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Several Paleozoic sutures in Southwestern China provide a record of the history of the Paleo-Tethys Ocean, whose birth and final closure are associated with the breakup and assembly of Gondwanaland. Recent studies indicate that there are widespread OIB-type mafic volcanic rocks within these suture zones and intervening terranes. This paper examines the geology and geochemistry of volcanic rocks in...
Within the Panxi rift of the Permian Emeishan large igneous province (ELIP), SW China, a 20 km 2 quartz-bearing fayalite syenitic pluton intrudes the 260 Ma Baima igneous complex (BIC). The fayalite syenite is dated using SHRIMP zircon U–Pb techniques at 252±2.5 Ma. The Panxi fayalite syenite is mainly composed of alkali feldspar, ferroan augite, fayalite, quartz and Fe–Ti oxides and contains...
The Emeishan flood basalts are part of an important large igneous province (LIP) along the western margin of the Yangtze Block, Southwest China. Mafic rocks interlayered with Permian sedimentary rocks in western Guangxi Province, on the southeastern margin of the Yangtze Block, have SHRIMP zircon U–Pb weighted mean ages of 259.6±5.9 Ma and 259.1±4.0 Ma, identical to mafic plutons associated with the...
The Late Middle Permian (∼260 Ma) Emeishan large igneous province in SW China contains two magmatic series, one comprising high-Ti basalts and Fe-rich gabbroic and syenitic intrusions, the other low-Ti basalts and mafic–ultramafic intrusions. The Fe-rich gabbros are spatially and temporally associated with syenites. Each series is associated with a distinctive type of mineralization, the first with...
The late Permian Panzhihua syenitic stock in the Pan-Xi area, SW China, showing the typical association of mantle-derived mafic and alkaline rocks along with silicic units, is genetically related to the upwelling Emeishan plume head. This syenitic intrusion consists mainly of metaluminous syenite, metaluminous to peralkaline quartz syenite with subordinate syenite porphyry and alkali-feldspar granite...
Mafic–ultramafic layered intrusions align along a N–S trending fault zone in the central part of the late Permian Emeishan large igneous province, SW China. We present major and trace element and clinopyroxene Sr, Nd, Pb and O isotopic compositions of three representative mafic–ultramafic layered intrusions, the Panzhihua gabbro intrusion that hosts V–Ti–Fe ores, the Limahe peridotite intrusion that...
The Middle Permian Emeishan large igneous province of SW China has provided the quintessential example of the phenomenon of kilometre-scale pre-eruption domal uplift associated with mantle plume impingement on the base of the lithosphere. One key line of evidence is an interpreted zone of truncation of the platform carbonates belonging to the Maokou Formation that underlies the volcanic pile. Here...
Seismic tomography and deep sounding reveal high-velocity upper mantle (HVUM), high-velocity lower crust (HVLC) and crustal strips beneath the Emeishan Large Igneous Province (ELIP). Such a lithospheric structure is similar to that of typical large igneous provinces (LIPs) elsewhere, such as Ontong Java oceanic plateau and Columbia River LIP (Furumoto et al., 1976; Catchings and Mooney, 1988). This...
The ~260Ma Emeishan Large Igneous Province (ELIP) in southwest China has previously been demonstrated to provide compelling evidence for pre-volcanic crustal doming in support of the mantle plume hypothesis. However this has been questioned by Ukstins-Peate and Bryan (2008) by showing hydrothermal magmatic activity at the Daqiao section. To solve this argument, a detailed characterization of the contact...
The Emeishan large igneous province in SW China comprises a bimodal mafic–silicic suite with the silicic rocks occurring at the uppermost part of the thick lava sequence. The silicic rocks have an age of 257–263Ma, and are thus roughly coeval with the Guadalupian–Loping (G–L) boundary event. Most silicic rocks (trachyte and rhyolite) from the Emeishan province have rather uniform ε Nd values...
There are three types of magmatic sulfide deposits (sulfide-poor PGE deposit, sulfide-rich Ni–Cu deposit and Ni–Cu–PGE deposit) associated with mafic–ultramafic intrusions in the Late-Permian Emeishan large igneous province, SW China. The Limahe deposit represents a sulfide-rich Ni–Cu deposit in the region. Re–Os concentrations and isotopic compositions of the sulfide ores and associated ultramafic...
Microgranular enclaves are common within intermediate to felsic granitic rocks that have I- and S-type affinity however they are rare within alkaline anorogenic granitoids of A-type affinity. The Permian (~260Ma) Emeishan large igneous province (ELIP) of southwest China contains two peralkaline silica saturated A-type granitic plutons that host microgranular enclaves. The enclaves from the Baima pluton...
In the Panxi region of the Late Permian (~260Ma) Emeishan large igneous province (ELIP) there is a bimodal assemblage of mafic and felsic plutonic rocks. Most Emeishan granitic rocks were derived by differentiation of basaltic magmas (i.e. mantle-derived) or by mixing between crustal melts and primary basaltic magmas (i.e. hybrid). The Yingpanliangzi granitic pluton within the city of Panzhihua intrudes...
The Baima mafic–ultramafic layered intrusion of the 260-Ma Emeishan Large Igneous Province (ELIP) hosts the second largest Fe–Ti–(V) oxide deposit in the Panxi region, SW China. It is a ~1600-m-thick layered body intruded by slightly younger syenitic and granitic plutons. The intrusion includes the Lower and Upper Zones. Troctolite and olivine pyroxenite of the Lower Zone contains conformable oxide...
The Panzhihua layered intrusion in the ~260Ma Emeishan large igneous province is composed of melagabbro and Fe–Ti oxide ore bodies in the lower zone (LZ) and the lower part of the middle zone (MZa), and Fe–Ti oxide-poor leucogabbro in the upper part of the middle zone (MZb) and upper zone (UZ). Cumulus apatite grains occur in the ~500- to 600-m-thick MZb, which makes up 25–30% of the ~2-km-thick intrusion...
The age of the Emeishan lavas in SW China remains poorly constrained because the extrusive rocks are (1) thermally overprinted and so represent an open system unsuitable for 40 Ar/ 39 Ar geochronology and (2) in most cases devoid of zircon so that it is impossible for the application of U–Pb geochronology. Existing radiometric age constraints of Emeishan large igneous province are...
The Linghao Formation is composed of interbedded clastic and basaltic rocks in the Napo region of Youjiang Basin, Southwest China. The basalts are geochemically divided into low-Ti and high-Ti groups. Relative to the high-Ti group, the low-Ti group exhibits lower Ti/Y ratios, higher ratios of Th/Nb and Th/La, more significant negative Nb–Ta anomalies and lower ε Nd (t) values (−7.26 to +0...
SHRIMP zircon U-Pb ages, geochemical and Sr-Nd isotopic data are reported for two types of basalts (Type I and Type II) from a Permian volcanic-pyroclastic succession in the Tubagou section, Baoxing area along the southeastern margin of the Songpan-Ganzi terrane (SGT) in the Sichuan province of SW China. Zircons from the uppermost basaltic flows yield crystallization age of 257.3 ± 2.0 Ma, which may...
Claystone beds directly below and above the Emeishan basalts in SW China formed around the Guadalupian-Lopingian (G−L) boundary. Zircons from both levels give U–Pb ages of ~260Ma, and are identical within-error to ages reported for the Emeishan Large Igneous Province (LIP). The claystones lack Nb−Ta anomalies on primitive mantle normalized elemental diagrams; zircons from these claystones have a geochemical...
A previous study suggested that the lowest Xuanwei Formation is derived from weathered clastic materials of silicic composition from the Emeishan large igneous province (ELIP) based on chemostratigraphic correlations (Al2O3/TiO2 ratios) between the two. In this study, we have adopted the model that the Emeishan mantle plume commenced and terminated within a short duration and have investigated the...
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