14 DAY TRIAL // Without a Bruce Willis to protect, California remained the victim of an Armageddon 35 million years ago.
That's the time when a research team believes that a meteorite as big as three football fields hit the golden state. The impact could have made a giant 3.4 miles (5.5 km) wide craterlike formation buried 4,900 - 5,250 ft (1,490 - 1,600 m) below sea level west of Stockton, California.
The team dated rocks in the formation resembling an impact crater to about 37 to 49 million years ago, but the researchers are keeping on testing rocks from oil exploration wells dug in the zone to reach a firmer conclusion. "It looked interesting because it was circular", said Bennett Spevack, a geologist with ABA Energy Corporation in San Diego.
He first detected the crater while looking at seismic survey data of the Central Valley region. The data clearly displays a circular structure carved out of an ancient sea bed.
The researchers are now looking for deformities in the rocks, like shocked quartz, that emerge only due to the high-shock pressure of an impact. "We've found a few grains that exhibit some features of shock, but there still needs to be other searching and peer reviewing," said Samuel Spevack, Bennett's son, a senior at Grossmont Middle College High School in El Cajon, California. "More rock analysis is required to confirm an impact origin", said David Kring, an expert on impact craters at the Lunar and Planetary Institute in Houston.
"The reason that's important is [that] there are a lot of geologic processes that make circular structures," he added. Bennett Spevack believes that the meteorite could have generated a 1,500-megaton explosion. "This is not big enough to have wiped out the dinosaurs, but I guess it certainly would have made headlines if one this size would hit San Francisco," he said.
California's Central Valley might have been underwater at the time of the collision, which may have provoked a huge tsunami. The possible impact crater, named the Victoria Island structure, is California's second known after the 0.8-mile (1.3-km) Cowell structure to the north but none of these structures is confirmed. "If [the Victoria Island structure] can be proven, it'll be the first one in California," said Bennett Spevack.