Search results for "Sanukitoid"
showing 2 items of 2 documents
Evolution of a Permian intraoceanic arc–trench system in the Solonker suture zone, Central Asian Orogenic Belt, China and Mongolia
2010
Abstract The identification of a fossil arc–trench system from the ophiolite-decorated Solonker suture zone in the southernmost Central Asian Orogenic Belt (CAOB) enables us to constrain the timing of pre-subduction extension (ca. 299–290 Ma), subduction initiation (ca. 294–280 Ma), ridge–trench collision (ca. 281–273 Ma) and slab break-off (ca. 255–248 Ma) in the Permian. A fraction of proto-arc crust (ca. 45 km long, up to 8 km wide) is preserved as a volcanic–plutonic sequence and is juxtaposed against a wide (ca. 30–80 km) forearc melange. This proto-arc crust comprises two distinct magma series, island arc tholeiite (IAT) and mid-ocean ridge basalt (MORB), both of which have strong sup…
Episodic mantle melting-crustal reworking in the late Neoarchean of the northwestern North China Craton: Zircon ages of magmatic and metamorphic rock…
2012
Abstract The Yinshan Block in the northwestern North China Craton comprises late Neoarchean greenstones, high-grade metamorphic rocks (granulite, charnockite, enderbite and amphibole gneiss), diorites (sanukitoid and Mg-adakite) and granitoids (predominantly trondhjemite-tonalite). A greenstone terrane comprises a volcanic sequence of predominant basalt and dacite, with minor andesite. Zircons from a high-Mg andesite and an andesite have weighted mean 207Pb/206Pb ages of 2533 ± 5 Ma and 2510 ± 7 Ma, respectively, which reflect the timing of two distinct volcanic episodes. These two either predated or postdated a major volcanic episode that formed a basalt-dacite bimodal suite during 2515 ± …