Continental flood basalts derived from the hydrous mantle transition zone

Boron isotopes reveal multiple metasomatic events in the mantle beneath the eastern North China Craton

“…In addition, melting experiments on carbonated mid ocean ridge basalts (MORBs) suggest that a majority of subducted oceanic crust geotherms are likely to intersect their solidi at depths of approximately 300-700 km (Thomson et al, 2016). Therefore, dehydration or decarbonation melting of the subducted oceanic slab in or near the MTZ has the ability to refertilize the overlying mantle and reduce its solidus, with the potential to trigger mantle melting at shallower depths (Dasgupta et al, 2007(Dasgupta et al, , 2009Faccenna et al, 2010;Wang et al, 2015). However, the question of how subducted oceanic slabs might affect the heterogeneity of the mantle in an intracontinental setting, or foster its partial melting, is unclear.…”

Petrogenises of Triassic gabbroic and basaltic rocks from Chukotka, NE Russia: Eastern end of the ‘arc–type’ Siberian LIP?

“…Ivanov and Litasov (2014) concluded that the Siberian LIP is formed in a far back-arc region of the Mongolia-Okhotsk subduction system and the influence of subduction in the trace element budget of flood basalts reduces away from subduction zone (e.g., presence of rocks with OIB signature such as meimechite from the northernmost Maymecha-Kotuy region). Recently, on the basis of petrological and geochemical evidence Wang et al (2015) concluded that the generation of arc-like LIPs (such as Karoo, Siberian, and Central Atlantic LIPs; see Fig. 10) ultimately related to fluid/melt derived from subducted slabs.…”

“…Ivanov and Litasov (2014) have shown that the influence of the subduction related deep water cycle on the Siberian LIP on the basis of experimental data and numerical calculations. The thermochemical model by Wang et al (2015) shows that slabtriggered wet-upwelling produces large volumes of melt that may rise from the hydrous mantle transition zone. The above lines of evidence support the hydrous nature of the Siberian LIP.…”

Middle Jurassic MORB-type gabbro, high-Mg diorite, calc-alkaline diorite and granodiorite in the Ando area, central Tibet: Evidence for a slab roll-back of the Bangong-Nujiang Ocean

“…Significant crustal contamination would modify both major-trace elements and radiogenic isotope compositions of basaltic melts (Castillo et al, 1999;X.-C. Wang et al, 2016). Therefore, the relation between major versus trace elements and elements versus radiogenic isotopes can be used to evaluate the effect of crustal contamination on basaltic rocks .…”