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Robert A. DePalma, a 37 year old curator of paleontology at the Palm Beach Museum of Natural History, in Florida, as well as a graduate student at the University of Kansas discovered and started mining a huge fossil deposit found in North Dakota (to be published next week in PNAS) in 2012. The findings include fish with small tektites in their gills (sturgeon and paddlefish), broken and burned vegetation, tektites preserved in amber (fossilized plant resin), some land dinosaurs in a disturbed layer of fine sediments and mud.
Recently the impact events in the Yucatan have been described in a fair amount of detail.
This new yet-to-be-publication (described in stories from the NY Times, The New Yorker magazine, and a UC, Berkeley news release.
It looks like the series of events went like this:
Meteor impact in Yucatan area produces:
Some of the lofted rock material started falling back to Earth (all over the world, heating up on reentry and possibly starting fires) and eventually solidifying into tektites. These were found in the dead animal mud mix and in some cases in the gills of filter feeding fish (paddlefish), indicating they were filtering them out of the water. This is though to have happened with in 45-60 minutes after the impact.
A Tsunami from the impact area (about 3,000 kilometers away) would normally take 10-12 hours to go that far. It could possibly have gotten to the area because there was an extension of the Gulf of Mexico extending north to that area (see map in NY Times pub), but it would have taken too long to match with other events. Maybe this was the cause of the last part, where a big water disturbance then buried the mud/dead animals/tektite assemble under another layer of sediment.
Over that was a top iridium containing layer, a pretty definitive marker of the K-T boundary. Iridium came from vaporized meteor.
Recently the impact events in the Yucatan have been described in a fair amount of detail.
This new yet-to-be-publication (described in stories from the NY Times, The New Yorker magazine, and a UC, Berkeley news release.
It looks like the series of events went like this:
Meteor impact in Yucatan area produces:
- Siezmic waves
- Mega-Tsunami in S. Gulf of Mexico,
- much molten/vaporized rock, launched into space.
Some of the lofted rock material started falling back to Earth (all over the world, heating up on reentry and possibly starting fires) and eventually solidifying into tektites. These were found in the dead animal mud mix and in some cases in the gills of filter feeding fish (paddlefish), indicating they were filtering them out of the water. This is though to have happened with in 45-60 minutes after the impact.
A Tsunami from the impact area (about 3,000 kilometers away) would normally take 10-12 hours to go that far. It could possibly have gotten to the area because there was an extension of the Gulf of Mexico extending north to that area (see map in NY Times pub), but it would have taken too long to match with other events. Maybe this was the cause of the last part, where a big water disturbance then buried the mud/dead animals/tektite assemble under another layer of sediment.
Over that was a top iridium containing layer, a pretty definitive marker of the K-T boundary. Iridium came from vaporized meteor.
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