Episodic hydrofracturing and large-scale flushing along deep subduction interfaces: Implications for fluid transfer and carbon recycling (Zagros Orogen, southeastern Iran)

Slow slip in subduction zones: Reconciling deformation fabrics with instrumental observations and laboratory results

“…Finally, it has been shown that at all depths, vein geochemical composition can differ from host composition (e.g., Bachmann et al, 2009aBachmann et al, , 2009bAngiboust et al, 2014bAngiboust et al, , 2015Jaeckel et al, 2018) thus indicating long-range transport of released fluids. This disequilibrium is also witnessed by the identification of warmer incoming fluids in ancient vein systems infiltrating shallower plate interface material (e.g., Vrolijk et al, 1988) and episodic, incremental precipitation of solutes on their way up along veined and hydrofracs pathways (e.g., Taetz et al, 2017;Muñoz-Montecinos et al, 2021a). Stöckhert (2002) and Wassmann and Stöckhert (2013) report extensive evidence for the role of dissolution precipitation creep along the plate interface zone identifying characteristic fabrics.…”

“…In consequence, the same transition to brittle creep would also result from fluid-pressure pulses to quasi-lithostatic pore pressure. This has been suggested to occur from pulsed prograde dehydration reactions or boosts of updip fluid percolation (Brantut et al, 2011; Diener, 2011;Angiboust et al, 2014b;Muñoz-Montecinos et al, 2021a). Slow slip events preceding large subduction earthquakes (Bürgmann, 2018) may also result from rapid fluid pressure changes (see Fig.…”

Subduction earthquake cycles controlled by episodic fluid pressure cycling

“…In that regard, the presence of abundant veins of quartz is a proxy for tensile fractures, which require the pore fluid pressures to locally exceed the magnitude of the minimum compressive stress (Cox, 2010;Sibson, 1998). In particular, these extensional veins are often oriented at high angles compare to the shear fabric, which imply lithostatic pore-fluid pressures and low differential stresses, while the presence of "crack-seal" textures are indicators of pulses of episodic precipitation (Fagereng et al, 2010;Muñoz-Montecinos et al, 2021;Ramsay, 1980).…”

Carbon Mobility and Exchange in a Plate-Interface Subduction Mélange: A Case Study of Meta-Ophiolitic Rocks in Champorcher Valley, Italian Alps

“…On the other hand, significant C mobility in the deep forearc and beneath arcs (> 80 km), can be deduced by high CO 2 output from arc volcanoes (Epstein et al, 2021b;Hilton et al, 2002), by experimental evidence (Caciagli and Manning, 2003), and by the fluid inclusion and mineral record preserved in (ultra) high-P rocks and subarc xenoliths (Frezzotti et al, 2011;Malaspina et al, 2009;McInness and Cameron, 1994;Sapienza et al, 2009;Scambelluri et al, 2016;Stöckhert et al, 2001;Van Roermund et al, 2002). In subduction zones, decarbonation reactions are enhanced by the infiltration of carbonate-bearing rocks by H 2 O-rich fluids (Collins et al, 2015;Cook-Collars et al, 2014;Dolejs and Manning, 2010;Gorman et al, 2006); carbonate dissolution can also be facilitated by this infiltration (Caciagli and Manning, 2003;Dolejs and Manning, 2010;Sanchez-Valle et al, 2003;Frezzotti et al, 2011;Ague and Nicolescu, 2014;Menzel et al, 2020;Muñoz-Montecinos et al, 2021).…”

“…Here, it is important to note that, although several mechanisms of C mobilization have been demonstrated in field studies of metamorphic rocks, the scale at which this mobility occurs tends to be meters to tens of meters and it has proven difficult to extrapolate these observed processes to scales impacting whole-margin C cycling (see the discussion by Epstein et al, 2020). In this respect, still poorly explored is the potential of pressure dissolution processes in subduction-zone rocks in terms of mineral dissolution, mass loss and impact on fluid compositions (Muñoz-Montecinos et al, 2021;Stöckhert, 2002;Van Schrojenstein Lantman et al, 2021).…”