(June 9, 2025 at 5:51 pm)SubtleVirtue Wrote:(June 8, 2025 at 10:05 pm)Paleophyte Wrote: By basic reason. Raisin bread can't be older than the raisins withn it and can't be younger than the slices that cur it. The same reasoning works for rocks. Fossils that are between two layers of volcanic material must be younger than the lower layer and older than the upper layer. Date the two layers of volcanic material and you have the age of the fossil bracketed. If the two layers are reasonably close together and your deposition rates aren't aburdly slow, the two ages will be the same, within error.
how do you date a volcanic erruption?
Find the rocks that were erupted. Date the minerals in the rocks. You can get whole-rock ages too, but that's much less reliable and so very 1970s.
