BUENOS AIRES, Argentina -- The Argentine government's long-sought deal with Chevron to exploit shale oil reserves in Patagonia was strongly criticized Wednesday by Mapuche Indians, human rights activists, environmentalists and leftists who called it a sellout to the U.S. that could drain and pollute the nation's resources.

The $1.5 billion joint venture with Chevron was made public in a brief announcement by the state-owned YPF oil company Tuesday night. President Cristina Fernandez said the deal will promote energy independence for Argentina, but many of her one-time allies warned that it would do the opposite.

"It's an irresponsibility and a lack of consciousness that the national government hands over these resources to Chevron," said Nilo Cayuqueo, who leads a Mapuche community in Neuquen province, where the Vaca Muerta shale oil basin is. "We're talking about money here, nothing else. They don't talk about the environment, or of future generations."

Mapuches say the land belongs to them and contend they weren't consulted about the deal in violation of international treaties covering indigenous peoples. YPF denied that claim Tuesday.

Adolfo Perez Esquivel, an Argentine rights activist awarded the Nobel Peace Prize in 1980, said the deal would hurt the country.

"We Argentines," he said, "are giving our resources to the United States and converting YPF into a highly polluting company that will use this method known as fracking," which requires millions of gallons of fresh water pumped at high pressure to extract oil and natural gas from otherwise unproductive wells deep underground in shale deposits.

Perez Esquivel said he would file suit demanding to see environmental impact studies and try to block the oil development. But he said he had little hope of success since the court system recently overturned an injunction seizing any Chevron profits in Argentina if the company didn't pay a $19 billion damage judgment won by plaintiffs in Ecuador, where the Texaco oil company since bought by Chevron was judged to have contaminated parts of the Amazon.

The deal reached with Chevron is the biggest foreign investment that Argentina has attracted since expropriating YPF from control of the Spanish company Grupo Repsol last year. Repsol is demanding $10 billion in compensation and threatens to sue any oil company that takes over the wells.