DAWSON GEOPHYSICAL CO — Director's Dealing 2007

Aug 9, 2007

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGE)
CIK: 0000799165
Period of Report: 2007-08-08

Reporting Person: Winn Daniel G (Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2007-08-08	Common Stock	S	4757	$10.23	Disposed	26748	Direct

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Stock Option	$4.83	2010-06-06	Common Stock (5513)	5513	Direct

Footnotes

F1: Stock options are exercisable as follows: one-third exercisable after twelve months from date of grant; two-thirds exercisable after twenty-four months from date of grant; and all exercisable after thirty-six months from date of grant.

F2: Adjusted for Company's 5% stock dividend paid on April 27, 2007