DAWSON GEOPHYSICAL CO — Director's Dealing 2004

Dec 15, 2004

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGCI)
CIK: 0000799165
Period of Report: 2004-12-13

Reporting Person: HURTT WILLIAM C JR (Director, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2004-12-13	Common Stock	G	75000	—	Disposed	358398	Direct
2004-12-14	Common Stock	P	40000	$2.74	Acquired	398398	Direct
2004-12-14	Common Stock	P	20000	$2.65	Acquired	418398	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2004-12-15	Warrants (Series C2)	$1	P	5200	Acquired	2007-12-14	Common Stock (5200)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	10800	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Warrants (Series A)	$0.2	2012-09-10	Common Stock (300000)	300000	Direct
Warrants (Series A2)	$0.2	2013-06-11	Common Stock (150000)	150000	Direct
8-1/2% Senior Convertible Preferred Stock	$		Common Stock (375000)	375000	Direct

Footnotes

F1: Reporting person gifted 40,000 shares of TGCI Common Stock to St. George Episcopal Church, Rumson, NJ and 35,000 shares to St. Andrews Episcopal School, Middletown, DE

F2: The shares of the 8-1/2% Senior Convertible Preferred Stock are convertible into Common Stock on a one-for-one basis.

F3: Immediately convertible.

F4: Not applicable.