Match!

Origin of Late Permian syenite and gabbro from the Panxi rift, SW China: The fractionation process of mafic magma in the inner zone of the Emeishan mantle plume

Published on Nov 15, 2019in Lithos3.913
· DOI :10.1016/J.LITHOS.2019.105160
Zezhong Zhang1
Estimated H-index: 1
(Northwest University (United States)),
Jiangfeng Qin13
Estimated H-index: 13
(Northwest University (United States))
+ 5 AuthorsFangyi Zhang1
Estimated H-index: 1
(Northwest University (United States))
Source
Abstract
Abstract Contemporaneous alkaline and gabbroic intrusions are commonly observed around high-Ti basalt in the inner zone of Emeishan large igneous province (ELIP), the distribution and origin of these igneous rocks are significant to understand the process associated with a head of Emeishan mantle plume activity. In this study, we present detailed petrology, chronology, major and trace element geochemistry, whole rock Sr-Nd isotopes and zircon Hf isotopes for quartz syenite and hornblende gabbro from Miyi area, middle-southern Panxi rift. The Hengshan quartz syenite closely lies to the west of the Hepingcun hornblende gabbro pluton, and both units have identical U-Pb ages (260 Ma). The quartz syenite has high SiO2 (66.74 to 70.63 wt%), Na2O (4.94 to 5.64 wt%) and K2O (4.95 to 5.35 wt%) contents, with significantly negative Eu and Sr anomalies, while the hornblende gabbro displays lower SiO2 (47.80 to 48.85 wt%) and higher MgO (8.09 to 9.06 wt%), TFe2O3 (10.57 to 11.16 wt%) contents with slightly positive Eu and Sr anomalies. The highest eHf(t) values from quartz syenites (QS-1) is up to +10, which is similar to the values of hornblende gabbro (+6.6 to +9.4), indicating the both magmas were predominantly from a mantle-derived component. The negative eNd(t) values (−3.9 to −5.2) and variations in overall eHf(t) values (−5.4 to +1.3) for quartz syenite indicate the rocks had undergone certain extent of contamination by crustal material, combined with the reciprocal normalized trace element patterns, suggesting a common source of both two units. The syenitic and gabbroic units exhibit well-developed correlation of SiO2 with various major oxides, indicating the fractional crystallization plays a major role in magma evolution. We use the MELTS modeling to evaluate the detail fractional crystallization process and the results show that magma composition similar to the quartz syenite can be produced by fractional crystallization of ~4% olivine, ~11% clinopyroxene, ~9% orthopyroxene, ~40% plagioclase and ~8% oxide from a high-Ti basalt magma at ~900 °C. We propose the syenite-gabbro association in Panxi rift coincides with final activity of the Emeishan mantle plume, and the lower part formed the hornblende gabbroic unit in a closed system, the upper part of the intrusion formed the syenitic unit and mixed with the crust material.
  • References (66)
  • Citations (0)
References66
Newest
#1Qiang Jiang (China University of Petroleum)H-Index: 2
#2Nansheng Qiu (China University of Petroleum)H-Index: 4
Last. Chuanqing Zhu (China University of Petroleum)H-Index: 1
view all 3 authors...
Abstract The Emeishan large igneous province (ELIP) is widely considered to be a consequence of a mantle plume. The supporting evidence includes rapid emplacement, voluminous flood basalt eruptions, and high mantle potential temperature estimates. Several studies have suggested that there was surface uplift prior to the eruption of the Emeishan flood basalts. Additionally, the plume's lateral extent is hard to constrain and has been variously estimated to be 800–1400 km in diameter. In this stud...
8 CitationsSource
#1Zhian Bao (Northwest University (United States))H-Index: 8
#2Lu Chen (Northwest University (United States))H-Index: 3
Last. Mengning Dai (Northwest University (United States))H-Index: 5
view all 6 authors...
Controlling the accuracy and precision of sulfur and lead isotopic compositions in natural sulfide minerals requires the use of well-characterized reference materials with matrices similar to those of the unknown samples being analyzed. However, it is often a challenge to prepare natural or synthetic reference materials with homogeneous isotope compositions on a micro-scale. Herein, we report a novel method to synthesize homogeneous sulfide reference materials in the form of nano-particulate pre...
36 CitationsSource
#1Evgenii V. SharkovH-Index: 14
#2Maria M. BoginaH-Index: 4
Last. A. V. ChistyakovH-Index: 6
view all 3 authors...
Large igneous provinces (LIPs) formed by mantle superplume events have irreversibly changed their composition in the geological evolution of the Earth from high-Mg melts (during Archean and early Paleoproterozoic) to Phanerozoic-type geochemically enriched Fe-Ti basalts and picrites at 2.3 Ga. We propose that this upheaval could be related to the change in the source and nature of the mantle superplumes of different generations. The first generation plumes were derived from the depleted mantle, ...
6 CitationsSource
#1Neil Cagney (UCL: University College London)H-Index: 6
#2Fabio Crameri (UCL: University College London)H-Index: 7
Last. John Whitehead (WHOI: Woods Hole Oceanographic Institution)H-Index: 61
view all 7 authors...
Abstract In order to link the geochemical signature of hot spot basalts to Earth's deep interior, it is first necessary to understand how plumes sample different regions of the mantle. Here, we investigate the relative amounts of deep and shallow mantle material that are entrained by an ascending plume and constrain its source region. The plumes are generated in a viscous syrup using an isolated heater for a range of Rayleigh numbers. The velocity fields are measured using stereoscopic Particle-...
6 CitationsSource
#1Yun Chen (CAS: Chinese Academy of Sciences)H-Index: 18
#2Yi-Gang Xu (CAS: Chinese Academy of Sciences)H-Index: 55
Last. Jiwen Teng (CAS: Chinese Academy of Sciences)H-Index: 27
view all 17 authors...
Abstract In an attempt to characterize the subsurface structure that is related to fossil mantle plume activity, a comprehensive geophysical investigation was conducted in the Emeishan Large Igneous Province (ELIP). The nature and geometry of the crust were examined within the scheme of the domal structure of ELIP, which comprises the Inner, Intermediate and Outer zones, which are defined on the basis of the biostratigraphy of pre-volcanic sediments. The bulk crustal properties within the Inner ...
20 CitationsSource
The thermodynamic modeling software MELTS is a powerful tool for investigating crystallization and melting in natural magmatic systems. Rhyolite-MELTS is a recalibration of MELTS that better captures the evolution of silicic magmas in the upper crust. The current interface of rhyolite-MELTS, while flexible, can be somewhat cumbersome for the novice. We present a new interface that uses web services consumed by a VBA backend in Microsoft Excel©. The interface is contained within a macro-enabled w...
62 CitationsSource
#1Yu-Ting Zhong (CAS: Chinese Academy of Sciences)H-Index: 8
#2Bin He (CAS: Chinese Academy of Sciences)H-Index: 30
Last. Yi-Gang Xu (CAS: Chinese Academy of Sciences)H-Index: 55
view all 4 authors...
Abstract 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 mainly from the application of SIMS and LA-ICP-MS U–Pb techniques to zircons from mafic and felsic intrusio...
85 CitationsSource
#1J. Gregory Shellnutt (NTNU: National Taiwan Normal University)H-Index: 18
Abstract The late Permian Emeishan large igneous province (ELIP) covers ∼0.3 × 10 6 km 2 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 ...
109 CitationsSource
#1Roberta L. Rudnick (UMD: University of Maryland, College Park)H-Index: 61
#2S. GaoH-Index: 1
This chapter reviews the present-day composition of the continental crust, the methods employed to derive these estimates, and the implications of the continental crust composition for the formation of the continents, Earth differentiation, and its geochemical inventories. We review the composition of the upper, middle, and lower continental crust. We then examine the bulk crust composition and the implications of this composition for crust generation and modification processes. Finally, we comp...
3,085 CitationsSource
#1J. Gregory Shellnutt (NTNU: National Taiwan Normal University)H-Index: 18
#2Yoshiyuki Iizuka (AS: Academia Sinica)H-Index: 32
Abstract The mantle-derived felsic plutonic rocks of the Emeishan large igneous province consist of peralkaline and metaluminous varieties. The peralkaline rocks appear to be formed by fractional crystallization of mafic magmas whereas the metaluminous plutonic rocks appear to be derived by partial melting of underplated mafic rocks. The metaluminous Woshui pluton is 259.6 ± 0.5 Ma and contains alkali feldspar, clinopyroxene, magnesiohornblende, titanite, magnetite and quartz and was relatively ...
20 CitationsSource
Cited By0
Newest