Exhibit
        4.3

       

      THIS
        DEBENTURE AND THE COMMON SHARES ISSUABLE UPON CONVERSION OF THIS DEBENTURE
        HAVE
        NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY
        STATE
        SECURITIES LAWS. THIS NOTE AND THE COMMON SHARES ISSUABLE UPON CONVERSION
        OF
        THIS NOTE MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE
        ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THIS DEBENTURE UNDER
        SAID
        ACT AND ANY APPLICABLE STATE SECURITIES LAWS OR AN OPINION OF COUNSEL REASONABLY
        SATISFACTORY TO TRIANGLE PETROLEUM CORPORATION THAT SUCH REGISTRATION IS
        NOT
        REQUIRED.

       

      CONVERTIBLE
        DEBENTURE

       

      FOR
        VALUE
        RECEIVED, Triangle Petroleum Corporation, a Nevada corporation (the
“Borrower”),
        promises to pay to Bank Sal. Oppenheim jr. & Cie., (Schweiz) AG (the
“Holder”)
        or its
        registered assigns or successors in interest, the sum of Two Million Five
        Hundred Thousand Dollars ($2,500,000), together with any accrued and unpaid
        interest hereon, on December 28, 2008 (the “Maturity
        Date”)
        if not
        sooner paid.

       

      Capitalized
        terms used herein without definition shall have the meanings ascribed to
        such
        terms in that certain Securities Purchase Agreement dated as of December
        28,
        2005, between Borrower and the Holder (as amended, modified or supplemented
        from
        time to time, the “Purchase
        Agreement”).

       

      The
        following terms shall apply to this Debenture:

       

      ARTICLE
        I 

      INTEREST
        & AMORTIZATION

       

      1.1. Contract
        Rate.
        Subject
        to Sections 4.11 and 6.7 hereof, interest payable on this Debenture shall
        accrue
        at a rate per annum equal to seven and one-half percent (7.5%) (the
“Contract
        Rate”).
        

       

      1.2. Payments.
        Payment
        of the aggregate principal amount outstanding under this Debenture (the
“Principal
        Amount”),
        together with all accrued interest thereon shall be made on the Maturity
        Date.

       

      ARTICLE
        II 

      CONVERSION
        REPAYMENT 

       

      2.1. Optional
        Conversion.
        Subject
        to the terms of this Article II, the Holder shall have the right, but not
        the
        obligation, at any time until the Maturity Date, or thereafter during an
        Event
        of Default and to convert all or any portion of the outstanding Principal
        Amount
        and/or accrued interest and fees due and payable into fully paid and
        nonassessable shares of the Common Stock at the Fixed Conversion Price. The
        shares of Common Stock to be issued upon such conversion are herein referred
        to
        as the “Conversion
        Shares.”
        The
“Fixed
        Conversion Price”
        shall
        mean $4.00.

       

      
        
           

        

        
           

          
            

          

        

        
           

        

      

      2.2. Conversion
        Limitation.
        Notwithstanding anything contained herein to the contrary, the Holder shall
        not
        be entitled to convert pursuant to the terms of this Debenture an amount
        that
        would be convertible into that number of Conversion Shares which would exceed
        the difference between the number of shares of Common Stock beneficially
        owned
        by such Holder or issuable upon exercise of the warrant and the option held
        by
        such Holder and 4.99% of the outstanding shares of Common Stock of Borrower.
        For
        the purposes of the immediately preceding sentence, beneficial ownership
        shall
        be determined in accordance with Section 13(d) of the Exchange Act and
        Regulation 13d-3 thereunder. The Conversion Shares limitation described in
        this
        Section 3.2 shall automatically become null and void without any notice to
        any
        Borrower upon the occurrence and during the continuance beyond any applicable
        grace period of an Event of Default, or upon 65 days prior notice to
        Borrower.

       

      2.3. Mechanics
        of Holder’s Conversion.
        In the
        event that the Holder elects to convert this Debenture into Common Stock,
        the
        Holder shall give notice of such election by delivering an executed and
        completed notice of conversion (“Notice
        of Conversion”)
        to
        Borrower and such Notice of Conversion shall provide a breakdown in reasonable
        detail of the Principal Amount, accrued interest and fees that are being
        converted. On each Conversion Date (as hereinafter defined) and in accordance
        with its Notice of Conversion, the Holder shall make the appropriate reduction
        to the Principal Amount, accrued interest and fees as entered in its records
        and
        shall provide written notice thereof to the Borrower on the Conversion Date.
        Each date on which a Notice of Conversion is delivered or telecopied to Borrower
        in accordance with the provisions hereof shall be deemed a Conversion Date
        (the
“Conversion
        Date”).
        A
        form of Notice of Conversion to be employed by the Holder is annexed hereto
        as
Exhibit
        A.
        Pursuant to the terms of the Notice of Conversion, Borrower will issue
        instructions to the transfer agent accompanied by an opinion of counsel to
        Borrower of the Notice of Conversion and shall cause the transfer agent to
        transmit the certificates representing the Conversion Shares to the Holder
        by
        physical delivery or crediting the account of the Holder’s designated broker
        with the Depository Trust Corporation (“DTC”)
        through its Deposit Withdrawal Agent Commission (“DWAC”)
        system
        within three (3) business days after receipt by Borrower of the Notice of
        Conversion (the “Delivery
        Date”).
        In
        the case of the exercise of the conversion rights set forth herein the
        conversion privilege shall be deemed to have been exercised and the Conversion
        Shares issuable upon such conversion shall be deemed to have been issued
        upon
        the date of receipt by Borrower of the Notice of Conversion. The Holder shall
        be
        treated for all purposes as the record holder of such Common Stock, unless
        the
        Holder provides Borrower written instructions to the contrary.Late
        Payments.
        Each
        Borrower understands that a delay in the delivery of the shares of Common
        Stock
        in the form required pursuant to this Article beyond the Delivery Date could
        result in economic loss to the Holder. As compensation to the Holder for
        such
        loss, the each Borrower agrees to jointly and severally pay late payments
        to the
        Holder for late issuance of such shares in the form required pursuant to
        this
        Article II upon conversion of the Debenture, in the amount equal to $500
        per
        business day after the Delivery Date. Each Borrower shall pay any payments
        incurred under this Section in immediately available funds upon demand.


       

      
        
           

        

        
          2

          
            

          

        

        
           

        

      

      2.4. Conversion
        Mechanics.

       

      (a) The
        number of shares of Common Stock to be issued upon each conversion of this
        Debenture shall be determined by dividing that portion of the principal and
        interest and fees to be converted, if any, by the then applicable Fixed
        Conversion Price. 

       

      (b) The
        Fixed
        Conversion Price and number and kind of shares or other securities to be
        issued
        upon conversion shall be subject to adjustment from time to time upon the
        happening of certain events while this conversion right remains outstanding,
        as
        follows:

       

      A. Reclassification,
        etc.
        If
        Borrower at any time shall, by reclassification or otherwise, change the
        Common
        Stock into the same or a different number of securities of any class or classes,
        this Debenture, as to the unpaid Principal Amount and accrued interest thereon,
        shall thereafter be deemed to evidence the right to purchase an adjusted
        number
        of such securities and kind of securities as would have been issuable as
        the
        result of such change with respect to the Common Stock (i) immediately prior
        to
        or (ii) immediately after such reclassification or other change at the sole
        election of the Holder.

       

      B. Stock
        Splits, Combinations and Dividends.
        If the
        shares of Common Stock are subdivided or combined into a greater or smaller
        number of shares of Common Stock, or if a dividend is paid on the Common
        Stock
        or any preferred stock issued by Borrower in shares of Common Stock, the
        Fixed
        Conversion Price shall be proportionately reduced in case of subdivision
        of
        shares or stock dividend or proportionately increased in the case of combination
        of shares, in each such case by the ratio which the total number of shares
        of
        Common Stock outstanding immediately after such event bears to the total
        number
        of shares of Common Stock outstanding immediately prior to such
        event.

       

      2.5. Reservation
        of Shares.
        During
        the period the conversion right exists, Borrower will reserve from its
        authorized and unissued Common Stock a sufficient number of shares to provide
        for the issuance of Common Stock upon the full conversion of this Debenture.
        Borrower represents that upon issuance, such shares will be duly and validly
        issued, fully paid and non-assessable. Borrower agrees that its issuance
        of this
        Debenture shall constitute full authority to its officers, agents, and transfer
        agents who are charged with the duty of executing and issuing stock certificates
        to execute and issue the necessary certificates for shares of Common Stock
        upon
        the conversion of this Debenture.

       

      2.6. Registration
        Rights.
        The
        Holder has been granted registration rights with respect to the shares of
        Common
        Stock issuable upon conversion of this Debenture as more fully set forth
        in a
        Registration Rights Agreement dated as of the date hereof between Borrower
        and
        the Holder.

       

      
        
           

        

        
          3

          
            

          

        

        
           

        

      

      2.7. Issuance
        of New Debenture.
        Upon
        any partial conversion of this Debenture, a new Debenture containing the
        same
        date and provisions of this Debenture shall, at the request of the Holder,
        be
        issued by the Borrower to the Holder for the principal balance of this Debenture
        and interest which shall not have been converted or paid. Subject to the
        provisions of Article III, the Borrower will pay no costs, fees or any other
        consideration to the Holder for the production and issuance of a new
        Debenture.

       

      ARTICLE
        III 

      EVENTS
        OF DEFAULT

       

      The
        occurrence of any of the following events set forth in Sections 3.1 through
        3.9,
        inclusive, shall be an “Event
        of Default”:

       

      3.1. Failure
        to Pay Principal, Interest or other Fees.
        Borrower fails to pay when due any installment of principal, interest or
        other
        fees hereon or on any other promissory note issued pursuant to the Purchase
        Agreement, and such failure shall continue for a period of ten (10) days
        following the date upon which any such payment was due.

       

      3.2. Breach
        of Covenant.
        Borrower breaches any covenant or other term or condition of this Debenture
        in
        any material respect and such breach, if subject to cure, continues for a
        period
        of fifteen (15) days after the occurrence thereof.

       

      3.3. Breach
        of Representations and Warranties.
        Any
        representation or warranty of Borrower made herein, or the Purchase Agreement,
        or in any Ancillary Agreement shall be false or misleading in any material
        respect.

       

      3.4. Stop
        Trade.
        An SEC
        stop trade order or Principal Market trading suspension of the Common Stock
        shall be in effect for 5 consecutive days or 5 days during a period of 10
        consecutive days, excluding in all cases a suspension of all trading on a
        Principal Market, provided that Borrower shall not have been able to cure
        such
        trading suspension within 30 days of the notice thereof or list the Common
        Stock
        on another Principal Market within 60 days of such notice. The “Principal
        Market” for the Common Stock shall include the NASD OTC Bulletin Board, NASDAQ
        SmallCap Market, NASDAQ National Market System, American Stock Exchange,
        or New
        York Stock Exchange (whichever of the foregoing is at the time the principal
        trading exchange or market for the Common Stock), or any securities exchange
        or
        other securities market on which the Common Stock is then being listed or
        traded.

       

      3.5. Receiver
        or Trustee.
        Any
        Borrower or any of its Subsidiaries shall make an assignment for the benefit
        of
        creditors, or apply for or consent to the appointment of a receiver or trustee
        for it or for a substantial part of its property or business; or such a receiver
        or trustee shall otherwise be appointed.

       

      
        
           

        

        
          4

          
            

          

        

        
           

        

      

      3.6. Judgments.
        Any
        money judgment, writ or similar final process shall be entered or filed against
        any Borrower or any of its Subsidiaries or any of their respective property
        or
        other assets for more than $250,000 in the aggregate for Borrower, and shall
        remain unvacated, unbonded or unstayed for a period of thirty (30)
        days.

       

      3.7. Bankruptcy.
        Bankruptcy, insolvency, reorganization or liquidation proceedings or other
        proceedings or relief under any bankruptcy law or any law for the relief
        of
        debtors shall be instituted by or against any Borrower or any of its
        Subsidiaries.

       

      3.8. Default
        Under Other Agreements.
        The
        occurrence of an Event of Default under and as defined in the Purchase Agreement
        or any Ancillary Agreement or any event of default (or similar term) under
        any
        other agreement evidencing indebtedness of at least $500,000.

       

      3.9. Failure
        to Deliver Common Stock or Replacement Debenture.
        Borrower’s failure to timely deliver Common Stock to the Holder pursuant to and
        in the form required by this Debenture and the Purchase Agreement, if such
        failure to timely deliver Common Stock shall not be cured within five (5)
        days.
        If Borrower is required to issue a replacement Debenture to Holder and Borrower
        shall fail to deliver such replacement Debenture within seven (7) Business
        Days.

       

      DEFAULT
        RELATED PROVISIONS

       

      3.10. Default
        Interest Rate.
        Following the occurrence and during the continuance of an Event of Default,
        interest on this Debenture shall automatically be increased by one-half percent
        (0.50%) per month, and all outstanding Obligations, including unpaid interest,
        shall continue to accrue interest from the date of such Event of Default
        at such
        interest rate applicable to such Obligations until such Event of Default
        is
        cured or waived.

       

      3.11. Conversion
        Privileges.
        The
        conversion privileges set forth in Article II shall remain in full force
        and
        effect immediately from the date hereof and until this Debenture is paid
        in
        full.

       

      3.12. Cumulative
        Remedies.
        The
        remedies under this Debenture shall be cumulative.

       

      ARTICLE
        IV 

      DEFAULT
        PAYMENTS

       

      4.1. Default
        Payment.
        If an
        Event of Default occurs and is continuing beyond any applicable grace period,
        the Holder, at its option, may elect, in addition to all rights and remedies
        of
        Holder under the Purchase Agreement and the Ancillary Agreements and all
        obligations of each Borrower under the Purchase Agreement and the Ancillary
        Agreements, to require the Borrowers to make a Default Payment (“Default
        Payment”).
        The
        Default Payment shall be 105% of the outstanding principal amount of the
        Debenture, plus accrued but unpaid interest, all other fees then remaining
        unpaid, and all other amounts payable hereunder. The Default Payment shall
        be
        applied first to any fees due and payable to Holder pursuant to the Debentures
        or the Ancillary Agreements, then to accrued and unpaid interest due on the
        Debentures and then to outstanding principal balance of the
        Debentures.

       

      
        
           

        

        
          5

          
            

          

        

        
           

        

      

      4.2. Default
        Payment Date.
        The
        Default Payment shall be due and payable immediately on the date that the
        Holder
        has exercised its rights pursuant to Section 4.1 (“Default
        Payment Date”).

       

      ARTICLE
        V 

      MISCELLANEOUS

       

      5.1. Failure
        or Indulgence Not Waiver.
        No
        failure or delay on the part of the Holder hereof in the exercise of any
        power,
        right or privilege hereunder shall operate as a waiver thereof, nor shall
        any
        single or partial exercise of any such power, right or privilege preclude
        other
        or further exercise thereof or of any other right, power or privilege. All
        rights and remedies existing hereunder are cumulative to, and not exclusive
        of,
        any rights or remedies otherwise available.

       

      5.2. Notices.
        Any
        notice herein required or permitted to be given shall be in writing and provided
        in accordance with the terms of the Purchase Agreement.

       

      5.3. Amendment
        Provision.
        The
        term “Debenture”
        and all
        reference thereto, as used throughout this instrument, shall mean this
        instrument as originally executed, or if later amended or supplemented, then
        as
        so amended or supplemented, and any successor instrument as it may be amended
        or
        supplemented.

       

      5.4. Assignability.
        This
        Debenture shall be binding upon each Borrower and its successors and assigns,
        and shall inure to the benefit of the Holder and its successors and assigns,
        and
        may be assigned by the Holder in accordance with the requirements of the
        Purchase Agreement.

       

      5.5. Cost
        of Collection.
        If
        default is made in the payment of this Debenture, each Borrower shall jointly
        and severally pay the Holder hereof reasonable costs of collection, including
        reasonable attorneys’ fees.

       

      5.6. Governing
        Law; Consent to Jurisdiction; Waiver of Jury Trial.
        This
        Debenture shall be governed by, and construed in accordance with, the internal
        laws of the State of Nevada without regard to the choice of law principles
        thereof. Each of the parties hereto irrevocably submits to the exclusive
        jurisdiction of the courts of the State of Nevada and the United States District
        Courts situated therein for the purpose of any suit, action, proceeding or
        judgment relating to or arising out of this Agreement and the transactions
        contemplated hereby. Service of process in connection with any such suit,
        action
        or proceeding may be served on each party hereto anywhere in the world by
        the
        same methods as are specified for the giving of notices under this Agreement.
        Each of the parties hereto irrevocably consents to the jurisdiction of any
        such
        court in any such suit, action or proceeding and to the laying of venue in
        such
        court. Each party hereto irrevocably waives any objection to the laying of
        venue
        of any such suit, action or proceeding brought in such courts and irrevocably
        waives any claim that any such suit, action or proceeding brought in any
        such
        court has been brought in an inconvenient forum. EACH
        OF THE PARTIES HERETO WAIVES ANY RIGHT TO REQUEST A TRIAL BY JURY IN ANY
        LITIGATION WITH RESPECT TO THIS AGREEMENT AND REPRESENTS THAT COUNSEL HAS
        BEEN
        CONSULTED SPECIFICALLY AS TO THIS WAIVER.

       

      
        
           

        

        
          6

          
            

          

        

        
           

        

      

      5.7. Maximum
        Payments.
        Nothing
        contained herein shall be deemed to establish or require the payment of a
        rate
        of interest or other charges in excess of the maximum permitted by applicable
        law. In the event that the rate of interest required to be paid or other
        charges
        hereunder exceed the maximum permitted by such law, any payments in excess
        of
        such maximum shall be credited against amounts owed by Borrowers to the Holder
        and thus refunded to the Borrowers

       

      5.8. Construction.
        Each
        party acknowledges that its legal counsel participated in the preparation
        of
        this Debenture and, therefore, stipulates that the rule of construction that
        ambiguities are to be resolved against the drafting party shall not be applied
        in the interpretation of this Debenture to favor any party against the
        other.

       

      [Balance
        of page intentionally left blank; signature page follows.]


      
        
           

        

        
          7

          
            

          

        

        
           

        

      


       

      IN
        WITNESS WHEREOF,
        Borrower has caused this Convertible Debenture to be signed in its name
        effective as of this 28th day of December, 2005.

       

      

        
          	
                   

                	
                   

                	
                   

                
	
                   

                	
                  TRIANGLE
                    PETROLEUM CORPORATION

                
	
                   

                   

                	
                   

                   

                	
                   

                   

                
	 	
                  By:  

                	
                  /s/ MARK
                    GUSTAFSON

                
	
                   

                	
                  Name:
                    Mark Gustafson

                
	
                   

                	
                  Title:
                    President

                


        

        
 

      

      
        
           

        

        
          8

          
            

          

        

        
           

        

      

       

      EXHIBIT
        A

       

      NOTICE
        OF CONVERSION

       

      (To
        be
        executed by the Holder in order to convert all or part of the
        Debenture

      into
        Common Stock)

       

      [Name
        and
        Address of Holder]

      


       

      The
        undersigned hereby converts $_________ of the principal due on [specify
        applicable Date] under the Convertible Debenture issued by Triangle Petroleum
        Corporation (“Borrower”) dated as of ___, 2005 by delivery of shares of Common
        Stock of Borrower on and subject to the conditions set forth in Article II
        of
        such Debenture.

       

      1. Date
        of
        Conversion  _______________________

       

      2. Shares
        To
        Be Delivered: _______________________

       

      ______________________________

       

      By:_______________________________

       

      Name:_____________________________

       

      Title:______________________________