 Robert M. Holder

Robert M. Holder coauthored a statistical analysis of metamorphic temperature and pressure distributions through geological time. Different apparent thermal gradients record contrasts among burial, heating and cooling environments.^[ref]

The analysis uses the evolving metamorphic record as evidence about tectonic regimes. Preservation, sampling and the interpretation of pressure–temperature estimates enter the comparison, so the record is more informative than a list of isolated oldest examples.