Natural gas: Older and deeper

A new analysis of a natural gas reservoir in West Texas will be encouraging to exploration companies, as it supports the idea that viable natural gas might be found in unconventional locations, in rocks that are much deeper and older than those of commercially exploited fields. The evidence comes in the form of samples of 'magmatic' CO₂ formed by ancient volcanic activity around 300 million years ago. Previously, most CO₂ present in deep continental deposits had been thought to be have been formed more recently from organic matter or mineral reactions.

300-Myr-old magmatic CO₂ in natural gas reservoirs of the west Texas Permian basin
CHRIS J. BALLENTINE, MARTIN SCHOELL, DENNIS COLEMAN, BRUCE A. CAIN
Nature 409, 327-331 (18 January 2001)
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Geochemistry: New prospects for old gas
BERNARD MARTY
Isotope studies furnish evidence of the source of CO₂ in certain natural-gas reserves, and of the long-term retention of such gas in unexpected environments such as ancient continental crust.
Nature 409, 293-295 (18 January 2001)
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18 January 2001 table of contents