Re: a "swarm event", the plural is probably more likely. And so far, it's lookin' like the Cs were pretty much spot on.
I'm thinkin' the Earth really did pass through the concentrated drebris from the breakup of the Taurid progenitor back then. Clube & Napier talk about it in their books, The Cosmic Serpent (1982), and again in The Cosmic Winter (1991). Also, D.I. Steel et al. talk about the 'Structure and evolution of the Taurid Complex' https://dl.dropbox.com/u/2268163/StructureOfTauridComplex.pdf
And then in 2010 Bill Napier published a paper Called 'Paleolithic Extinctions and the Taurid Complex' https://dl.dropbox.com/u/2268163/Paleolithic%20extinctions.pdf
That paper pretty much officially ties the Younger Dryas Impact Hypothesis to the Taurids.
Their work describes the progressive breakup of the progenitor of the Taurid Complex. And the evidence that's acumulating so far indicates that during the course of that breakup the Earth must have collided with something like 1.1 billion tons of debris. And the debris consisted of multiple dense clusters of fragments that ranged from dust grains up to stuff that was hundreds of meter wide.
One good example of the kind of cluster were're talking about is the fragments of Comet Linear.
another example is Comet 73P Schwassmann Wachmann 3
I've been studying, and blogging about what I think is the planetary scarring of two of the larger clusters for coming up on four years now. One hit the Laurentide Ice sheet in a region that begins in Northern Minsesota and extents all the way to the Arctic Ocean. The other large cluster hit North Central Mexico.
On my blog I've described the Mexican cluster as having come from the Southeast at a low angle of about 30 degrees. And it devastated an oval shaped region about 200 miles wide that extends from just north of the Mexican Volcanic Ark, up between the Sierra Madre Occidental, and Sierra Madre Oriental moutain ranges, and all the way up into west Texas, and New Mexico.
But where it starts to get interesting is that there is a lake in central Mexico called Lake Cutzeo. That lake is about 150 miles south of the southern end of the impact zone described above. The cluster I described would've passed directly overhead of that location. And the fragments would've been well down into the atmosphere at that point.
In March of this year Isabel Israde-Alcántara et al. published a new paper in PNAS titled 'Evidence from central Mexico supporting the Younger Dryas extraterrestrial impact hypothesis' https://dl.dropbox.com/u/2268163/Mexico%20YD%20Paper.pdf
What they found in the sediments of Lake Cuitzeo is a 10 centimeter thick impact layer containing the kind of impact markers that could only be there if a large, hypervelocity, extra terrestrial object had passed directly overhead. In other words they found compelling evidence that's perfectly consistent with the impact scenario I've described.
What do you think might happen to the surface in the impact zone of a 200 mile wide supercluster of comet fragments, and debris, like the two images shown above, if the cluster is so dense, and fragments are so close together that only those on the leading edge fall into cold atmosphere, and the rest fall into the already superheated impact plumes of those that lead the way, and just crank up the heat, and pressure?
What would you think of the idea of whole mountains melted, ablated, and blown away like butter under a blowtorch? Only to move in the wind like the debris laden froth, and foam, on a giant storm tossed beach? Or still others raised up in an instant as the central uplifts of massive above ground explosions hundreds of times more powerful than the Tunguska blast of 1908? Or of whole mountain ranges melted by temperatures hotter than the surface of the sun, and blown over by supersonic winds that made them dance like the wave in a storm tossed sea?
And what would you think if I told you all of that happened in less than 30 seconds?
I'm thinkin' it'd be A Different Kind of Climate Catastrophe. http://craterhunter.wordpress.com/a-different-kind-of-climate-catastrophe/