Qun-Ke Xia

• Ph D
• Zhejiang University

One of the primary locations of mafic magma production on Earth is the global mid-ocean ridge system. The basalts erupted along ridges probe the upper mantle and can be used to explore the deep carbon cycle. However, mid-ocean ridge basalts (MORBs) degas heavily during magma ascent. Some incompatible-trace-element–depleted and –enriched MORBs avoid...

Plain Language Summary The potential of volcanic CO2 emissions to modulate atmospheric CO2 levels and affect the environment of our planet has been recognized. Some specific volcanic types, such as continental arc volcanism, have been hypothesized to play a dominant role in driving long‐term climate change. Recently, the efficiency of continental a...

Recent research on the water content of large igneous provinces (LIPs) has revealed that water has a significant impact on the formation of LIPs. However, most studies focus on the water content of mafic–ultramafic rocks, while relatively little attention has been paid to the water content of continental flood basalts (CFB), which form the major pa...

Water is critical in the evolution of the mantle due to its strong influence on the physicochemical properties of mantle rocks. Mid‐ocean ridge basalts (MORBs) are commonly used to study the compositional characteristics of the convecting upper mantle. However, there remains abundant samples in the global MORB data sets without direct measurements...

The transition zone is dominated by polymorphs of olivine, wadsleyite, and ringwoodite, which are to date considered the main water carriers in the Earth’s mantle. Despite considerable studies on water solubility and its impact on physical properties of the two minerals, knowledge of their hydrogen defects and framework behavior at high temperature...

高温高压条件下的热力学平衡是开展地幔地球化学研究的重要基础。目前，对地幔条件下矿物和熔体的热力学平衡的认识还存在不足，即地幔地球化学的实验和天然样品数据（压强、温度和成分等）构成的高维度矩阵中离散点之间的关系还未被充分厘清。机器学习是挖掘数据的有效工具，通过回归、分类等算法，可以为地幔条件下的热力学平衡提供新认识。已开展的实例研究包括温压计、熔体中元素的溶解度、矿物的三价铁含量、判断地幔捕掳体是否发生交代作用、判断样品是否发生氢扩散作用，等等。本研究方向的发展还需要机器学习方法使用的普及、基础数据库正确率的提升、数据质量的提高、以及算法的改进。

大数据与人工智能为矿物学岩石学地球化学研究提供了新途径。 近年来,出现了一批有国际显示度的,针对地球内部物质组成的数据驱动型研究成果。 为促进相关问题的讨论和知识的传播,本专题将以已取得的成果为实例,展开阐述大数据与人工智能的基本原理及其给地球内部物质组成带来的新认识。 本专题由八篇论文组成,分别从图像处理,地球化学表格数据的机器学习研究,热力学统计模拟,以及原子尺度模拟等方面出发,介绍每种方法涉及的基本原理及其在矿物学岩石学地球化学研究中的应用。本专题作者大多是海内外华人青年学者,是本领域使用大数据和人工智能手段的有生力量。我们相信,新时代的年轻人会在前人探索的基础上,在该方向继续开拓创新,在新一轮的全球竞争中占据学术高地。

Abstract The disruption of the mantle roots of cratons is common after cratonization. Craton destruction, which is characterized by severe lithospheric thinning, extensive thrust and extensional deformation, basin filling, and intense thermal activities, is relatively rare and is generally attributed to intensely reduced viscosity contrasts between...

Clinopyroxene ferric iron content is an important consideration for garnet-clinopyroxene geother-mometry and estimations of water storage in the Earth's interior but remains difficult and expensive to measure. Here, we develop seven classic algorithms and machine learning methods to estimate Fe 3+ /ΣFe in clinopyroxene using major element data from...

Partial melting in the continental crust may play a critical role on the behavior of continents during collision. However, the occurrence of partial melt in orogenic continental crust is not well understood. Since the temperature of the orogen is controlled by the thermal properties of constituent rocks, we measured the thermal conductivity and dif...

The Early Cretaceous Jehol Biota evolution has remarkable spatiotemporal correlation with the destruction of the North China craton though the coupling mechanism remains enigmatic. The craton destruction was accompanied by intense magmatic activity and the released volatiles and nutrients might have had climatic and environmental impacts on the bio...

Li-rich micas are crucial in the exploration for and exploitation of Li resources. The determination of Li in mica using classical bulk chemical methods or in situ microanalytical techniques is expensive and time-consuming and has stringent requirements for the quality of micas and reference materials. Although simple linear and nonlinear empirical...

Nitrogen recycling between Earth's interior and exterior determines the evolution of the atmosphere and habitability of the planet. However, the contribution of subduction to the deep nitrogen recycling is still highly debated. Ammonium‐bearing silicate minerals are the main nitrogen carriers in subduction zones. Nitrogen retention in subduction‐zo...

Knowledge of volatile cycling is vital to understanding the evolution of the planet and the life it supports. Although it has been gradually accepted that the mantle is a vast storehouse of H2O and other volatiles, the impact of coexisting volatiles on the thermal stabilities of OH and the lattice of the host mineral is still poorly understood. Phl...

Initiation of large igneous provinces (LIPs) and temporal and spatial variations in their chemical compositions provide unique opportunities to understand mantle dynamics. It has been recently revealed that water‐rich reservoirs in the mantle sources have played a significant role in the production of LIPs. However, the dominant causes for the chem...

Spectral features of hydrogen defects in natural mantle minerals derive from physico-chemical conditions of the lithosphere. Although hydrogen defects in synthetic orthopyroxene have been well investigated, their complex spectral features in natural orthopyroxenes are still difficult to decipher. To clarify this issue, it is indispensable to reveal...

Previous studies showed that metal preconcentration in fluids and/or magma is critical to the formation of gold deposit in arcs and is closely related to the segregation of sulfide phases. However, the depth range and the magnitude of and associated mechanism by which the deep crust controls the metal preconcentration of arc mineralization remain e...

Mantle plume-generated basalts have long been utilized to assess the large-scale heterogeneity of the deep mantle. Their chemical and isotopic enrichment has been thought to result from the incorporation of recycled sediments or oceanic crust in their sources. Variable extents of dehydration or rehydration of recycled materials during subduction ca...

Plain Language Summary The H2O content of clinopyroxene (cpx) phenocrysts in basaltic magma has become an important way to evaluate the H2O content of Earth's mantle. However, it remains controversial whether samples collected in the field can truly reflect mantle water contents, particularly given the propensity for hydrogen to diffuse out of the...

Hydrogen isotopes have been widely used as powerful tracers to understand the origin of terrestrial water and the water circulation between the surface and the deep interior of the Earth. However, further quantitative understanding is hindered due to a lack of observations about the changes in D/H ratios of a slab during subduction. Here, we report...

Li-rich micas are crucial in the exploration for and exploitation of Li resources. The determination of Li in mica using classical bulk chemical methods or in situ microanalytical techniques is expensive and time-consuming and has stringent requirements for the quality of micas and reference materials. Although simple linear and nonlinear empirical...

Magmatic liquids, including silicate and carbonate melts, are principal agents of mass and heat transfer in Earth and terrestrial planets, and they play a crucial role in various geodynamic processes and Earth's evolution. Electrical conductivity data of these melts elucidate the cause of electrical anomalies in Earth's interior and shed light on t...

The incorporation of water in nominally anhydrous minerals plays a crucial role in many geodynamic processes and evolution of the Earth and affects the physical and chemical properties of the main constituents of the Earth's mantle. Technological advances now allow the transport properties of minerals to be precisely measured under extreme conditio...

Dehydration in hydrous phases of the downgoing slab controls water release processes in subduction zones. Interplay between volatiles in hydrous minerals has complicated the previous knowledge of their dehydration. Phengite is an essential mineral carrying both hydrogen and nitrogen to the deep Earth. To further understand the link between nitrogen...

Layered intrusions host some of the world’s most important ore deposits, yet their global distribution, age, and petrogenesis remain poorly known. Here we provide an update on our current understanding and highlight some key outstanding research questions, notably on the potential importance of reactive flow. We present some preliminary data on wat...

It has long been known that hydrogen impurities can be incorporated in the structure of nominally anhydrous minerals (NAMs) and substantially influence their physical properties. One of the geologically most prominent NAMs is feldspar. The hydrogen concentration in NAMs is usually expressed in parts per million of water by weight (ppm H2O wt.) In t...

Because an oceanic plate colliding with a continental plate will usually be subducted and recycled into the deep mantle, a fossil oceanic plate after the closure of an ancient ocean has rarely been imaged in the subcontinental lithospheric mantle. This has led to a long-standing debate about the fate of subducted ocean plates. The problem can be ad...

It has been suggested that the longevity of cratons is related in part to the low water content of their deep mantle roots, which leads to a much higher viscosity than that of the underlying asthenosphere. Consequently, removal of cratonic roots is thought to be closely related to hydration of the lowermost lithospheric mantle. The North China Crat...

Global correlations of mid-ocean-ridges basalt chemistry, axial depth and crustal thickness have been ascribed to mantle temperature variations affecting degree of melting. However, mantle H2O content and elemental composition may also play a role. How H2O is distributed in the oceanic upper mantle remains poorly constrained. We tackled this proble...

A discontinuity in the seismic velocity associated with the lithosphere-asthenosphere interface, known as the Gutenberg discontinuity, is enigmatic in its origin. While partial mantle melts are frequently suggested to explain this discontinuity, it is not well known which factors critically regulate the melt production. Here, we report geochemical...

The Pacific plate since the Mesozoic is subducting into the mantle beneath the eastern Asia, and the involved recycled crustal material has greatly affected the mantle geochemistry. However, the initial timing of the subduction remains controversial, partly due to the insufficient understanding of the geochemical evolution of the Mesozoic mantle. T...

A large number of seismic topographical studies have shown the westward subducted Pacific plate in the mantle transition zone beneath the eastern Asian, forming the so-called Big Mantle Wedge (BMW). Several recent studies also suggest that such BMW has been initiated from the early Cretaceous. Some previous investigations on the water contents from...

Anhydrous, medium/coarse-grained spinel bearing mantle xenoliths from the Subei Basin, Eastern China have mineral arrangements that reflect low energy geometry. Because of clinopyroxene modal contents, they are grouped into cpx-rich lherzolites (cpx ≥ 14percentage), lherzolites (8 < cpx < 14%), cpx-poor lherzolites (6 < cpx ≤ 8%) and harzburgites (...

Large igneous provinces (LIPs) are generally considered to be related to mantle plumes and to have a great importance to the supercontinent break-up events, climate change and biological evolution over Earth's history. The high melt production rates of LIPs can be achieved under rigorous melting conditions: an abnormally high temperature, substanti...

Magmatism at some intraplate volcanoes and large igneous provinces (LIPs) in continental areas may originate from hydrous mantle upwelling (i.e. a plume) from the mantle transition zone (MTZ) at 410–660 km depths in the Earth’s deep interior. However, the ultimate origin of the magmatism, i.e. why mantle plumes could have been generated at the MTZ,...

The structural hydroxyl content of the nominally anhydrous minerals (olivine and pyroxenes) in the upper mantle is among the important attributes that influence the physical and chemical features of the upper mantle. In this study, we provide detailed Fourier-transform infrared (FTIR) data on 63 petrographically and geochemically well-defined upper...

Water incorporated as hydrogenated defects in mantle minerals can influence physical properties of the mantle. Knowledge of hydrogen defects at high temperatures (T) is fundamental to understand and quantify their influence on mantle physical properties. Clinopyroxene contributes significantly to the upper mantle water budget. Here, we investigate...

Water can be incorporated as defects and influence physical properties of feldspars. Extensive works have investigated the temperature-induced displacive phase transition in alkali feldspar and found that the transition temperature is dependent on both the orthoclase composition and degree of Al-Si order. However, there has been so far no report co...

Mantle xenoliths exhumed from beneath the South Island of New Zealand offer an opportunity to investigate the role of lithospheric mantle water in influencing deep lithosphere deformation and formation of the narrow Southern Alps mountain range during orogeny along the Australia–Pacific plate boundary. Fourier transform infrared spectrometry (FTIR)...

Appreciated attempts have been devoted to use a simple unpolarized infrared analysis on unoriented anisotropic crystals of nominally anhydrous minerals to determine the content of H-species, rather than using the more demanding polarized techniques which determine by experimental work of both polarized and unpolarized analyses. In this study, we pr...

Feldspars are abundant in the crust of the Earth. Multiple hydrogen species such as OH, H2O and NH4⁺ can occur in the structure of feldspars. Hydrogen species play a critical role in influencing some properties of the host feldspars and the crust, including mechanical strength, electrical property of the crust, and evolution of the crustal fluids....

Mantle pyroxenite xenoliths were collected from Hannuoba, East China, and investigated for their H2O content and trace element contents, with particular regard to the H2O/Ce ratio. The pyroxenites were divided into three groups: Cr-pyroxenites, Al-pyroxenites, and garnet pyroxenites. The H2O contents and H2O/Ce ratios of the pyroxenites in this stu...

The genesis of large igneous provinces (LIP) is controlled by multiple factors including anomalous mantle temperatures, the presence of fusible fertile components and volatiles in the mantle source, and the extent of decompression. The lack of a comprehensive examination of all these factors in one specific LIP makes the mantle plume model debatabl...

Whole-rock and mineral geochemical data are used to place new constraints on the petrogenesis and tectonic setting of Mesozoic granitoids (including syenites) in eastern South China. In the Early Mesozoic, granitoids of variable compositions were intruded in the Cathaysia Block which by this time had developed a thickened and highly differentiated...

Recycled oceanic crust (ROC) has long been suggested to be a candidate introducing enriched geochemical signatures into the mantle source of intraplate basalts. The different parts of oceanic crust are characterized by variable oxygen isotope compositions (δ¹⁸O=3.7‰ to 13.6‰). To trace the signatures of ROC in the mantle source of intraplate basalt...

Mantle metasomatism by percolating melts/fluids can significantly modify the geochemical and mineralogical compositions of the sub-continental lithospheric mantle (SCLM). We present a detailed study of water contents and Li concentrations and isotopic compositions in mantle minerals from a suite of peridotite xenoliths entrained by a Cenozoic Strom...

Understanding the concentration and distribution of water in the Earth's mantle plays a substantial role in studying its chemical, physical and dynamic processes. After a decade of research, a comprehensive dataset of water content in upper mantle samples has been built for eastern China, which is now the only place with water content data from suc...

How the materials derived from the stagnant Pacific slab contributed to the mantle sources of the mafic rocks in east China is still in hot debate. In this work, δ18O (V-SMOW) values of clinopyroxene phenocrysts in the OIB type mafic rocks from 106 Ma to 60 Ma in the east North China Craton (NCC) were measured by secondary ion mass spectrometry (SI...

The subduction of oceanic slabs is widely accepted to be a main reason for chemical heterogeneities in the mantle. However, determining the contributions of slabs in areas that have experienced multiple subduction events is often difficult due to possible overlapping imprints. Understanding the temporal and spatial variations of source components f...

Both mantle-derived clinopyroxene and orthopyroxene are generally homogeneous in water concentration, while water content in the coexisting olivine is affected by partial or complete loss during the ascent of the hosting magma. Here, we report the first record of water content profiles (higher water in the cores than in the rims) in natural orthopy...

Various enriched recycled oceanic components in the source of Cenozoic intra-plate alkaline basalts from eastern China were identified by previous studies. Due to the existence of a stagnant subducted Pacific slab in the mantle transition zone beneath eastern China, it is logical to connect the stagnant slab to the recycled oceanic materials. Howev...

Metasomatism induced by melts/fluids is ubiquitous in the lithospheric mantle and can potentially modifies the initial water content of the mantle. However, the preservation of correlations between H2O content and partial melting indices (e.g., Yb content in clinopyroxene, Cr/(Cr + Al) in spinel) and the lack of correlations between H2O content and...

As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>105 km3) within short time span (<1–3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H...

The aim of this study was to determine both ‘water’ contents (as OH− and H2O) and δD values of several clinopyroxene samples from alkaline basalts. These parameters were first obtained from five clinopyroxene samples using both the classical ‘off-line’ vacuum extraction technique and the ‘on-line’ high-temperature pyrolysis technique. Blanks measur...

The major and trace elements and H2O contents of minerals in peridotite xenoliths hosted by the Cenozoic basalts in Northeast China (NEC) were evaluated using electron microprobe, laser-ablation inductively coupled plasma-mass spectrometry and Fourier transform infrared spectroscopy, respectively. Although a potential loss of H during the xenoliths...

The magma water contents and cpx δ18O values in alkali basalts from the Fuyanyshan (FYS) volcano in Shandong, eastern China, were investigated by an inverse calculation based on the water content of clinopyroxene (cpx) phenocrysts, the ivAlcpx-dependent water partitioning coefficient Dwatercpx/melt, and secondary ion mass spectrometer, respectively...

To quantify the effects of hydration on anharmonicity of olivine thermodynamics, we have measured in situ Raman spectra of an extremely hydrous forsterite with 4500 ppm (wt) H2O at temperatures up to 1273 K. All the Raman modes in hydrous forsterite shift linearly to lower wavenumbers with increasing temperature. The calculated isobaric mode Grünes...

Water has become an effective means to trace the mantle source of basaltic magmas recently. To investigate the source of the potassium-rich component in the Xiaogulihe ultrapotassic volcanic rocks of NE China, we measured the water content of clinopyroxene (cpx) phe-nocrysts by Fourier transform infrared spectrometry and calculated the H 2 O conten...

The in situ Raman spectra of a hydrous anorthoclase at temperatures of 20–800 °C have been measured using a LABRAM-HR spectrometer and Linkam TS 1500 heating stage. The frequencies of modes at 54, 99, 130 and 162 cm−1 related to M–O vibrations decrease sharply and then increase drastically or keep steady at temperatures above 200 °C. A knee point c...

The hydrogen mobility in andradite single crystals from an iron-skarn deposit was investigated through H-D and D-H exchange experiments. Thin slices were annealed in a horizontal furnace flushed with a gas mixture of Ar/D2(10%) and Ar/H2(10%) at ambient pressure between 400 and 700 °C. FTIR analyses were performed before and after each annealing ru...

The genesis of Cenozoic continental basalts in Eastern China is highly debated. Subducted oceanic crust (most probably the Pacific oceanic slab) has been increasingly suggested to be involved in their mantle source. The Taihang Mountains are located at a surface position corresponding to the western edge of a stagnant subducted Pacific slab reveale...