Sapphirine-kornerupine rocks from the Reynolds Range, central Australia: constraints on the uplift history of a Proterozoic low pressure terrain

LA-MC-ICPMS Pb–Pb dating of rutile from slowly cooled granulites: Confirmation of the high closure temperature for Pb diffusion in rutile

“…30 Myr over the period 1587-1557 Ma during very slow cooling at ca. 3°C/Myr, in a stable high geothermal regime (Vry and Cartwright, 1994;Williams et al, 1996;Buick et al, 1998;Buick et al, 1999;Rubatto et al, 2001). As discussed later in this paper, the results of the present study support this interpretation and suggest that despite the shallow crustal setting slow cooling at 2-3°C/Myr and could have prevailed for up to 200 Myr.…”

“…The rock is texturally pristine, consisting of cordierite, quartz, and green phlogopite (all to ca.1 mm), with scattered large (to 3 cm) rounded orthopyroxene poikiloblasts. The mineral assemblage is interpreted to have formed at high temperatures near the peak of the granulite facies regional metamorphism, as the associated deformation waned (Vry and Cartwright, 1994).…”

“…(3) The metamorphic P-T-t path, from just prior to and during the peak of granulite-facies metamorphism, through to the subsequent early retrogression at high temperatures ( Fig. 2), has been carefully defined for this sample collection site (Vry and Cartwright, 1994) and subsequently confirmed for other highgrade parts of the Reynolds Range (Buick et al, 1998). The overall cooling rate for the early retrogression at high temperatures is well-defined and slow (ca.…”

“…In order to help resolve the current uncertainty as to the T c of Pb in natural rutile, we have carried out a new empirical determination of the T c using natural rutile from a site for which the timing of granulite-facies metamorphism (ca. 1584 Ma), the high-temperature metamorphic pressure-temperature (P-T) history, and the subsequent slow cooling (3°C/Myr) are all well-constrained (Vry and Cartwright, 1994;Vry et al, 1996;Williams et al, 1996;Buick et al, 1998;Buick et al, 1999;Rubatto et al, 2001). Even though a lower-temperature metamorphic event did affect the area much later during the 400-300 Ma Alice Springs orogeny (Teyssier, 1985;Shaw et al, 1991Shaw et al, , 1992, the initial cooling that followed the metamorphism to high-T and low-P granulite-facies conditions was slow and prolonged, with melt crystallization continuing over ca.…”

Zircon and monazite response to prograde metamorphism in the Reynolds Range, central Australia

“…9 Chondrite normalised REE patterns of zircon cores and overgrowths from granulitic metapelite GP4 and associated leucosome GL4B. Detrital cores have various REE compositions, whereas metamorphic overgrowths show identical patterns indicating that chemical equilibrium between restite and melt was reached during anatexis the rocks reached peak metamorphism and started to cool below the granite solidus (Vry and Cartwright 1994;Buick et al 1998). The data presented here suggest that during this loop partial melts were forming, segregating and crystallising continuously for 30 Ma.…”