Geology experts tell The Associated Press that Gov. John Kasich's (KAY'-siks) claim that a single energy company could recover $1 trillion worth of oil and gas from Ohio shale is an exorbitant overestimate.

At current oil prices, the figure represents more than four times U.S. oil production last year. Viewed another way, every drop of oil produced in America over the next four years would be worth roughly $800 billion.

Kasich traces the often-repeated figure to a conversation with an energy company CEO. He's never identified the source. Spokesman Rob Nichols declined this week to name the individual, while emphasizing the Republican governor simply relayed what he's been told.

The worth of the deposits is relevant as Kasich seeks a tax increase on big drillers to fund statewide income-tax relief.