Exhibit 10.1

FIRST AMENDMENT TO INVESTMENT AGREEMENT

This First Amendment to Investment Agreement (this “Amendment”) dated this 3rd
day of September, 2010 is made by and between GeoMet, Inc., a Delaware
corporation (the “Company”), and Sherwood Energy, LLC, a Delaware limited
liability company (the “Investor”).

RECITAL:

WHEREAS, the Company and Investor wish to amend certain provisions of the
Investment Agreement dated June 2, 2010 by and between the Company and Investor
(the “Investment Agreement”) as more fully set forth in this Amendment,
including Sections 7.2 and 7.3 thereof to conform to the requirements of Rule
5640 of The NASDAQ Stock Market LLC; and

WHEREAS, the Company and Investor wish to extend the funding deadline set forth
in Section 2.3(a) to allow additional time for NASDAQ to complete its review of
listing applications submitted by GeoMet.

AGREEMENT:

NOW THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, the undersigned hereby agree as follows:

1. The last sentence of Section 2.3(a) of the Investment Agreement is hereby
amended by restatement in its entirety to read as follows:

“Investor shall have sixteen (16) Business Days after receipt of the
Subscription Notice to fund the purchase of the Backstop Shares.”

2. Section 7.2(a) of the Investment Agreement is hereby amended by restatement
in its entirety to read as follows:

“ (a) Investor Board Representation.

(i) For so long as the Investor 13(d) Group continues to Beneficially Own 20% or
more of the Common Stock of the Company (notwithstanding the definition of
“Beneficially Own,” counting any shares of Preferred Stock on an As-Converted
Basis), Investor shall be entitled to designate two (2) Investor Nominees, and
the parties hereto shall exercise all authority under applicable Law to cause
any slate of directors presented to Stockholders for election to the Board to
include such Investor Nominees.

(ii) For so long as the Investor 13(d) Group continues to Beneficially Own 10%
or more of the Common Stock of the Company (notwithstanding the definition of
“Beneficially Own,” counting any shares of Preferred Stock on an As-Converted
Basis), Investor shall be entitled to designate one (1) Investor Nominee, and

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the parties hereto shall exercise all authority under applicable Law to cause
any slate of directors presented to Stockholders for election to the Board to
include such Investor Nominee.”

3. The introductory paragraph of Section 7.3 of the Investment Agreement is
hereby amended by restatement in its entirety to read as follows:

“ Section 7.3 Procedural Matters. For so long as the Investor 13(d) Group
continues to: (i) Beneficially Own 40% or more of the Backstop Shares it has
acquired pursuant to the Backstop Commitment or otherwise, or (ii) Beneficially
Own 5% or more of the Common Stock of the Company (notwithstanding the
definition of “Beneficially Own,” counting any shares of Preferred Stock on an
As-Converted Basis), the following provisions shall apply:”

4. Ratification. The Investment Agreement, as hereby amended, is ratified and
confirmed in all respects.

5. Governing Law. THIS AMENDMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO ITS RULE OF
CONFLICTS OF LAWS.

6. Counterparts. This Agreement may be signed in any number of counterparts,
each of which shall be an original, with the same effect as if the signatures
were upon the same instrument.

(Remainder of page intentionally left blank)

 

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IN WITNESS WHEREOF, this Amendment is executed by the undersigned on the date
set forth above.

 

GEOMET, INC. By:  

/s/ J. Darby Seré

  J. Darby Seré   Chief Executive Officer SHERWOOD ENERGY, LLC By:  

/s/ Michael McGovern

  Michael McGovern   President

 

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