Subduction controls of Hf and Nd isotopes in lavas of the Aleutian island arc

Exhumation of the Panama basement complex and basins: Implications for the closure of the Central American seaway

“…Lu‐Hf isotopic data from the detrital zircons from the middle Eocene strata (300351, 300339), the modern sand from Rio Mamoní (300334) and the three plutonic samples (Parita and Cerro Montuoso batholiths) only yielded positive initial εHf i values (Figure ). These εHf i values lie between the depleted mantle and bulk earth values indicating derivation of the zircons from juvenile magmas typical of oceanic island arcs (similar to the Aleutian and the Mariana arc) [ Tollstrup and Gill , ; Yogodzinski et al ., ].…”

The Hf–Nd isotopic composition of marine sediments

“…Our new determination of the Terrestrial Array is based on present-day Hf and Nd isotopic compositions. For this determination we have included 2140 samples compiled from EarthChem (http:// www.earthchem.org), our previous compilation ; see also EA-2), the data presented in this paper, and recent sediment and volcanic arc data from the literature (van de Flierdt et al, 2007;Carpentier et al, 2008Carpentier et al, , 2009Bayon et al, 2009;Yogodzinski et al, 2010). As was true with the regression through the initial Hf-Nd isotopic compositions, we excluded hydrogenetic and hydrothermal sediments, terrigenous clays, and FeMn crusts and nodules.…”

“…Most sites on the seafloor will acquire a veneer of arc ash or turbidites as they approach the subduction zone, with Hf and Nd isotopes ranging from near MORB values for some arcs (i.e., Marianas), to more continental values for others (i.e., Antilles). Most arcs plot above the Terrestrial Array, due to fractionation of Hf from Nd in the subduction zone (Pearce et al, 1999;Woodhead et al, 2001;Yogodzinski et al, 2010), or ingestion of sediments already above the array (Marini et al, 2005), so mixing with arc detritus is another process that may drive sedimentary compositions above the Terrestrial Array.…”

“…Many arc volcanic rocks plot above the Terrestrial Array (Woodhead et al, 2001), but whether this derives from variable mobility of Hf and Nd in subduction fluids (e.g., , the quantitative retention of Hf in the subducting plate (e.g., (Pearce et al, 1999) or the original sedimentary compositions (Marini et al, 2005;Chauvel et al, 2009;Yogodzinski et al, 2010) is debated. Clearly a primary test of these ideas requires better constraints on the initial composition of sediments delivered to different subduction zones.…”

Distinctly different parental magmas for calc-alkaline plutons and tholeiitic lavas in the central and eastern Aleutian arc

“…Western Aleutian lavas have the highest Nd and lowest Pb isotope ratios of any arc magmas worldwide (Kelemen et al, 2003a(Kelemen et al, , 2003b(Kelemen et al, , 2014Singer et al, 2007;Yogodzinski et al, 2010Yogodzinski et al, , 2015. Both western Aleutian lavas and the plutonic rocks from the central and eastern Aleutians show high εNd and εHf values (Fig.…”