DAWSON GEOPHYSICAL CO — Director's Dealing 2012

May 9, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGE)
CIK: 0000799165
Period of Report: 2012-05-07

Reporting Person: BARRETT WILLIAM J (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-05-07	Common Stock	S	5437	$10.73	Disposed	1739971	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	161221	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: Reporting Person disclaims beneficial ownership of common stock owned by spouse.

F2: Includes 1,688,122 shares of common stock held in Reporting Persons IRA accounts.

F3: Currently exercisable.

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

F5: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $10.67 to $10.79, inclusive. The reporting person undertakes to provide TGC Industries, Inc., any security holder of TGC, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.