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THe period 30 to 36,000 BP was somewhat warmer than most of the last ice age, so the proliferaton of man and leisure time for ritual and art would have been more likely. Then there were a series of reductions in temprature, at least 3 that occurred down to about 20,000 BP. I think I have identified one event as the eruption of Sakura-Jima in Japan which left a 15 mile in diameter Caldera. This occurred about 22,000.

Vesuvius had a plinian type eruption 25,000 BP, but I don't know the size of the caldera it left. If anyone has information on the date and size of other major pleistocene caldera forming events, I would like to know. I know about Toba, Yellowstone, and Long Valley.

Ah, okay, here's more: http://www.dpri.kyoto-u.ac.jp/~kazan/sakurajima_e.html "The acivity of Sakurajima volcano started approximately 13,000 years ago as a post-caldera volcano on the southern rim of Aira Cald[e]ra." http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1984JGR....89.8485A&db_key=PHY&data_type=HTML&format= "About 22,000 years ago a series of large-scale pyroclastic eruptions produced the Aira caldera (20 km¥20 km wide at the northern end of Kagoshima Bay in southern Kyushu. It started with a Plinian pumice erution (Osumi pumice fall, 98 km3) followed by oxidized, fine-grained Tsumaya pyroclastic flow (13 km3), both erupted from a vent located at the present site of Sakuraijima volano, 8 km south of the caldera center. After a very short pause, violent explosive ejection of the basement rock fragments and pumiceous materials occurred at the central vent, gradually changing itself to a huge eruption column rapidly collapsing to form the Ito pyroclastic flow about 300 km3 in volume. The earliest phase produced up to 30-m-thick Kamewarizaka breccia developed along the caldera rim and charged with basement (lithic) fragments up to 2 m across. The breccia is a near-vent variety of the bottom concentration zone of lithics in the Ito deposit. Various textural features and monotonous petrologic character indicate that the main part of the Ito pyroclastic flow was emplaced by a simple, short-lived eruptive mechanism. The Aira-Tn ash, a fine-grained counterpart of the Ito pyroclastic flow, covered a wide area more than 1000 km from the vent. Evacuation of more than 110 km3 of rhyolitic magma produced a funnel-shaped collapse structure with the center of the magma chamber about 10 km deep. Like many other Japanese Quaternary calderas, the Aira caldera is considered to have formed not by a piston cylinder-type subsidence utilizing a ring fracture but by coring and high-angle slumping of the wall rocks into a funnel-shaped central vent. The outline of the caldera was strongly controlled by the faults bounding the volcano-tectonic graben forming Kagoshima Bay." Off the top of my head... Vesuvius is the modern volcano; the older cone with a larger crater is Monte Somma. I guess Vesuvius is Monte Somma's rev- ...nope, I won't say it...

http://www.uwgb.edu/dutchs/EarthSC202Slides/VOLCSLID.HTM

"The high peak is the present summit of Vesuvius (4800 feet). To the right is part of Monte Somma, a ring of ridges that surrounds most of Vesuvius. Long thought to be prehistoric, Monte Somma now seems to be the remains of Vesuvius after the 79 A.D. eruption. Roman paintings of Vesuvius show only a single cone, without a hint of Monte Somma. Also, drawings and paintings of medieval and Renaissance eruptions of Vesuvius, without exception, show the summit of Vesuivius lower than Monte Somma."