Press Release Source: TGC Industries, Inc.

TGC Industries Added to Russell 3000® Index

PLANO, Texas, June 25, 2012 /PRNewswire/ -- TGC Industries, Inc. (NASDAQ: TGE) ("TGC") today announced that it has been added to the Russell 3000® Index as of the close of the U.S. markets on June 22, 2012, when Russell Investments ("Russell") reconstituted its comprehensive set of U.S. and global equity indexes. The Russell 3000 Index measures the performance of the largest 3000 U.S. companies, representing approximately 98% of the investable U.S. equity market.

Based on its membership in the Russell 3000 Index, which remains in place for one year, TGC will also automatically be included in the small-cap Russell 2000® Index, as well as the appropriate growth and value style indexes. Russell determines membership for its equity indexes primarily by objective market capitalization rankings and style attributes. The Russell 3000 Index also serves as the U.S. component of the Russell Global® Index. The Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for both passive and active investment strategies.

TGC Industries, Inc., based in Plano, Texas, is a leading provider of seismic data acquisition services with operations throughout the continental United States and Canada. The Company has branch offices in Houston, Midland, Oklahoma City and Calgary.

This press release includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements are based on our current expectations and projections about future events. All statements other than statements of historical fact included in this press release regarding the Company are forward-looking statements. There can be no assurance that those expectations and projections will prove to be correct. Important factors that could cause actual results to differ materially from such expectations and projections are disclosed in the Company’s Securities and Exchange Commission filings, and include, but are not limited to, the dependence upon energy industry spending for seismic services, the unpredictable nature of forecasting weather, the potential for contract delay or cancellation, and the potential for fluctuations in oil and gas prices. We undertake no obligation to publicly update or revise these forward-looking statements, whether as a result of new information, future events or otherwise.

CONTACTS:
Wayne Whitener
Chief Executive Officer
TGC Industries
(972) 881-1099
Jack Lascar / Karen Roan
DRG&L (713) 529-6600

Source: TGC Industries, Inc.