments  hereunder shall be made to the Creditor at the office of the
Creditor.

12.               This Guarantee  Agreement  covers all  agreements  between the
parties  hereto  concerning  this Guarantee  Agreement,  and none of the parties
shall be bound by any  representation  or promise  made by any  person  relative
thereto which is not expressly embodied herein.

13.               This Guarantee Agreement shall be governed by and construed in
accordance with the laws of British Columbia.  All disputes arising out of or in
connection  with this  Guarantee  Agreement,  or in respect of any defined legal
relationship associated therewith or derived therefrom, shall be referred to and
finally  resolved by arbitration in the English language using a sole arbitrator
under the rules of the British  Columbia  International  Commercial  Arbitration
Centre.  The  appointing  authority  or tribunal  shall be the British  Columbia
International  Commercial  Arbitration Centre. The case shall be administered by
the British


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Columbia  International  Commercial  Arbitration  Centre in accordance  with its
Rules. The place of arbitration shall be Vancouver,  British  Columbia,  Canada.
Provided  always that nothing herein  contained  shall prevent the Creditor from
proceeding  at its  election  in the  Courts of any other  jurisdiction  and the
Guarantor hereby irrevocably submits to each such jurisdiction, acknowledges the
competence  of each and the  convenience  and propriety of the venue thereof and
agrees to be bound by any judgment  thereof and not to seek,  and hereby waives,
any  review  of the  merits  of  such a  judgment  by the  Courts  of any  other
jurisdiction  and also hereby waives any and all objections which it may have to
each such jurisdiction.

14.               So long as any of the Liabilities remain unpaid or outstanding
the Guarantor assumes all  responsibility  for being and keeping itself informed
of the financial  condition of the Debtor and of all circumstances  bearing upon
the nature,  scope and extent of the risk which the Guarantor assumes and incurs
under this Guarantee Agreement .

15.               This  Guarantee  Agreement  shall  extend  to and enure to the
benefit of the Creditor and its successors and assigns,  and shall extend to and
be binding upon the Guarantor and the heirs,  executors,  administrators,  legal
representatives,  successors and assigns of the Guarantor or each of them or any
of them,  as the case may be.  16.  The  Guarantor  hereby  waives all rights to
receive from the Creditor a copy of any financing  statement,  financing  change
statement or  verification  statement  filed at any time or from time to time in
respect of this Guarantee Agreement.

GIVEN UNDER SEAL at Bishkek, Kyrgyz Republic, on the day and year above written.

MARSA GOLD CORP.


Per:  /s/ Dmitriy Vedeshkin-Ryabov
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         Authorized Signatory

Bulakashu Mining Company LTD, the "Debtor" referred to above, hereby consents to
the terms of the foregoing Guarantee Agreement.



BULAKASHU MINING COMPANY LTD


Per:  /s/ Oleg Kim
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         Authorized Signatory


CENTRASIA MINING CORP.


Per: /s/ Douglas Turnbull
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         Authorized Signatory