Yeah, it's far from settled in detail, and for a long time there was a camp that maintained that mantle plumes did not really exist in the normal sense.
However, further imaging work seems to show that 1) they actually do seem to be a classic plume shape in many cases (or, more precisely, have complex shapes compatible with convection), and 2) most do have temperature anomalies associated with them. Some things we thought were plume related may not be, but folks are much more in agreement that they look a lot more like convection-related features.
However, further imaging work seems to show that 1) they actually do seem to be a classic plume shape in many cases (or, more precisely, have complex shapes compatible with convection), and 2) most do have temperature anomalies associated with them. Some things we thought were plume related may not be, but folks are much more in agreement that they look a lot more like convection-related features.
E.g. compare these two papers (which are both basically review papers): https://www.sciencedirect.com/science/article/abs/pii/S00128... https://www.nature.com/articles/s43017-021-00168-6