Principal Life Insurance Company, Raleigh, NC 27612

A member of the Principal Financial Group®

2.6                          Committee:

The duties of the Committee set forth in the Plan shall be satisfied by:

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(a)

Company

(b)

The administrative committee appointed by the Board to serve at the pleasure of the Board.

(c)

Board.

(d)

Other (specify):                                                           .

2.8                          Compensation:

The “Compensation” of a Participant shall mean all of a Participant’s:

XX

(a)

Base salary.

XX

(b)

Service Bonus.

(c)

Performance-Based Compensation earned in a period of 12 months or more.

XX

(d)

Commissions.

XX

(e)

Compensation received as an Independent Contractor reportable on Form 1099.

(f)

Other:

2.9                          Crediting Date:

The Deferred Compensation Account of a Participant shall be credited as follows:

Participant Deferral Credits at the time designated below:

(a)

The last business day of each Plan Year.

(b)

The last business day of each calendar quarter during the Plan Year.

(c)

The last business day of each month during the Plan Year.

(d)

The last business day of each payroll period during the Plan Year.

(e)

Each pay day as reported by the Employer.

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(f)

On any business day as specified by the Employer.

(g)

Other:                                                                           .

Employer Credits at the time designated below:

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(a)

On any business day as specified by the Employer.

(b)

Other:                                                                           .

2.13                   Effective Date:

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(a)

This is a newly-established Plan, and the Effective Date of the Plan is February 1, 2013.

(b)

This is an amendment of a plan named                                            dated                            and governing all contributions to the plan through                                        . The Effective Date of this amended Plan is                       .

2.20                   Normal Retirement Age: The Normal Retirement Age of a Participant shall be:

(a)

Age       .

(b)

The later of age        or the                anniversary of the participation commencement date. The participation commencement date is the first day of the first Plan Year in which the Participant commenced participation in the Plan.

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(c)

Other: The later of Age 65 or 5 Years of Service from Date of Hire

2.23                   Participating Employer(s): As of the Effective Date, the following Participating Employer(s) are parties to the Plan:

Name of Employer

Address

Telephone No.

EIN

TGC Industries, Inc.

101 E. Park Blvd., Suite 955

972-881-1099

74-2095844

Plano, TX 75074

2.26                   Plan: The name of the Plan is

TGC Industries, Inc., Deferred Compensation Plan.

2.28                   Plan Year: The Plan Year shall end each year on the last day of the month of December.

2.30                   Seniority Date: The date on which a Participant has:

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(a)

Attained age 55.

(b)

Completed      Years of Service from First Date of Service.

(c)

Attained age      and completed      Years of Service from First Date of Service.

(d)

Attained an age as elected by the Participant.

(e)

Not applicable — distribution elections for Separation from Service are not based on Seniority Date

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(a)

Base salary:

minimum deferral:                    %

maximum deferral: $                    or 80%

XX

(b)

Service Bonus:

minimum deferral:                    %

maximum deferral: $                    or 100%

(c)

Performance-Based Compensation:

minimum deferral:                    %

maximum deferral: $                    or                     %

XX

(d)

Commissions:

minimum deferral:                     %

maximum deferral: $                    or 100%

XX

(e)

Form 1099 Compensation:

minimum deferral:                     %

maximum deferral: $                    or 100%

(f)

Other:

minimum deferral:                     %

maximum deferral: $                    or                     %

(g)

Participant deferrals not allowed.

4.2                          Employer Credits: Employer Credits will be made in the following manner:

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(a)

Employer Discretionary Credits: The Employer may make discretionary credits to the Deferred Compensation Account of each Active Participant in an amount determined as follows:

XX

(i)

An amount determined each Plan Year by the Employer.

(ii)

Other:                                                                               .

XX

(b)

Other Employer Credits: The Employer may make other credits to the Deferred Compensation Account of each Active Participant in an amount determined as follows:

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(i)

An amount determined each Plan Year by the Employer.

(ii)

Other:                                                                               .

(c)

Employer Credits not allowed.

5.2                          Disability of a Participant:

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(a)

A Participant’s becoming Disabled shall be a Qualifying Distribution Event and the Deferred Compensation Account shall be paid by the Employer as provided in Section 7.1.

(b)

A Participant becoming Disabled shall not be a Qualifying Distribution Event.

5.3                          Death of a Participant: If the Participant dies while in Service, the Employer shall pay a benefit to the Beneficiary in an amount equal to the vested balance in the Deferred Compensation Account of the Participant determined as of the date payments to the Beneficiary commence, plus:

(a)

An amount to be determined by the Committee.

(b)

Other:                                                                                       .

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(c)

No additional benefits.

5.4                          In-Service or Education Distributions: In-Service and Education Accounts are permitted under the Plan:

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(a)

In-Service Accounts are allowed with respect to:

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Participant Deferral Credits only.

Employer Credits only.

Participant Deferral and Employer Credits.

In-service distributions may be made in the following manner:

XX

Single lump sum payment.

Annual installments over a term certain not to exceed      years.

Education Accounts are allowed with respect to:

Participant Deferral Credits only.

Employer Credits only.

Participant Deferral and Employer Credits.

Education Accounts distributions may be made in the following manner:

Single lump sum payment.

Annual installments over a term certain not to exceed      years.

If applicable, amounts not vested at the time payments due under this Section cease will be:

Forfeited

Distributed at Separation from Service if vested at that time

(b)

No In-Service or Education Distributions permitted.

5.5                          Change in Control Event:

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(a)

Participants may elect upon initial enrollment to have accounts distributed upon a Change in Control Event.

(b)

A Change in Control shall not be a Qualifying Distribution Event.

5.6                          Unforeseeable Emergency Event:

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(a)

Participants may apply to have accounts distributed upon an Unforeseeable Emergency event.

(b)

An Unforeseeable Emergency shall not be a Qualifying Distribution Event

6.                                 Vesting:  An Active Participant shall be fully vested in the Employer Credits made to the Deferred Compensation Account upon the first to occur of the following events:

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(a)

Normal Retirement Age.

XX

(b)

Death.

XX

(c)

Disability.

(d)

Change in Control Event

(e)

Other:

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(f)

Satisfaction of the vesting requirement as specified below:

XX

Employer Discretionary Credits:

(i)

Immediate 100% vesting.

(ii)

100% vesting after      Years of Service.

(iii)

100% vesting at age     .

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(iv)

Number of Years
of Service

Vested
Percentage

Less than

1

0

%

1

20

%

2

40

%

3

60

%

4

80

%

5

100

%

6

%

7

%

8

%

9

%

10 or more

%

For this purpose, Years of Service of a Participant shall be calculated from the date designated below:

(1)

First Day of Service.

(2)

Effective Date of Plan Participation.

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(3)

Each Crediting Date. Under this option (3), each Employer Credit shall vest based on the Years of Service of a Participant from the Crediting Date on which each Employer Discretionary Credit is made to his or her Deferred Compensation Account.

XX

Other Employer Credits:

(i)

Immediate 100% vesting.

XX

(ii)

100% vesting after 3 Years of Service.

(iii)

100% vesting at age     .

(iv)

Number of Years
of Service

Vested
Percentage

Less than

1

%

1

%

2

%

3

%

4

%

5

%

6

%

7

%

8

%

9

%

10 or more

%

For this purpose, Years of Service of a Participant shall be calculated from the date designated below:

(1)

First Day of Service.

(2)

Effective Date of Plan Participation.

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(3)

Each Crediting Date. Under this option (3), each Employer Credit shall vest based on the Years of Service of a Participant from the Crediting Date on which each Employer Discretionary Credit is made to his or her Deferred Compensation Account.

(a)

Separation from Service prior to Seniority Date, or Separation from Service if Seniority Date is Not Applicable

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(i)

A lump sum.

(ii)

Annual installments over a term certain as elected by the Participant not to exceed        years.

(iii)

Other:                                                                                             .

(b)

Separation from Service on or After Seniority Date, If Applicable

XX

(i)

A lump sum.

(ii)

Annual installments over a term certain as elected by the Participant not to exceed      years.

XX

(iii)

Other: Annual or quarterly installments over a term certain as elected by the Participant not to exceed 10 years.

(c)

Separation from Service Upon a Change in Control Event

XX

(i)

A lump sum.

(ii)

Annual installments over a term certain as elected by the Participant not to exceed        years.

XX

(iii)

Other: Annual or quarterly installments over a term certain as elected by the Participant not to exceed 10 years.

(d)

Death

XX

(i)

A lump sum.

(ii)

Annual installments over a term certain as elected by the Participant not to exceed        years.

(iii)

Other:                                                                                             .

(e)

Disability

XX

(i)

A lump sum.

(ii)

Annual installments over a term certain as elected by the Participant not to exceed      years.

XX

(iii)

Other: Annual or quarterly installments over a term certain as elected by the Participant not to exceed 10 years.

(iv)

Not applicable.

If applicable, amounts not vested at the time payments due under this Section cease will be:

Forfeited

Distributed at Separation from Service if vested at that time

(f)

Change in Control Event

XX

(i)

A lump sum.

(ii)

Annual installments over a term certain as elected by the Participant not to exceed        years.

XX

(iii)

Other: Annual or quarterly installments over a term certain as elected by the Participant not to exceed 10 years.

(iv)

Not applicable.

If applicable, amounts not vested at the time payments due under this Section cease will be:

Forfeited

Distributed at Separation from Service if vested at that time

7.4

De Minimis Amounts.

(a)

Notwithstanding any payment election made by the Participant, the vested balance in the Deferred Compensation Account of the Participant will be distributed in a single lump sum payment at the time designated under the Plan if at the time of a permitted Qualifying Distribution Event that is either a Separation from Service, death, Disability (if applicable) or Change in Control Event (if applicable) the vested balance does not exceed $                       .  In addition, the Employer may distribute a Participant’s vested balance at any time if the balance does not exceed the limit in Section 402(g)(1)(B) of the Code and results in the termination of the Participant’s entire interest in the Plan

XX

(b)

There shall be no pre-determined de minimis amount under the Plan; however, the Employer may distribute a Participant’s vested balance at any time if the balance does not exceed the limit in Section 402(g)(1)(B) of the Code and results in the termination of the Participant’s entire interest in the Plan.

10.1                   Contractual Liability: Liability for payments under the Plan shall be the responsibility of the:

XX

(a)

Company.

(b)

Employer or Participating Employer who employed the Participant when amounts were deferred.

XX

There are no amendments to the Plan.

TGC Industries, Inc.

Name of Employer

By:

/s/ James K. Brata

Authorized Person

Date:

1/2/13