Geochemical Architecture of the Lower- to Middle-crustal Section of a Paleo-island Arc (Kohistan Complex, Jijal–Kamila Area, Northern Pakistan): Implications for the Evolution of an Oceanic Subduction Zone

Physics and Chemistry of Deep Continental Crust Recycling

“…Next, the liquid line of descent appears to kink in the Mg#-SiO 2 space toward Si enrichment at relatively constant Mg#. This vector requires (Dhuime et al, 2007(Dhuime et al, , 2009Greene et al, 2006;Jagoutz, 2010;Jagoutz et al, 2009;Kelemen et al, 2003;Lee et al, 2006Lee et al, , 2007.…”

“…In order to avoid confusion, we use the term Figure 2 Continental lithospheric sections (a) before removal of pyroxenitic lower crust and (b) after removal and stabilization of continental lithosphere. Preremoval section is synthesized from tilted crustal sections or xenoliths in the Sierra Nevada, Talkeetna, and Kohistan arcs (Dhuime et al, 2007(Dhuime et al, , 2009Ducea, 2002;Saleeby, 1996, 1998b;Greene et al, 2006;Jagoutz, 2010;Jagoutz et al, 2009;Kelemen et al, 2003;Lee et al, 2001aLee et al, , 2006Saleeby et al, 2003). Moho corresponds to a seismic discontinuity, reflecting (a) plagioclase to garnet þ pyroxene phase change or (b) a transition from intermediate/mafic compositions to ultramafic (peridotite).…”

“…(b) Average compositions of high-and low-MgO cumulates from the Sierra Nevada (CA), Kohistan, and Talkeetna paleo-arc systems. Data are from the literature (Dhuime et al, 2007(Dhuime et al, , 2009Greene et al, 2006;Jagoutz et al, 2009;Kelemen et al, 2003;Lee et al, 2006Lee et al, , 2007. Roughly, elements with PM-normalized abundances <1 are compatible and >1 are incompatible with respect to the solid mantle source during peridotite melting.…”

Hyperextension of continental to oceanic-like lithosphere: The record of late gabbros in the shallow subcontinental lithospheric mantle of the westernmost Mediterranean

“…8). These LREE-enriched patterns are characteristic of melts with island arc tholeiitic affinity as those found in volcanic and plutonic rocks in arc and back-arc ophiolites and arc sections (Dhuime et al, 2009;Garrido et al, 2006Garrido et al, , 2007Garrido et al, , 2011Marchesi et al, 2006Marchesi et al, , 2009Proenza et al, 2006).…”

The origin of the Popiel peridotite (Western Sudetes, SW Poland): Metamorphism of the island arc tholeiitic cumulate

“…How ever, the rem nants of pri mary ol iv ine and orthopyroxene grains, as well as the ultra mafic compo si tion, point to a plutonic cu mu late rock, and we fol low the pro posal of Gunia et al (1998), that the rock is sup pos edly an ultra mafic cu mu late formed in an is land arc root. The cumulates formed in vol ca nic arc roots show strongly vari able com po sitions, both in terms of min eral and bulk-rock chem i cal com po sition, which is a func tion of the fractionating magma's start ing com po si tion, its wa ter con tent, and ox y gen fugacity, and of the pres sure and tem per a ture of crystallisation (see the data in e.g., Greene et al, 2006;Dhuime et al, 2009;Chen et al, 2009).…”