DAWSON GEOPHYSICAL CO — Director's Dealing 2009

May 28, 2009

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGE)
CIK: 0000799165
Period of Report: 2009-05-27

Reporting Person: Winn Daniel G (Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2009-05-27	Common Stock	S	5250	$5.00	Disposed	29489	Direct

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Stock Option	$4.37	2010-06-06	Common Stock (6078)	6078	Direct
Stock Option	$3.20	2013-10-23	Common Stock (31500)	31500	Direct

Footnotes

F1: Currently exercisable.

F2: Stock options are exercisable as follows: one-third exercisable after 12 months from date of grant; two-thirds exercisable after 24 months from date of grant; and all exercisable after 36 months from date of grant.

F3: Adjusted for the 5% stock dividend paid by the Company to all holders of common stock on May 12, 2009.