I know that Aristotle and Pliny wrote about strandings, but could not find exact wording and source. I also wonder if there are other accounts, or maybe even cave drawings or something?
hi! recommend you also x-post to /r/AskAnthropology; maybe /r/Archaeology too
Pliny wrote about one whale stranding itself in Ostia, but I'm not aware of him writing about mass strandings.
By feeding upon these for several days it had quite glutted itself, having made for itself a, channel in the shoaly water. Here, however, the sand was thrown up by the action of the wind to such an extent, that the creature found it quite impossible to turn round; and while in the act of pursuing its prey, it was propelled by the waves towards the shore, so that its back came to be perceived above the level of the water, very much resembling in appearance the keel of a vessel turned bottom upwards.