The role of crustal fertility in the generation of large silicic magmatic systems triggered by intrusion of mantle magma in the deep crust

Zircon ages in granulite facies rocks: decoupling from geochemistry above 850 °C?

“…It was formed by magmatic underplating during the Permian extensional regime between ~ 290 and 280 Ma (e.g. Peressini et al 2007;Sinigoi et al 2011). The main intrusive phase has been dated on zircon by Peressini et al (2007) at 288 ± 4 Ma, with locally earlier magmatic activity at ~ 295 Ma (Sinigoi et al 2011) and 314 ± 5 Ma (Klötzli et al 2014).…”

“…Peressini et al 2007;Sinigoi et al 2011). The main intrusive phase has been dated on zircon by Peressini et al (2007) at 288 ± 4 Ma, with locally earlier magmatic activity at ~ 295 Ma (Sinigoi et al 2011) and 314 ± 5 Ma (Klötzli et al 2014). In the northern part of the Ivrea Zone, the Finero mafic-ultramafic body is characterised by a range of Permian U-Pb zircon dates as well as younger zircon intrusion ages of 232 ± 3 Ma and late fluid-related recrystallisation between ~ 220 and 200 Ma (Zanetti et al 2013;Schaltegger et al 2015;Langone et al 2017).…”

Overlapping Sr–Nd–Hf–O isotopic compositions in Permian mafic enclaves and host granitoids in Alxa Block, NW China: Evidence for crust–mantle interaction and implications for the generation of silicic igneous provinces

“…In a silicic large igneous province (SLIP), the fertility of crust plays a crucial role in governing the generation of large volumes of continental silicic magmas (Bryan, 2007;Bryan et al, 2002). Accordingly, underplated basaltic magmas are commonly considered more as a large reservoir of heat rather than a source of silicic magmas (Bryan, 2007;Bryan et al, 2008;Quick et al, 2009;Sinigoi et al, 2011). Nonetheless, some large volumes of silicic magmas are clearly generated by crystal fractionation of primary mantle-derived magmas accompanied by some assimilation of local wall-rocks (Deering et al, 2011;Rooney and Deering, 2014).…”

The growth of large mafic intrusions: Comparing Niquelândia and Ivrea igneous complexes

“…3.0 g/cm 3 ). Sinigoi et al (2011) interpret U-Pb spot ages on zircons to indicate that the growth of the Ivrea Mafic Complex may have begun with sporadic pulses of mafic magma as early as 295 Ma, whereas the massive growth of the Upper Mafic Complex occurred between 292 ± 4 and 286 ±6 Ma when, at increasing rates of intrusion, mafic magmas invaded more fertile, amphibolite-facies rocks inducing advanced anatexis and inset of incremental growth of granites in the upper crust and volcanic activity.…”

“…Igneous foliation is also described in the Skaergaard Layered Complex, where the deepest gabbros show both foliation and stretching lineation and grade upwards into foliated gabbros without lineation while isotropic rocks are present at the core and at the roof of the complex (Mc Birney and Nicolas, 1997). Moreover, there are increasing evidence that large plutons, either granitic or mafic, may have grown incrementally by episodic injections over millions of years Glazner et al, 2004;Quick et al, 2009) and that cooling beneath the solidus may also have taken further millions of years, especially in deep-seated intrusions (Peressini et al, 2007;Sinigoi et al, 2011). If a large, incompletely solidified body persists in the crust for millions of years, it will accommodate much of the strain in a regional dynamic environment.…”