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Linking deep CO2 outgassing to cratonic destruction

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National Science Review 2022年第6期9卷 12-22页

作者： Zhao-Xue Wang Sheng-Ao Liu Shuguang Li Di Liu Jingao Liu state key laboratory of geological processes and mineral resources China University of Geosciences

Outgassing of carbon dioxide from the Earth's interior regulates the surface climate through deep *** we examine the role of cratonic destruction in mantle CO2outgassing via collating and presenting new data for Paleozoic kimberlites, Mesozoic basaltic rocks and their mantle xenoliths from the eastern North China Craton（NCC）, which underwent extensive destruction in the early Cretaceous. High Ca/Al and low Ti/Eu and δ26Mg are widely observed in lamprophyres and mantle xenoliths, which demonstrates that the cratonic lithospheric mantle（CLM） was pervasively metasomatized by recycled *** analysis of bubble-bearing melt inclusions shows that redox melting of the C-rich CLM produced carbonated silicate melts with high CO2content. The enormous quantities of CO2in these magmas,together with substantial CO2degassing from the carbonated melt–CLM reaction and crustal heating,indicate that destruction of the eastern NCC resulted in rapid and extensive mantle CO2emission, which partly contributed to the early Cretaceous greenhouse climate episode.

关键词： carbonate metasomatism lithospheric mantle CO2 outgassing deep carbon cycling cratonic destruction North China Craton

Hydration effects on crystal structures and equations of state for silicate minerals in the subducting slabs and mantle transition zone

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Science China Earth Sciences 2016年第4期59卷 707-719页

作者： YE Yu state key laboratory of geological processes and mineral resources China University of Geosciences

There are potentially huge amounts of water stored in Earth's mantle, and the water solubilities in the silicate minerals range from tens to thousands of part per minion(ppm, part per million). Exploring water in the mantle has attracted much attention from the societies of mineralogy and geophysics in recent years. In the subducting slab, serpentine breaks down at high temperature, generating a series of dense hydrous magnesium silicate(DHMS) phases, such as phase A, chondrodite, clinohumite, etc. These phases may serve as carriers of water as hydroxyl into the upper mantle and the mantle transition zone(MTZ). On the other hand, wadsleyite and ringwoodite, polymorphs of olivine, are most the abundant minerals in the MTZ, and able to absorb significant amount of water(up to about 3 wt.% H_2O). Hence, the MTZ becomes a very important layer for water storage in the mantle, and hydration plays important roles in physics and chemistry of the MTZ. In this paper, we will discuss two aspects of hydrous silicate minerals:(1) crystal structures and(2) equations of state(Eo Ss).

关键词： Hydrous silicate mineral Crystal structure Equation of state(Eo S) Mantle transition zone(MTZ) Wadsleyite Ringwoodite

U-Pb Zircon Ages,Geochemical and Sr-Nd-Hf Isotopic Compositions of Granitoids in Western Songpan-Garze Fold Belt:Petrogenesis and Implication for Tectonic Evolution

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Journal of China University of Geosciences 2009年第4期20卷 681-698页

作者：蔡宏明张宏飞徐旺春 state key laboratory of geological processes and mineral resources China University of Geosciences

Granitoids are widespread in the Songpan-Garze （松潘-甘孜） fold belt, western China. These granitoids provide insight into regional tectono-magmatic events, basement nature and tectonic evolution. However, previous studies mainly focused on the eastern Songpan-Garze fold belt. In this article, five granitoid intrusions from the western Songpan-Garze fold belt have been studied. These intrusions are composed of quartz-diorite and granodiorite. Using LA-ICP-MS zircon dating method, the obtained magma crystallization ages are 219±2 Ma for the quartz-diorite and 216±5 Ma for the granodiorite. The ages, combined with regional geological analyses, show that they formed in a post-coilisional tectonic setting. The quartz-diorite and granodiorite display co-linear variation in their chemical compositions. REE compositions for both the quartz-diorite and granodiorite show strongly fractionated patterns with （La/Yb）N=5.02-18.34 and Eu/Eu^＊=0.44-0.89. The quartz-diorites have initial ^87Sr/^86Sr ratios （Isr） of 0.70929-0.71197 and εNd（t） values of -8.6 to -6.1 and the granodiorites have Isr values of 0.70549-0.70997 and εNd（t） values of -8.3 to -4.3. Zircon Hf isotopic data show εHr（t） values of -3.8 to ＋1.6 for the quartz-diorites and -1.2 to ＋3.0 for the granodiorites. Geochemical and Sr-Nd-Hf isotopic compositions indicate that the quartz-diorites and granodiorites have similar petrogenesis. We suggest that the magmas for the quartz-diorites and granodiorites were derived from partial melting of lower crustal mafic source, resulting from amphibole dehydration melting reaction. The probing of the magma source reveals that the western Songpan-Garze fold belt contains an unexposed continental basement, which is similar to the eastern Songpan-Garze fold belt. Geodynamically, it is proposed that a lithospheric delamination model can account for the magma generation for the quartz-diorites and granodiorites in the western Songpan-Garze fold belt.

关键词： granitoid petrogenesis nature ofbasement geodynamics western Songpan-Garzefold belt.

Synchronization Theory and Tungsten-Polymetallic mineralization Distribution in the Qianlishan-Qitianling Area,Southern Hunan

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Journal of Earth Science 2011年第6期22卷 726-736页

作者：李兵 state key laboratory of geological processes and mineral resources China University of Geosciences

Synchronization is an important frontier in contemporary nonlinear *** has been developed and applied widely in the late 20th ***,it has limited applications in geological science,especially in the study of *** ore formation of fluids is a problem of propaga-tion of chemical waves and the generation of their spatiotemporal *** processes and spatiotemporal structures are the essence and core of all geological *** these ideas as guides,giving a new definition for ＂phase＂ in geochemical dynamics,and selecting the concentration data of 10 elements from stream-sediment samples on a 1：50 000 scale,this article applies the syn-chronization theory to the study of the distribution of tungsten-polymetallic mineralization in the Qianlishan（千里山）-Qitianling（骑田岭） area in southern Hunan（湖南） which is one of the most im-portant metallogenetic districts in the Nanling（南岭） *** results show that there are large ore deposits in Shizhuyuan（柿竹园）,Huangshaping（黄沙坪）,Xianghualing（香花岭）,Qitianling,and other areas,which verifies the present distribution of mineral resources in southern ***,this article holds that the spatiotemporal synchronization of chemical waves plays an important role in the science of metallogenesis：it leads to the regional ore zoning centered at Qitianling,confirms that the Yanshan epoch is the chief ore-forming epoch in southern Hunan,and predicts other prospective areas of specific ores.

关键词： Qianlishan-Qitianling area polymetallic deposits synchronization.

Age, Trace Elements and Hf-Isotope Composition of Zircon in Eclogites from the Sulu UHP Belt, East-Central China: Neoproterozoic Intrusion and Subsequent Paleozoic and Early Mesozoic Metamorphism

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Journal of Earth Science 2010年第5期21卷 598-622页

作者：郑建平汤华云赵军红苏玉平余淳梅魏启荣刘庆生吴秀玲 state key laboratory of geological processes and mineral resources China University of Geosciences

The Sulu （苏鲁）-Dabie （大别） orogen in East-Central China formed during the subduction and collision of the Yangtze block with the North China block in Early Mesozoic （240-225 Ma）. Constraints on the nature and derivation of eclogites, which are a significant component of the orogen, can provide useful information about subduction-zone metamorphism and crust-mantle interaction. The U-Pb ages, Hf-isotope ratios and trace-element compositions of zircons in eclogites from the Jiangzhuang （蒋庄）（Jiangsu （江苏） Province） and Rongcheng （荣成）（Shandong （山东） Province） areas indicate that the protoliths of the eclogites derived from ultramafic-mafic complexes or mafic intrusion in the subducted continental lithosphere. The upper intercept age of 852±10 Ma and high tHf （up to 14.7） of the Neoproterozoic zircons in a Jiangzhuang sample indicate that the protoliths represent products of the Neoproterozoic addition of juvenile materials to the older （i.e., Paleo-Mesoproterozoic） continental crust. The zircon ages of eclogites from both localities mainly record the Triassic （230-220 Ma） metamorphism, consistent with the formation of the Sulu orogen in Early Mesozoic. The lower intercept age of 316±4 Ma in a Jiangzhuang sample suggests that thermal activity relating to the paleo- Tethyan in Late Carboniferous also affected the eclogitic protolith.

关键词： age composition zircon eclogite Sulu UHP terrane East-Central China.

Iron isotopic analyses of geological reference materials on MC-ICP-MS with instrumental mass bias corrected by three independent methods

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Acta Geochimica 2018年第5期37卷 691-700页

作者： Chuanwei Zhu Wenning Lu Yongsheng He Shan Ke Hongjie Wu Linan Zhang state key laboratory of geological processes and mineral resources China University of Geosciences

Here we report iron(Fe) isotopic data of three pure Fe solution standards(IRMM-014, GSB Fe, and NIST3126a) and five widely used geological reference materials(RMs) from the United states geological Survey and geological Survey of Japan obtained on a Neptune Plus multi-collector–inductively coupled plasma–mass spectrometer(MC-ICP-MS) in our laboratory over the past 3 years. The instrumental mass bias was corrected by three independent methods: sample-standard bracketing(SSB),Ni doping + SSB, and ^(57)Fe–^(58)Fe double spike + *** reveal that both the Ni doping and double spike methods helped calibrate short-term fluctuations in mass bias. Collectively, almost all measurements of RMs yielded δ^(56)Fe within ± 0.05 of recommended values,provided that each sample was measured four times on MC-ICP-MS. For the first time, new recommended values for NIST SRM3126a are reported(δ^(56)Fe = 0.363 ± 0.006,2SE, 95% CI; and δ^(57)Fe = 0.534 ± 0.010, 2SE).

关键词： Iron isotopic analyses Sample-standardbracketing Double spike Ni doping Referencematerials Precision and accuracy

Review of High-Precision Sr Isotope Analyses of Low-Sr geological Samples

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Journal of Earth Science 2015年第5期26卷 763-774页

作者： Jie Lin Yongsheng Liu Haihong Chen Lian Zhou Zhaochu Hu Shan Gao state key laboratory of geological processes and mineral resources China University of Geosciences

Isotope plays an important role in both tracing and dating in earth science, especially 87Rb-86 Sr system. With the development of earth science, whole-rock analysis can＇t sufficiently meet the requirements for scientific research and the micro-analysis becomes more and more significant. Laser ablation multi-collector inductively-coupled plasma mass-spectrometry（LA-MC-ICP-MS） has been extensively applied in micro-zone analysis due to its low sample-consumption, high accuracy, in situ and low requirements on matrix, but it is still difficult to accurately measure Sr isotope compositions especially for the samples with high Rb/Sr ratios and low Sr contents as it is restricted by severe quality discrimination and various types of mass spectrum interferences. Consequently, thermal ionization mass-spectrometry（TIMS）, as the most accurate and precise method to analyze isotopic ratios, is still the most popular method of analyzing Sr ratios, especially for the samples with low Sr contents. This paper makes a systematic review on the high-precision Sr isotope analyses of low-Sr geological samples, including the micro-sampling technique, ultra-low procedural blank chemical method and TIMS measurement technique. The combination of ultra-low procedural blank and TIMS can be used to perform high-precision micro-analysis of the samples with ng magnitude, which will be undoubtedly an important direction for Rb-Sr geochronology, geochemistry and environmental studies.

关键词： Sr isotope compositions Ultra-low procedural blank TIMS Micro-sampling Sr-specific resin Micro-ion exchange column

Early Cretaceous Post-Collisional Collapse of the Yidun Terrane: Geochronological and Geochemical Constraints from Calc-alkaline to Alkaline Basalts in Xiqiu Area, Southwest China

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Journal of Earth Science 2018年第1期29卷 57-77页

作者： Xutuo Li Danping Yan Liang Qiu state key laboratory of geological processes and mineral resources China University of Geosciences

Several Cretaceous Carlin-like or hydrothermal gold deposits along the Garze-Litang suture zone and Early Cretaceous hydrothermal copper mineralization along the southeastern margin of the Songpan-Garze fold belt were presumed to have a magmatic heat source. However, no actual coeval mag- matic events nearby were discovered. Here, we report zircon SIMS U-Pb age, whole-rock geochemical and Sr-Nd isotopic data of the Xiqiu basalts in the southern end of the Yidun terrane, eastern Tibetan Plateau. New zircon U-Pb ages yield weighted mean ^206pb/^238U age of 117.7±1.6 Ma. The basalts are classified as calc-alkaline to alkaline and have relatively high MgO （4.77 wt.%-10.84 wt.%） and Mg number values （Mg^#=（100×Mg/（Mg＋Fe^2＋））; 45.35-67.28） and positive εNd（t）（t=118 Ma） values （＋1.86 to ＋3.2）, suggesting a OIB-like mantle source that is consistent with the normalized patterns of trace elements and rare earth elements （REEs）. Geochemical data suggest that the primary basaltic magma was generated by low degree partial melting of a heterogeneous source of peridotite-dominated with a minor component of garnet- eclogite or pyroxenite and experienced olivine＋clinopyroxene dominated fractional crystallization. The primary melt compositions calculated from the high MgO samples, in turn, suggest that the Xiqiu basalts were generated at 1.6-2.9 GPa with abnormally hot mantle potential temperatures from 1 465 to 1 540℃. The melting temperatures are similar to the abnormally hot mantle underneath the Colorado Plateau and hotter than the mid-ocean range basalt （MORB） mantle and normal intra-continental mantle. Combined with previous studies, the Cretaceous Xiqiu basalts allow us to reconstruct a tectonic and geodynamic evolution- ary model responsible for the Late Jurassic to Late Cretaceous geological records （magmatism, ore deposits and enhanced exhumation） in the Yidun terrane and southern Songpan-Garze fold belt.

关键词： Early Cretaceous mantle thermal state basalt Yidun terrane tectonic and geodynamic model.

Experimental Determination of Calcite Dissolution Rates and Equilibrium Concentrations in Deionized Water Approaching Calcite Equilibrium

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Journal of Earth Science 2010年第4期21卷 402-411页

作者：龚庆杰邓军王庆飞杨立强佘敏 state key laboratory of geological processes and mineral resources China University of Geosciences

The calcite dissolution rates at 50-250 ℃ and 20 MPa in deionized water with flow rate varying from 0.2 to 5 mL/min were experimentally measured in a continuous flow column pressure vessel reactor. Equilibrium concentration （Ceq） of calcite dissolution in deionized water at 20 MPa was determined using dissolution data according to the iterative method presented by Jeschke and Dreybrodt. The equilibrium concentrations at 50, 100, 150, 200 and 250 ℃ are 1.84×10^-4, 2.23×10^-4, 2.25×10^-4, 2.31×10^-4 and 2.24×10^-4 mol/L, respectively. The Ceq increases first and then decreases with temperature varying from 50 to 250 ℃ at 20 MPa, and the same variation trend occurs at 10 MPa with lower values. The maximum value （or extremum） of Ceq would increase with temperature at constant pressures. The dissolution reaction of calcite in this experiment is approaching the calcite equilibrium, and the reaction order doesn＇t keep a constant at different temperatures, which could imply that a change of the reac- tion mechanism was occurring. The Arrhenius equation shouldn＇t be used to calculate apparent activation energy using rate constant data at different temperatures when the reaction order or reaction mechanism changed.

关键词： calcite dissolution rate equilibrium concentration reaction order.