DAWSON GEOPHYSICAL CO — Director's Dealing 2012

May 4, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGE)
CIK: 0000799165
Period of Report: 2012-05-02

Reporting Person: GARDNER HERBERT M (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-02	Common Stock	S	500	$11.45	Disposed	621644	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	72975	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Nonqualified Stock Option	$3.09	2013-10-22	Common Stock (24320)	24320	Direct
Nonqualified Stock Option	$3.88	2014-12-03	Common Stock (19936)	19936	Direct
Nonqualified Stock Option	$6.32	2016-11-20	Common Stock (16837)	16837	Direct

Footnotes

F1: Includes 268,781 shares held in Reporting Persons IRA accounts.

F2: Reporting Person disclaims beneficial ownership of shares owned by spouse.

F3: Currently exercisable.

F4: The option vests 50% on 11-21-2011 and 50% on 11-21-2012.