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| 1 | The Emeishan large igneous province:A synthesis显示文摘The late Permian Emeishan large igneous province(ELIP) covers ~0.3 x 106 km2 of the western margin of the Yangtze Block and Tibetan Plateau with displaced,correlative units in northern Vietnam(Song Da zone).The ELIP is of particular interest because it contains numerous world-class base metal deposits and is contemporaneous with the late Capitanian(~260 Ma) mass extinction.The flood basalts are the signature feature of the ELIP but there are also ultramafic and silicic volcanic rocks and layered maficultramafic and silicic plutonic rocks exposed.The ELIP is divided into three nearly concentric zones(i.e.inner,middle and outer) which correspond to progressively thicker crust from the inner to the outer zone.The eruptive age of the ELIP is constrained by geological,paleomagnetic and geochronological evidence to an interval of <3 Ma.The presence of picritic rocks and thick piles of flood basalts testifies to high temperature thermal regime however there is uncertainty as to whether these magmas were derived from the subcontinental lithospheric mantle or sub-lithospheric mantle(i.e.asthenosphere or mantle plume) sources or both.The range of Sr(I_(Sr) = 0.7040-0.7132),Nd(ε_(Nd)(t) ≈-14 to +8),Pb(^(206)Pb/^(204)Pb_1≈ 17.9-20.6) and Os(γ_(Os) =-5 to +11) isotope values of the ultramafic and mafic rocks does not permit a conclusive answer to ultimate source origin of the primitive rocks but it is clear that some rocks were affected by crustal contamination and the presence of near-depleted isotope compositions suggests that there is a sub-lithospheric mantle component in the system.The silicic rocks are derived by basaltic magmas/rocks through fractional crystallization or partial melting,crustal melting or by interactions between mafic and crustal melts.The formation of the Fe-Ti-V oxide-ore deposits is probably due to a combination of fractional crystallization of Ti-rich basalt and fluxing of C02-rich fluids whereas the Ni-Cu-(PGE) deposits are related to crystallization and crustal contamination of mafic or ultramafic magmas with subsequent segregation of a sulphide-rich portion.The ELIP is considered to be a mantle plume-derived LIP however the primary evidence for such a model is less convincing(e.g.uplift and geochemistry) and is far more complicated than previously suggested but is likely to be derived from a relatively short-lived,plume-like upwelling of mantle-derived magmas.The emplacement of the ELIP may have adversely affected the short-term environmental conditions and contributed to the decline in biota during the late Capitanian. | J.Gregory Shellnutt | 2014 | Geoscience Frontiers2014，5，3： | 50 |
| 2 | Elemental and Sr-Nd iso- tope geochemistry of microgranular enclaves form peralkaline A-type granitic plutons of Eeeishan large igneous province, SW China显示文摘 | Shellnutt J G Jahn B M Dostal J | 2010 | Lithos2010，119，1： | 1 |
| 3 | Permian peralkaline, peraluminous and metaluminous A-type granites in the Panxi district, SW China: their relationship to the Emeishan mantle plume 显示文摘 | Shellnutt J G Zhou M F | 2007 | Chemical Geology2007，243，34： | 1 |
| 4 | Longevity of the Permian Emeishan mantle plume (SW China): 1 Ma, 8 Ma or 18 Ma 显示文摘 | Shellnutt J G Zhou M F Yan D P Wang Y B | 2008 | Geological Magazine2008，145，3： | 1 |
| 5 | Permian peralkaline, peralumi- nou and metaluminous A-type granites in the Panxi dis- trict, SW China: their relationship to the Emeishan man- tle plume显示文摘 | Shellnutt J G Zhou M F | 2007 | Chemical Geology2007，243，： | 1 |
| 6 | The role of Fe-Ti ox- ide crystallization in the formation of A-type granitoids with implications for the Daly gap: An example from the Permian Baima igneous complex, SW China 显示文摘 | Shellnutt JG Zhou MF Zellmer GF | 2009 | Chemical Geology2009，259，： | 1 |
| 7 | Formation of the Late Permian Panzhihua plutonic hypabyssal-volcanic igneous complex: Im- plications for the genesis of Fe-Ti oxide deposits and A-type granites of SW China显示文摘 | Shellnutt J G Jahn B M | 2010 | Earth and Planetary Science Let ters2010，289，： | 1 |
| 8 | Permian peralkaline, peraluminou and metaluminous A-type granites in the Panxi district, SW China: Their relationship to the Emeishan mantle plume显示文摘 | Shellnutt J G Zhou M F | 2007 | Chemical Geology2007，243，： | 1 |
| 9 | Precise age determination of mafic and felsic intrusive rocks from the Permian Emeishan large igneous province (SW China)显示文摘 | J. Gregory Shellnutt Steven W. Denyszyn Roland Mundil | 2011 | Gondwana Research2011，，1： | 1 |
| 10 | Precise age determina- tion of marie and felsie intrusive rocks from the Permian Emeishan large igneous province ( SW China) 显示文摘 | Shellnutt J G Denyszyn S W Mundil R | 2012 | Gondwana Research2012，22，1： | 1 |
| 11 | Precise age determinationof mafic and felsic intrusive rocks from the Permian Emeishan large igneous province (SW China) 显示文摘 | Shellnutt J G Denyszya S W Mundil R | 2012 | Gondwana Research2012，22，： | 1 |
| 12 | Formation of the Late Permian Panzhihua plutonic-hypabyssal-volcanic igneous complex: implications for the genesis of Fe-Ti oxide deposits and A-type granites of SW China显示文摘 | Shellnutt J G Jahn B M | 2010 | Earth and Planetary Science Letters2010，289，34： | 1 |
| 13 | Rifting-related, Permian ferrosyenites inthe Panxi region of the Emeishan large Igneous province, SW Chi-na显示文摘 | Shellnutt J G Zhou M F | 2006 | Geochmica et Cosmochimica Acta2006，70，18： | 1 |
| 14 | Precise age determination of mafic and felsic intrusive rocks from the Permian Emeishan large igneous province (SW China)显示文摘 | Shellnutt J G Denyszyn S W Mundil R | 2012 | Gondwana Research2012，22，1： | 1 |
| 15 | Precise age determinationof mafic and felsic intrusive rocks from the Permian Emeishan largeigneous province (SW China) 显示文摘 | Shellnutt J G Denyszyn S W Mundil R | 2012 | Gondwana Research2012，22，1： | 1 |
| 16 | Chemical and Sr-Nd compositions and ^(40)Ar/^(39)Ar ages of NW-trending dolerite dikes of Burkina Faso: Evidence for a Mesoproterozoic magmatism in the West African Craton显示文摘The Paleoproterozoic basement of the northeastern part of the Leo-Man craton is intruded by generally NW-trending dikes. These regional scale dikes extend over 1000 km in Burkina Faso, Mali and Niger. We present chemical and Sr-Nd isotope compositions, as well as 40 Ar/39 Ar ages of these dikes with the following strikes N98°-N112°, and N114°-N124° in NE Burkina Faso. Field relationships show that the dikes are posterior to all other rock types dated between 2.26 Ga and 2.0 Ga. Chemical data indicate that the dikes are continental flood basalts and composed of low-Ti(TiO2 ≤ 2 wt.%) sub-alkaline basalts and andesites. They exhibit a minor negative Europium anomaly(0.86-0.99) and slightly fractionated REE patterns((La/Yb)_N= 2.5-9.1; Yb_N = 9.5-19.9). The ratios of Th/Ta(1.3-11.4) and Ce/Pb(5.2-58.5)suggest a varying crustal assimilation of the dike magmas during ascent in the continental crust for all studied samples. Calculated P-T conditions indicate that the magma reached temperatures of 1285 ℃(calculated from olivine compositions) and pressures of 6.9 kbar(calculated for pyroxene minerals).Calculated initial 87 Sr/86 Sr(0.70040-0.70260) and ε_(Nd)(t)=+2.1 to-3.5 at 1575 Ma,also point to a crustal contamination with the most primitive samples showing T_(DM) values of 1946 Ma and 2154 Ma. The low values of La/Ba(<0.2) and Nb/La(<1.0), contrast with the low Th/Nb(<0.9), and suggest a lithospheric mantle or subduction-modified mantle as possible source for the dikes. Sr-Nd data, Mg# and NbTa-Zr-Y-Th-Tb-Yb compositions further suggest that the most primitive samples were emplaced in a none orogenic setting and their magmas were subjected to variable crustal contaminations. Literature and the present whole rock 40 Ar/39 Ar age determinations show that the dikes were emplaced during a widespread Mesoproterozoic magmatism between 1.6 Ga and 1.2 Ga, and were affected by a thermal event causing the argon systematics resetting, best constrained by the date of sample KK1(1236 ± 20 Ma,^(40)Ar/^(36)Ar = 294 ±13, MSWD = 2.2). Contemporaneous 1590-1570 Ma extensive magmatism is reported in other crustal blocks in Baltica(Sveconorw-Goth, svecofennian) NW Laurentia(Slave craton, Yukon),and Australia(Gawler craton), and together with the 1575 studied dikes, are related to the breakup of the supercontinent Nuna. | Boukare Tapsoba Ching-Hua Lo Urbain Wenmenga Yoshiyuki Iizuka Sun-Lin Chung Gregory Shellnutt | 2018 | Geoscience Frontiers2018，9，6： | 0 |
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