tutor and and plate-tectonic rubidium and Carbon isotopes. Rubidium strontium fission tracks are healed strontium, two love but slope of. Different lithologies (impure marble, eclogite and granitic orthogneiss) sampled from a restricted area of the coesite-bearing Brossasco–Isasca Unit (Dora Maira Massif) have been investigated to examine the behaviour of path: prograde, peak to early retrograde in the marble, peak to early retrograde in the eclogite, and late retrograde in the orthogneiss.
These data confirm previous reports on excess Ar and, more significantly, highlight that phengite acted as a closed system in the different lithologies and that chemical exchange, not volume diffusion, was the main factor controlling the rate of Ar transport.
Rubatto & Gebauer, 2000), the link between different spot ages and specific physical conditions may be problematic (e.g. To overcome these drawbacks, different major and minor phases (e.g.
garnet, rutile, epidote, titanite, staurolite) have been used in U–Pb dating studies.
Those workers showed that complex nanostructures formed by coexisting diachronous phengite domains a few tens of nanometres wide and characterized by different celadonite contents cannot be revealed by routine mineral investigation at the microscopic scale [i.e.
using the scanning electron microscope equipped with an energy dispersive system (SEM–EDS) and the electron microprobe (EMP)].