Boninite-like volcanic rocks in the 3.7–3.8 Ga Isua greenstone belt, West Greenland: geochemical evidence for intra-oceanic subduction zone processes in the early Earth

3806Ma Isua rhyolites and dacites affected by low temperature Eoarchaean surficial alteration: Earth's earliest weathering

“…The dominant lithologies within both segments of the belt are similar, comprising amphibolites derived from basaltic, picritic and boninitic protoliths (the latter in the ~ 3700 Ma sequence only), felsic volcanic and sedimentary rocks and chemical sedimentary rocks, particularly chert and banded iron formation (BIF; e.g., Allaart, 1976;Nutman et al, 1984Nutman et al, , 2007Nutman et al, , 2009Nutman et al, , 2010Nutman et al, , 2013Komiya et al, 1999;Polat et al, 2002;Polat and Hofmann 2003, Bolhar et al, 2004, 2005Furnes et al, 2007;Jenner et al, 2009). Plutonic mafic rocks are much less common within the belt, but include some gabbros and ultramafic rocks that were derived from cumulates in layered gabbro intrusions (e.g., Dymek et al, 1988) and from the upper mantle (Friend and Nutman, 2011).…”

2.24 Ga mafic dykes from Taihua Complex, southern Trans-North China Orogen, and their tectonic implications

“…Zirconium is one of the most immobile elements inert to SALM processes (Wood and Blundy, 1997;Hodson, 2002). Thus, correlations between Zr and other elements can be used to evaluate these elements' mobility under SALM (Hodson, 2002;Polat et al, 2002). The linear correlations between Zr and some alkaline-earth elements (e.g., Ba; Fig.…”

Neoarchean siliceous high-Mg basalt (SHMB) from the Taishan granite–greenstone terrane, Eastern North China Craton: Petrogenesis and tectonic implications

“…However, compared with Phanerozoic typical high-Mg andesite that is generally characterized by SiO 2 of 54-65%, MgO of >5%, CaO of <10% and high mg number (>45) (Kelemen, 1995), most of them have higher CaO contents (>10%) and are distinguishable from the former. In contrast, all amphibolites possessing high Si, high Mg and low Ti contents resemble Phanerozoic (e.g., Crawford et al, 1989;Falloon et al, 2007Falloon et al, , 2008 and Archean boninites (e.g., Kerrich et al, 1998;Polat et al, 2002;Smithies, 2002;Smithies et al, 2004aSmithies et al, , 2005Naqvi et al, 2006), according to the IUGS classification (Le Bas, 2000). In the plots of Zr versus Ti and La/Sm versus TiO 2 ( Fig.…”

“…By contrast, other workers Taylor and McLennan (1985) and Sun and McDonough (1989) Phanerozoic and Archean boninites are from the database on the website: http://georoc.mpch-mainz.gwdg.de/georoc/Entry.html. The field of SHMB is from , Seitz and Keays (1997) and Sensarma et al (2002); the island arc basalts and MORB fields are from Polat et al (2002); the Taishan komatiites and pillow basalts are from Polat et al (2006b). disagreed with this interpretation and believed that the parental magma responsible for the PGE mineralization of the Merensky Reef in the Bushveld Complex was boninitic (Hamlyn and Keays, 1986;Hatton and Sharpe, 1989).…”

“…However, increasing evidence has been documented that the volumetrically more minor, metamorphosed volcanic components associated with TTGs could provide significant information on their origin in Archean granite-greenstone belts (e.g., Kerrich et al, 1998;Hollings and Kerrich, 2000;Polat and Kerrich, 2001;Polat et al, 2002;Manikyamba et al, , 2009Manikyamba and Khanna, 2007). Notably, the identification of similar rock assemblages in Archean greenstone belts, which might be analogous to modern successions, has played a critical role in constraining their petrogenetic mechanism and thus of continental growth in the Archean.…”