DAWSON GEOPHYSICAL CO — Director's Dealing 2005

May 26, 2005

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TGC INDUSTRIES INC (TGCI)
CIK: 0000799165
Period of Report: 2004-10-05

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2004-10-05	Common Stock	P	613	$2.30	Acquired	384490	Direct
2004-10-11	Common Stock	P	1010	$2.25	Acquired	385500	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	10800	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Warrants (Series A)	$.20	2012-09-10	Common Stock (371000)	371000	Direct
Warrants (Series A2)	$.20	2013-06-12	Common Stock (162329)	162329	Direct
8-1/2% Senior Convertible Preferred Stock	$		Common Stock (375000)	375000	Indirect

Footnotes

F1: Includes 15,700 shares of common stock held in Reporting Person's IRA.

F2: Includes 71,000 additional shares of common stock issuable upon exercise, resulting from application of the warrants' anti-dilution provisions as a result of the PIK dividends paid on the Company's 8-1/2% Senior Preferred Stock.

F3: Includes 12,329 additional shares of common stock issuable upon exercise, resulting from application of the warrants' anti-dilution provisions as a result of the PIK dividends paid on the Company's 8-1/2% Senior Preferred Stock.

F4: The shares of the 8-1/2% Senior Convertible Preferred Stock are convertible into Common Stock on a one-for-one basis.

F5: Immediately convertible.

F6: Adjusted to reflect the correct number of shares owned as reported on Form 5 filed with the SEC on February 8, 2005.

F7: Reporting person disclaims beneficial ownership of shares owned by spouse.

F8: Not applicable.

F9: The 8-1/2% Senior Convertible Preferred Stock is owned by Deed of Trust of William C. Hurtt dated April 10, 1995 FBO William C. Hurtt, Jr. - GST Exempt, of which reporting person is co-trustee and income beneficiary of same.