VULCAN MINERALS & ENERGY, INC.

                                 PROMISSORY NOTE

800,000.00                                                    HOUSTON, TEXAS
                                                              MARCH 1, 2001


         FOR VALUE  RECEIVED,  Vulcan  Minerals & Energy,  Inc.,  a  corporation
organized  under  the laws of the State of Texas,  having a  principal  place of
business at 650 North Sam Houston Parkway E., Suite 500, Houston,  Texas,  77060
(Vulcan)  hereby  promises to pay to the order of David A.  Rapaport,  as escrow
agent for Generation  Capital  Associates and others ( ( Escrow Agent or Holder)
at 333 Sandy Springs  Circle,  Suite 230,  Atlanta,  GA 30328,  or at such other
place as the Holder may from time to time designate,  the principal sum of Eight
Hundred Thousand ($800,000.00) dollars,  payable in full on or before August 28,
2001  together with interest at the rate of six (6%) percent per annum (based on
a 365 day year) payable monthly in arrears, commencing April 2, 2001.

         This Note is issued under and pursuant to a Letter  Agreement  dated as
of March 1, 2001 (Collateral  Agreement) by and among Vulcan, John N. Ehrman and
Escrow  Agent,  whereby  Escrow Agent is  providing  Bank One,  Texas,  National
Association  (Bank  One) with  collateral  (Collateral)  in the  amount of eight
hundred thousand dollars  ($800,000.00),  as security for a note in the original
principal amount of six million dollars  ($6,000,000.00)  and a Credit Agreement
dated  November 14, 2000, as more fully set forth in the  Collateral  Agreement.
This Note is to evidence  Vulcan's  obligation  to cause Bank One to release the
Collateral  to Holder on or before  August 28, 2001 or to pay an amount equal to
the Collateral to Holder on or before August 28, 2001.

         If Vulcan  shall  have (i)  failed  to cause  Bank One to  release  the
Collateral  to Holder by August 28, 2001,  or otherwise  pay to Holder an amount
equal to the  Collateral  by such date,  or (ii) filed a  voluntary  petition in
bankruptcy  or taken  advantage of any Federal or State  insolvency  law,  (iii)
admitted in writing its  inability  to pay its debts as they  mature,  (iv) been
adjudicated  bankrupt or insolvent,  or (v) had a bankruptcy or other insolvency
petition  filed against it, which shall not have been vacated within thirty (30)
days,  then and in any such event, in addition to all rights and remedies of the
Holder under this Note or any applicable law, all such rights and remedies being
cumulative,  not  exclusive  and  enforceable  alternatively,  successively  and
concurrently,  the Holder may, at his  option,  declare all amounts  owing under
this Note to be due and  payable,  whereupon  the  maturity  of the then  unpaid
principal  balance thereof shall be accelerated and the same,  together with all
interest accrued thereon, shall forthwith become due and payable.

         If any portion of the outstanding  principal or interest due thereon is
not  paid in full  when  due,  then  the  interest  payable  on the  outstanding
principal  amount  shall  thereafter  be at the rate  equal to the lesser of (a)
eighteen (18%) percent per annum (based on a 365 day year) until payment is made
in full; or (b) the highest rate permitted by law.

         Vulcan may prepay this Note in whole or in part at any time.

         In the event of default in the payment of any principal or interest due
under this Note,  Vulcan  agrees to pay all costs and  expenses  incurred by the
Holder hereof in enforcing this Note,  including without limitation,  reasonable
attorney's fee.

         No modification,  rescission, waiver, forbearance, release or amendment
of any provision of this Note shall be made,  except by a written agreement duly
executed  by Vulcan and the  Holder  hereof.  Vulcan  hereby  waives  diligence,
demand, presentment, protest and notice of any kind and assents to extensions of
the  time  of  payment,  release,  surrender  or  substitution  of  security  or
forbearance or other indulgence, without notice.

         This Note shall be governed by and  construed  in  accordance  with the
laws of the State of Georgia,  without regard to the conflicts of law provisions
thereof.  Vulcan hereby irrevocably submits to the jurisdiction of the state and
federal courts  located in Fulton County,  Georgia over any action or proceeding
arising  out  of  any  dispute  between  the  parties  hereto.   Vulcan  further
irrevocably  consents to the service of process in any such action or proceeding
by the mailing,  or sending by overnight courier,  of a copy to Vulcan's address
as set forth above.

         This Note  shall be  subordinated  in  payment  to the Note and  Credit
Agreement  between Vulcan and Bank One dated November 14, 2000;  provided Vulcan
shall be permitted to pay the principal and/or interest  hereunder as long as it
is not in default under the Bank One Note and/or Credit Agreement.

Vulcan Mineral & Energy, Inc.


By: /s/ John N. Ehrman
   --------------------------
   John N. Ehrman, President

March 1, 2001
- -----------------------------
   Date

John N. Ehrman hereby unconditionally  guarantees the full performance of Vulcan
under  the above  Promissory  Note to the same  extent  as if he is the  primary
obligor under such Note.

/s/  John N. Ehrman
   -------------------------
   John N. Ehrman, as an individual

March 1, 2001
- ----------------------------
   Date