Successive episodes of reactive liquid flow through a layered intrusion (Unit 9, Rum Eastern Layered Intrusion, Scotland)

Plutonic xenoliths from Martinique, Lesser Antilles: evidence for open system processes and reactive melt flow in island arc crust

“…McBirney and Noyes 1979;Morse 1996), or in an open system involving the input of percolating reactive melts or liquids (Reiners 1998;Coogan et al 2000Coogan et al , 2001Meurer and Claeson 2002;Leuthold et al 2014;Smith 2014;Bouilhol et al 2015;Stuart et al 2016). It has been shown that the products of reactive liquid flow will differ from one produced by simple crystallisation along a liquid line of descent (Reiners 1998) and the addition of low degree melts cause large variations in incompatible trace elements.…”

“…Melt migration through crystal mushes is a common process within crustal storage regions (Leuthold et al 2014;Solano et al 2014). Exposed roots of volcanic arcs, such as the Kohistan palaeo-island arc, Pakistan (Bouilhol et al 2015), Talkeetna, Alaska (Greene et al 2006), Fjordland, New Zealand (Stuart et al 2016) and exposed ultramafic complexes, Alaska (Murray 1972;Irvine 1974) allow for direct observations of the lower crust, and provide an analogue to Martinique plutonic xenoliths.…”

“…The formation and evolution of cumulates and/or crystal mushes has been studied for layered intrusions such as Skaergaard (McBirney and Noyes 1979;McKenzie 2011) and Rum (Bédard et al 1988;Holness 2005;Holness et al 2007; Leuthold et al 2014). The generation of cumulates was traditionally thought to involve crystal settling onto the base of the magma chamber and then subsequent evolution of the interstitial liquid through crystal growth and compaction in a closed system (Wager et al 1960).…”

Experimental petrology constraints on the recycling of mafic cumulate: a focus on Cr-spinel from the Rum Eastern Layered Intrusion, Scotland

“…This process plays a critical role in the construction of large magma chambers via accumulation of successive sills or dykes (Annen et al, 2006;Solano et al, 2012) and is responsible for modification of percolating melt composition and cumulate/crystal mush mineral chemistry, texture and abundance. Interaction between resident cumulate mush and newly injected liquid (reactive liquid flow, or infiltration metasomatism, as defined by Irvine, 1980) modify both the cumulate and the reactive liquid, changing their modal composition, chemistry and texture ( Figure 1) (Leuthold et al, 2014a). O'Hara and Herzberg (2002) stated that despite its importance, the assimilation of mafic crystals/cumulates by mafic melts is frequently underestimated.…”

“…Saint-Blanquat et al, 2011;Leuthold et al, 2012). In open magmatic systems, successive recharge of hot melt rejuvenates and assimilates resident crystal mush and cumulates (Tronnes, 1990;Hildreth and Moorbath, 1988;Bédard and Hébert, 1998;Dungan and Davidson, 2004;Leuthold et al, 2014aLeuthold et al, , 2014b. This process plays a critical role in the construction of large magma chambers via accumulation of successive sills or dykes (Annen et al, 2006;Solano et al, 2012) and is responsible for modification of percolating melt composition and cumulate/crystal mush mineral chemistry, texture and abundance.…”