There was a geophysics done on the Tesoro in 2006 that cost~$38,630 that is recorded. I have also heard that there was also fly overs of the Andes around that time by the U.S. and perhaps even the U.S. Geological Survey as in the excerpt/article below. I had even heard a fly over of the Tesoro was done at that time. I believe the geophysics done of the Tesoro at that time was an air mag, and perhaps even a little more enhanced? We also know that the U.S had, and presumingly still does today, a presence in the Andes, with the U.S. Army having small base camps and small airstrips in the Andes, with the reason being given for these camps, the drug trade.

"During the chaos of the 1990s, when Afghanistan was mired in civil war and later ruled by the Taliban, a small group of Afghan geologists protected the charts by taking them home, and returned them to the Geological Survey’s library only after the American invasion and the ouster of the Taliban in 2001.

Armed with the old Russian charts, the United States Geological Survey began a series of aerial surveys of Afghanistan’s mineral resources in 2006, using advanced gravity and magnetic measuring equipment attached to an old Navy Orion P-3 aircraft that flew over about 70 percent of the country.

The data from those flights was so promising that in 2007, the geologists returned for an even more sophisticated study, using an old British bomber equipped with instruments that offered a three-dimensional profile of mineral deposits below the earth’s surface. It was the most comprehensive geologic survey of Afghanistan ever conducted.

The handful of American geologists who pored over the new data said the results were astonishing but the results gathered dust for two more years, ignored by officials in both the American and Afghan governments. In 2009, a Pentagon task force that had created business development programs in Iraq was transferred to Afghanistan, and came upon the geological data. Until then, no one besides the geologists had bothered to look at the information — and no one had sought to translate the technical data to measure the potential economic value of the mineral deposits.

Soon, the Pentagon business development task force brought in teams of American mining experts to validate the survey’s findings, and then briefed Defense Secretary Robert M. Gates and Mr. Karzai."

http://www.mining.com/1-trillion-motherlode-of-lithium-and-gold-discovered-in-afghanistan/