Caledonian granite radiometric dating tests
Second, since the continental crust develops in at least two stages, we need minerals representative of each stage to fully understand its development, and changes in the processes involved.Craig Storey, Horst Marschall, (Woods Hole) and Florentina Enea High-pressure rocks are notoriously difficult to preserve within the rock record due to metastability.At Portsmouth our group is particularly focussed on the development of Plate Tectonics throughout Earth history.We are addressing fundamental questions with respect to the Earth system such as when did Plate Tectonics begin operating and what changes can be documented in the style and rate of plate movement and subduction through time.
We also work on meteorites and impact craters; in particular methods for dating meteorite formation and their arrival on Earth via accessory minerals and their shocked features.Related to this is the influence of tectonics on ocean circulation and weathering, particularly with its control on CO Penny Lancaster, Craig Storey and Mike Fowler Although the Earth is c.4.6 Ga, the extant record of the continental crust only stretches back to ~4.0 Ga, and is rare until ~3.0 Ga (e.g.Campbell and Allen, 2008), corresponding to the onset of ‘modern’ plate tectonics (e.g. To interrogate the crustal record across this critical period in Earth’s history, we must complement the extant rock record with detrital minerals preserved in younger rocks.Most people are satisfied that some form of Plate Tectonics has been occurring since the Archaean, but how different was it to the modern observable record and when and how did we change from the ancient mode to the modern?
Alongside that we are interested in documenting the rate of continental crustal growth and recycling through time and how any changes in tectonics have influenced the rates of crustal growth and preservation.Whilst medium to high temperature eclogites are present back to the Archaean, suggesting thickened crust, blueschists are only present back to the Neopropterozoic around 800 Ma ago.