[Mike Darancette]

“The fossil-bearing tuffs at this locality lack obvious bedding planes, suggesting that this deposit resulted from a single, catastrophic mass mortality event.”

In addition, from their map, the catastrophe apparently occurred over a vast area. The Yixiang and Jiufotang formations cover half of China, southern Japan, all of Korea, and most of Mongolia.

What a remarkable opportunity to see a snapshot of life as it existed at one short period of time over 100 mya.

The size of the formation is quite large for an single explosive volcanic event there should be evidence in other parts of the world of such an event.

[blam]

"The size of the formation is quite large for an single explosive volcanic event there should be evidence in other parts of the world of such an event."

Pompeii comes to mind.

[capitan_refugio]

I have worked in tuff deposits before, in the area around Bishop, Mono Lake, and Mammoth, CA. The problem with tuffs is that a "single event" in the geologic record might actually have happened over several months or even years. Take the case of a hypothetical ash vent in the Long Valley Caldera (Mammoth area). It might blow ash for a long time, with the deposited ash not showing much of any "bedding," grading, or flow lamination.

These types of deposits are best dated by the material immediately above and below the deposit in question - so you get a range.

[null and void]

What a remarkable opportunity to see a snapshot of life as it existed at one short period of time over 100 mya.

Indeed, a paleo-pompeii...