> The evidence is in terms of a layer of ash throughout the
> southern pacific basin that suggests some large volcanic
> activity that could have sunken this huge continent.
Let's see :)
In 1965, cruising off the west coast of Mexico, Joe Worzel detected a reflection with ship's echo sounder from a curious sediment layer. He tracked this layer over several days — over some three hundred miles off the coast and another fifteen hundred miles down the western South American coast. When the sediment boundary appeared to rise close enough to the surface, Worzel took a core. (The sediments were green and had a hydrogen sulfide smell. Worzel jokingly sent a message to Ewing that he had found remnants of lunar green cheese in the Pacific, later reporting that Ewing did not find this humorous). But more important than the green layer, the core also contained a relatively thick layer of what he called white ash. Back at Lamont, Ericson identified the material as ash from a volcanic eruption — one that must have been almost unimaginably enormous to cover the seafloor so extensively.
Not exactly the same as "throughout the southern pacific basin" ;)
The ash layer does extend for about 2,500km x 500 km in the eastern Pacific - and possibly across the Gulf of Mexico and into the Atlantic. It's suggestive of a massive andesitic volcanic eruption, probably within the last 100,000 years. But nothing on the scale necessary to destroy an massive continent.
See: Significance of the Worzell Deep Sea Ash Ewing etal 1959
I'm not sure what further research has been carried out, but we do know an awful lot more about tectonic processes than we did in '59.
Extraordinary claims require at least some evidence.