I’ve checked out the reports and the geology of the area, and even touched base with one of the geologists involved. My report for Creation.com concludes they were buried late in Noah’s Flood as the waters were retreating from the land. My report concludes:
The sandstone strata containing the whale fossils are contained within a local area called the Caldera basin. Similar localised basins are found at a number of places along the western coast of Chile. Although the basins are relatively small for Flood deposits, the characteristics of the sediments in these basins and the abundant fossils contained in them indicate that deposition took place during a period of rapid and major coastal subsidence.
Coastal subsidence of this nature is exactly what we would expect in the second part of the Flood when the ocean basins sank, the continents rose and the floodwaters flowed into the ocean. And major coastal subsidence explains the rapid burial of the whales and other creatures because rapid burial was needed soon after death to preserve the fossils. After the ocean basins had mostly subsided and the waters had almost completely drained from the land, the whales and other animals that perished in the catastrophe were buried—toward the end of Noah’s Flood.