Paleoproterozoic granitoids in the southern margin of the North China Craton are important carriers for studying the crustal evolution in Precambrian.In this study,we report zircon U-Pb ages and whole-rock geochemical compositions of the Xiaohe pluton exposed along the southern margin of the North China Craton in order to discuss its petrogenesis and significance for Precambrian crustal evolution.The Xiaohe pluton is composed of biotite-bearing monzogranite,geochemically,which can be divided into two categories according to its rare earth element characteristics.Type Ⅰ shows the right dip distribution mode of light rare earth elements enrichment and heavy rare earth elements depletion,which has the characteristics of medium differentiation.Type Ⅱ has a distribution pattern of rare earth elements with low total rare earth elements,insignificant fractionation of light and heavy rare earth elements,and depletion of middle rare earth elements,which has the characteristics of high differentiation.The zircon U-Pb dating on these two types of granite yielded～1.80 Ga ages for the emplacement time of the magmas,indicating both of them emplaced in single magmatic period.All the analyzed rocks are rich in silica and alkaline and weakly peraluminous,having high-K alkali-calcareous and calc-alkaline characteristics.They are enriched in Rb,Th,U,K,etc.,but depleted in Ba,Sr,P,and Ti.Both types granites have similar Nd-Hf isotopic compositions and their magmas should originate from partial melting of the Late Archean basement rocks along the southern margin of the North China Craton.The magmatism of A-type granite probably represents the tectonics-thermal event closely related to extension,implying a post-collisional/post-orogenic extensional setting along the southern margin of the North China Craton at ca.1.80 Ga.
Leucogranites are widely distributed in the Himalayan orogenic belt and are closely related to rare-metal mineralization.This study focuses on the Nb and Ta mineralization and columbite-group minerals(CGMs)from the granitic pegmatite in the Lalong pluton,eastern Himalayas.Three zones(i.e.,wall zone,intermediate zone,and core zone)can be identified from the Lalong pegmatite based on their lithology.The CGMs mainly exist in the intermediate zone(quartz-feldspar-muscovite zone).Major element,trace element,and U-Pb isotopic compositions of CGMs were systemically analyzed.Two types of CGMs are distinguished by occurrences and chemical compositions.Type Ⅰ CGMs have euhedral occurence and uniform chemical compositions with low Ta#[Ta/(Nb+Ta)]ranging from 0.08 to 0.34.Type Ⅱ CGMs mainly distribute around crystals of the type Ⅰ CGMs or as tiny veins cutting through the type Ⅰ CGMs with higher Ta#ranging from 0.45 to 0.60.Several structures(i.e.,oscillatory structure,metasomatic structure,fissure-filling,and porous)are well developed in the type Ⅱ CGMs.The normalized REE patterns of these CGMs are similar,showing a strong negative Eu anomaly with δEu ranging from 0.001 to 0.020.The LREE/HREE ratio of CGMs ranges from 0.016 to 0.044.Our results indicate a two-staged Nb-Ta mineralization in the Lalong pluton.The first-staged mineralization is related to the magmatic process with the crystallization of the type Ⅰ CGMs,while the second-staged process is late-staged hydrothermal fluid-rich magmatism with the formation of the type Ⅱ CGMs.The REE pattern of the type Ⅱ CGMs,however,is not convincing enough to indicate the magmatic-hydrothermal mineralization.The CGMs U-Pb isotopic analysis reveals the age of Nb-Ta mineralization at 22.3±0.3Ma,implying a rare-metal resource potential of the leucogranites formed in the Neohimalayan period(25-14 Ma).
Leakage has a serious impact on the safe operation of tunnels.In recent years,the distributed optical fiber sensing(DOFS)-based leakage monitoring technology has become one of the hot topics in the field of development and utilization of underground space.In view of the deficiency of the common tunnel leakage monitoring technology,a new temperature-sensitive optical sensing cable for tunnel leakage is developed based on the principle of wet-bulb thermometer,and a DTS-based tunnel leakage distributed sensing method is proposed.The feasibility and the influencing factors of the distributed sensing method for tunnel leakage were investigated and verified through lab model tests.The results show that the developed temperature-sensitive optic sensing cable can be used to accurately identify leakage events.The sensing cable has good repeatability by the experiments of several dry-wet cycles.The influence of the leakage speed,ambient wind speed and leakage duration on the identification of leakage events is insignificant.The threshold criteria for leakage event identification is proposed,i.e.when the relative temperature drop between different sampling points of the sensing cable reaches or is greater than 0.5℃,and the temperature drop rate within 2 hours reaches or is greater than 0.4℃/h,it can be judged as leakage.
The fundamental theory of the fission-track thermochronology has been based on the principle that temperature is the only factor of fission track annealing.However,whether the radiation damage can enhance the annealing or not remains in dispute.This work studies the relationship between radiation damage and the fission track annealing behavior by the apatite fission track dating of four granite samples from Lincang county in Yunnan province.The single grain fission track ages of the samples range from 71 Ma to 15 Ma.The confined track lengths of the samples range from 9 μm to 16 μm and the U concentrations of the samples range from 24 μg/g to 290 μg/g.The analytical results of the relationship between fission track age and length and U concentration show that the fission track age and length decrease wirh increasing U concentration.The relationship preliminarily indicates that the radiation damage could cause and enhance fission track annealing as another factor in addition to temperature.This observation provides evidence for studing fission track annealing behavior caused by radiation damage.
In recent years,biochar has been widely applied as a green and environmentally friendly soil modification material.After the addition to the soil,the physicochemical properties of biochar would be changed by the chemical environment of the soil,thus affecting the volume deformation characteristics of the modified soil.In order to explore the effects of chemically aged biochar on the swelling and compression characteristics of expansive soil,woody biochar was soaking into citric acid solution to simulate the chemical oxidation by plant organic acids,and its mechanism was explained by microstructural analysis(Scanning electron microscopy and Fourier transform infrared spectroscopy).The results show that:(1)The effect of aged biochar on soil swelling behavior is closely related to its particle size and dosage.When the particle size of biochar was fine(<0.25 mm),the enhanced promotion effect of aged biochar on the swelling of expansive soil was only observed in the presence of more biochar;while the enhanced promotion effect was occurred at low dosage with the increase of biochar particle size(0.25-1 mm);(2)The compressibility of biochar amended expansive soil is independent of the chemical aging of biochar,but related to the biochar dosage and particle size.Biochar could reduce the compressibility of expansive soil significantly,and this reduction becomes more pronounced with increasing biochar dosage and decreasing particle size;(3)Chemical aging affects the hydrophilicity of the expansive soil by changing the specific surface area and number of functional groups of biochar,thus the changed swelling properties of the soil;by contrast,the compressibility of the soil is more sensitive to changes in pore structure.
In order to analyze changes in of tectonic deformation and extension mode during the process of eastward compression of Qinghai-Tibet Plateau,the eastern edge of Qinghai-Tibet Plateau is selected as the study area,and apatite/zircon fission track studies were carried out.The results show that many differences between the Zoige Basin and the Longmenshan Block in the aspect of low-temperature geochronology and tectonic uplift:the cooling rates of several samples in the Zoige basin are relatively stable,ranging from 1.257℃to 1.285℃/Myr,while the cooling rates of several samples in the Longmenshan Block changes greatly,ranging from 1.243℃to 2.875℃/Myr;Zoige Basin has experienced two obvious tectonic thermal events since 100 Ma with the first in 100-80 Ma(cooling rate is 4.40±0.395℃/Myr)and the second in 21-12 Ma(cooling rate is 2.89±0.597℃/Myr).The eastern edge of Longmenshan Block has generally shown a gradual increase in the degree of tectonic uplift since 70 Ma,and the uplift has continued to increase since 8 Ma with the cooling rate of 5.75±0.238℃/Myr;The tectonic deformation of Zoige Basin can be classified as forward expansion,while the Longmenshan Block has backward expansion(especially since 8 Ma).The process mentioned above is summarized as"reflection and refraction of tectonic expansion",the"reflection tectonic stress"reached current location of Longriba fault in Pliocene(about 4.48 Ma),with the result of the Longriba fault zone with the features of both thrust and dextral strike slip.
The unsaturated zone,which is the link between the surface water and groundwater,plays a key role in controlling water exchange and solute transport in the soils.Infiltration in the unsaturated zone is in essence a problem of two-phase(air and water)immiscible displacement.A deep understanding of the air-water displacement process in the unsaturated zone is of great significance for the management and sustainable use of groundwater.A series of drainagei-mbibition experiments are carried out to study the water-content distribution in the unsaturated zone.The light transmission method is used to monitor water content in the 2-dimensional sandbox during the drainage-imbibition cycles.It is found that the lateral fluctuation of water content in the drainage process(0.145-0.175)is greater than that in the imbibition process(0.150-0.165)due to the existence of unstable drainage processes at the pore-scale.The difference of water content between drainage and imbibition means that the mechanism happened at pore-scales should also be affected by water movement at darcy-scales.
The eastern Qinling orogen documents two magmatic episodes of granitoids in the Late Jurassic and Early Cretaceous.Their geochemical characteristics,being a petrologic probe for the composition and structure of the deep crust,are distinctly different,pointing to the complex magma sources.In this study,we report zircon U-Pb isotopic ages and whole-rock major and trace element contents and Sr-Nd-Pb isotopic compositions of the Huanghuaman pluton exposed in the eastern section of the North Qinling block.Zircon U-Pb ages indicate that the large-volume biotite monzogranite of the Huanghuaman pluton was emplaced during the 119 Ma to 117 Ma interval.The biotite monzogranites are enriched in large ion lithophile elements and light rare earth elements,but depleted in high field-strength elements and heavy rare earth elements,with significantly negative Eu anomalies and belong to the weakly peraluminous high-K calc-alkaline series.They are characterized by high radiogenic Pb isotopic compositions and relatively depleted Nd isotopic composition with initial εNd values of-5.7 to-4.1.These geochemical characteristics are remarkably different from those of the Late Jurassic granitoids within the North Qinling block and Late Mesozoic granitoids within the southern margin of the North China block.The relatively depleted Nd isotopic composition of the Huanghuaman pluton is similar to those of the coeval Laojunshan in the eastern section and the Early Cretaceous Taibai granite in the western section of the North Qinling block,suggesting that this block underwent large-scale reworking of the juvenile crust during the Early Cretaceous.The juvenile crustal materials might be derived from the mafic rocks within the North Qinling block or the subducted Neoproterozoic crustal rocks of the Yangtze and/or South Qinling blocks.These Early Cretaceous granitoids have different Nd isotopic compositions from those of the Late Jurassic Mangling and Muhuguan plutons in the North Qinling block,reflecting the compositional diversity of the granitoids that were derived from the deeply underlying,complex crustal materials.
Plate tectonics has been regarded as the dominant tectonic regime on the earth today,but what was earth's tectonic regime before the present plate tectonics began and when the present plate tectonics began are still controversial.To understand the evolution of earth and predict its future,we are required to clarify this question.Previously,researchers generally reached a consensus on an uniformitarian view that the early earth's tectonics was similar to the present plate tectonics.However,with the accumulation of geological data and the progress of research technology,the idea of the transition from stagnant lid tectonics to modern plate tectonics was increasingly accepted.The so called"stagnant lid"refers to single plate around earth surface.In this paper,firstly we review the hypothesis of possible tectonic regime models in the early Earth under the background of stagnant lid tectonics,including heat pipe tectonics,plutonic-squishy lid model,mantle overturn and lid-and-plate tectonics.Then we review the latest research of the transition from stagnant lid tectonics to plate tectonics in early Earth.We believe that the mainstream researchers have reached a roughly consistent framework,that is,the transition from stagnant lid tectonics to plate tectonics occurred in the Meso-Neoarchean,and the modern plate tectonics may have formed in the Neoproterozoic.
A digital elevation model(DEM)of the land space ecology at the hydropower project reservoir area could be quickly obtained by the unmanned aerial vehicle(UAV);However,it is rare to focus on the continuous further optimal application of DEM.This study investigated the application of UAV in the rapid modeling and numerical analysis of the land space ecology with a pumped-storage reservoir project.According to the topographic map generated from the DEM,a three-dimensional numerical model was built with the professional numerical software to verify the stress state and perform the stability analysis.The results show that the three-dimensional DEM generated by the UAV was able to highly duplicate the field site,which helped the following indoor numerical studies by scientists and engineers.Besides,based on the regular flying by the UAV,the spatiotemporal status of the land space ecology could be efficiently acquired at a low cost,which allows to achieve the goal of the health monitoring of the land space ecology.
Organic matter is usually enriched in sediments,and will be transformed from disordered carbonaceous material to fully-ordered crystalline graphite,after being buried and heated to some high temperature during metamorphism.The crystalline order is closely corresponding to the certain temperature condition of metamorphism.The Raman spectroscopy(RS)can reflect the vibrational modes of molecules of carbonaceous material(CM),and to reveal the crystalline degrees of graphite,and thus the metamorphic conditions.The RSCM method is an empirical geothermometer by obtaining and analyzing the Raman parameters like band position,peak intensity,band area and FWHM(full width at half maximum)of carbon or graphite grains from a series of metamorphic samples,whose metamorphic temperatures are already known or can be calculated by other methods.A close correlation between the RSCM and peak metamorphic temperature is very well defined,so as to quantitively calculate the peak temperature of the unknown samples during regional or contact metamorphism.Based on the comparisons with the traditional geothermometers,it is suggested that the RSCM is practicable and reliable,and it shows several advantages such as high efficiency,in situ and nondestructive measurements,wide range of temperature detection,high sensitivity to CM inner structures,being free from later retrograde metamorphism,and wide fields of application.Thus,this method is significant for the reconstruction of regional tectonic and thermal evolution,and crustal thermal state.This paper reviews the study history of the RSCM,introduces the theory on CM Raman spectrum band distribution and its relationship with metamorphic temperature,summarizes some representative studies of natural graphitic carbons by Raman spectroscopy in recent years,and its applications in different fields of Earth Sciences.The research foreground of RSCM is finally prospected.
Granodiorite,monzogranite porphyry,and granite porphyry are exposed in the Yangchuling tungsten ore district,northern Jiangxi.The granodiorite and monzogranite porphyry were formed in Late Jurassic and derived from the same source and the latter is more evolved than the former.Tungsten mineralization dominantly occurs as veinlet-disseminated within the monzogranite porphyry which is cut by the granite porphyry dykes.In this contribution,zircon U-Pb chronological,petrochemical,and Sr-Nd-Hf isotope geochemical studies are carried out on the Yangchuling granite porphyry,aiming to reveal the petrogenetic differences between the granite porphyry and the monzogranite porphyry and granodiorite in combination with other published data and provide new constraints for tungsten ore genesis.LA-ICP-MS zircon U-Pb dating manifests that the granite porphyry was formed at 144.6±1.8 Ma which is consistent with those of the granodiorite and monzogranite porphyry.The granite porphyry is high-Si,K-enriched,and weakly peraluminous,shows distinctly Ba-,Nb-,Sr-,P-,and Ti-depleted trace element patterns and rightward-sloping REE patterns with negative Eu anomalies,indicating fractional crystallization of feldspar,biotite,apatite,and Ti-Fe oxide minerals,etc.The granite porphyry has whole-rock(87Sr/86Sr)i,εNd(t),εHf(t),and zircon εHf(t)values of 0.711329-0.711726,-5.3 to-4.9,-4.6 to-4.2,and mainly-6.0 to-3.0,respectively,suggesting that its source is dominated by ancient crustal materials.Compared with the granodiorite and monzogranite porphyry,the granite porphyry exhibits higher HFSE,ΣREE contents,AMF values,Sr/V ratios and lower Mg#values,Ti/Zr ratios,whole-rock εHf(t)values,implying that it was derived from a more felsic source and is the product of partial melting of ancient metasediments.Compared with the monzogranite porphyry,the granite porphyry displays higher SiO2 contents,(Na2O+K2O)/CaO,Na2O/CaO,Ba/Sr,Rb/Sr ratios and lower CaO,MgO,TiO2,P2O5 contents,δEu values,manifesting that it has experienced stronger magmatic fractionation.The barren granite porphyry is reflective of a W-poor source,while the source of the granodiorite and monzogranite porphyry is relatively W-rich.Both the W-rich source and magmatic fractionation facilitate the formation of the Yangchuling tungsten deposit.
知识图谱作为当前最有效的知识组织和服务方式，已经成为人工智能的基石，在语义搜索、机器翻译、信息推荐等方面得到了广泛的应用。大数据时代下，地球科学（以下简称地学）分散、多源、异构数据的整合集成、挖掘分析及其知识的智能发现等迫切需要知识图谱的支撑。为了促进地学知识图谱的建设与应用，自2019年启动以来，“深时数字地球国际大科学计划”（Deep-time Digital Earth,简称DDE）就将知识图谱作为其重要的研究建设内容，经过3年多的建设，DDE已经建设形成了大量的地学知识图谱，亟需一站式共享这些知识图谱。文章首先介绍了DDE知识图谱内容体系，分析了DDE知识图谱内容组成及其特征；在此基础上，开展了地学知识图谱一站式共享服务系统的设计，包括系统功能体系和架构的设计；最后介绍了系统实现的技术路线及其关键技术。实践证明系统可有效实现DDE知识图谱的一站式共享服务，可为类似的知识共享服务系统提供参考。
地质领域实体关系抽取是构建地质知识图谱的基础,对地质领域文本信息抽取与知识库构建具有重要的作用.针对地质领域实体关系复杂、缺少人工标注语料库等特点,提出了面向地质领域实体关系联合抽取模型,着重对多地质文本中存在的复杂重叠关系进行识别,避免传统流水线模型中由于实体识别错误造成级联误差.文章构建了高质量地质领域实体关系语料库,提出了基于预训练语言模型BERT(Bidirectional Encoder Representations from Transformers)和双向门控循环单元BiGRU(Bidirectional Gated Recurrent Units)与条件随机场CRF(Conditional Random Field)的序列标注模型,实现对实体关系的联合抽取.在构建数据集上进行了实验,结果表明,本文提出的联合抽取模型在实体关系抽取上的F1值达到0.671,验证了本文模型在地质实体关系抽取的有效性.
大数据为岩相古地理研究带来了新的思路和挑战,但由于存在数据类型复杂、语义关系丰富、共享机制不明等问题,难以对岩相古地理数据进行深层次的挖掘分析及有效利用,使得大数据的众多优势在该领域得不到充分发挥.知识图谱强大的语义处理能力与开放互联能力,对于解决大数据中文本分析和图像理解等问题发挥着重要作用,具有广阔的应用前景.文章从岩相古地理知识图谱的构建与应用角度,综述了岩相古地理知识图谱的研究背景;系统归纳了岩相古地理知识图谱的构建思路、技术与流程,同时列举出知识图谱在岩相古地理学方面的相关应用;指出了岩相古地理知识图谱存在的主要问题,并对其未来的研究方向提出了展望.
对来源不同的地质对象进行关联匹配,并通过模型对其结构、属性及语义关系进行表示是后期语义查询及聚类等任务的重要支撑.文章针对地质调查空间实体与外部文本描述语义异构、表达差异等问题,提出了一种基于注意力机制的孪生网络地质调查空间实体与文本描述信息关联匹配模型.首先,将地质调查空间实体的属性信息转换成为文本段落,以句向量基本粒度对地质空间实体进行文本语义编码;接着将两类文本对象映射到统一向量空间中,并输入到孪生网络中进行特征学习,最后在构建真实数据集上进行模型性能的实验测评.结果显示,该模型能够较好表示地质调查空间实体句子语义信息,其识别F1值相比基准实验提高了8.4个百分点,优于选取的对比方法.
板块俯冲是板块构造理论的重要组成部分.虽然单板块俯冲的数值模拟研究已经很多,但是多板块之间的相互作用的机制仍然不明确,需要进一步的研究.文章建立了二维的地球动力学数值模型,研究双板片相向俯冲的动力学过程,探讨俯冲板块粘度对多板块耦合作用的影响.模拟结果显示,当两个俯冲板块其他动力学性质相同时,左右俯冲板块的粘度差异会导致板片俯冲速度的不同.粘度小的俯冲板块下沉速度快,先进入下地幔,发生弯曲折叠,并在下地幔堆叠.粘度大的俯冲板块后进入下地幔,受到地幔环流的阻碍,发生翻转,并在下地幔中滑移.左右板片俯冲速度和形态的差异也造成了上覆板块向着粘度小的俯冲板块一侧移动,使得这一侧海沟后退,另一侧海沟前进.该研究结果为东南亚区域的复杂构造的演化过程提供了动力学解释,东南亚区域的印度—澳大利亚板块和太平洋板块相向俯冲,两个板片互相作用,构成了复杂的汇聚俯冲系统,引起的地幔上升流,很可能是南海地区新生代岩浆岩的起源.
近年的探测研究表明,由引力和范德华粘附力聚合成碎石堆结构可能是小行星的一种重要形成方式.为探究这类小行星的演化机制,文章基于离散元软件MatDEM进行二次开发,实现了单元的万有引力计算.建立直径为1.2 km"碎石堆"小行星数值模型,通过数值模拟分析了不同粘附强度和体积密度下,球形聚集体的旋转重塑和破坏过程.结果表明:球形聚集体受到其角速度初始增量的影响,以启动聚集体的重塑过程,导致其发生变形或者破坏;粘附强度越小,模型越容易被破坏,破坏前小行星会通过向扁圆状椭球体变形来保持自身构型的稳定性;对于粘附强度一定的小行星模型,体积密度的增大会有效增加其结构的稳定性,可以延后小行星破坏行为发生的时间,且颗粒脱落的数量随着密度的增大而减少;采用离散元分析可以较好地模拟小行星自旋演化过程.进一步与真实小行星数据相结合,有利于深入、全面地探索小行星自旋演化破坏机理.
近年来川东南地区页岩气勘探开发逐步向深层领域拓展,尤其是泸州地区显示出3500 m 以深页岩气勘探开发的巨大潜力.为了进一步明确泸州地区构造特征及变形机制,依据地震资料对该地区进行了构造解析,采用离散元数值模拟探究了其构造变形的主控因素,恢复了泸州地区中新生代构造演化过程.研究表明:多滑脱层和区域构造挤压是泸州地区构造变形的主要控制因素.受膏盐岩影响,泸州地区发育低陡的盖层滑脱构造,垂向分层明显,形成断展褶皱、滑脱褶皱和滑脱层间隐伏褶皱、双重构造等复合的构造.该区域构造变形主要受下寒武统膏盐岩滑脱作用控制,膏盐岩和页岩滑脱层协调变形向低陡背斜核部聚集.燕山晚期以来,泸州地区多滑脱层沉积伴随区域挤压,发育盖层滑脱的隔档式褶皱;喜山期褶皱带再次隆生,原有的断层和剪切带位移量增大,滑脱层间形成一系列次生断层和隐伏褶皱.背斜处油气藏容易受到破坏,向斜处是页岩气勘探的有利地区,其中对冲型向斜结构相对简单,内部应力相对稳定.
穿地壳岩浆系统理论和晶粥模型为研究中国东南部白垩纪岩浆作用提供了新的思路.大衢山岩体位于浙闽沿海东北部,主体由钾长花岗岩组成,其中发育大量暗色微粒包体(MME),局部可见中—基性岩脉穿插其中,潮头门附近出露少量二长岩.MME具细粒结构,发育针状磷灰石.锆石U-Pb定年结果显示,大衢山岩体出露的钾长花岗岩、MME、二长岩、中—基性岩脉均结晶于～100 Ma.钾长花岗岩硅含量较高(SiO2=68.45%～73.82%).岩体东端可见不含MME的晶洞花岗岩(DQS-7),具有更高硅含量(76.27%),其全岩化学成分与Sr-Nd同位素组成与大衢山周围同期出露的高硅花岗岩体(SiO2＞75%,小洋山岩体,普陀山岩体等)类似.大衢山钾长花岗岩中可见斜长石、钾长石聚晶,与大衢山晶洞花岗岩及周边高硅花岗岩具有Ba、Sr、P等微量元素"互补"的地球化学特征.进一步研究显示大衢山钾长花岗岩是由受到岩浆补给的起源于古老地壳基底重熔的长英质岩浆,经分离结晶和高硅熔体抽离后的残余堆晶固结而成,而高硅熔体形成了大衢山晶洞花岗岩及周边高硅花岗岩.大衢山基性岩脉富集大离子亲石元素,亏损Nb、Ta等高场强元素,与同期出露的浙闽沿海镁铁质岩墙具有相似的地球化学特征,起源于俯冲流体交代的富集地幔.电子探针分析结果表明,钾长花岗岩和MME中的斜长石具有核—幔—边结构,核部(花岗岩27～36、MME 25～41,后同)与边部(17～32、18～26)An值较低,幔部An值(28～57、27～65)相对较高,是岩浆混合作用的典型矿物学标志.结合元素地球化学特征和Sr-Nf-Hf同位素组成,二长岩和中性岩脉应该是幔源镁铁质岩浆与长英质岩浆发生均匀混合的产物,而MME为两种岩浆机械混合的产物.角闪石全铝压力计计算结果表明,MME的形成深度为1.8～3.0 km;二长岩中角闪石发育核—幔—边结构,核部和幔部形成深度为17.0～21.2 km,边部形成深度1.9～4.5 km,指示了不同深度相互连通的两个岩浆房.通过对钾长花岗岩、MME、晶洞花岗岩、二长岩和中—基性岩脉岩石成因及其成因联系的研究,并对比周边同期高硅花岗岩,文章建立了大衢山穿地壳岩浆系统模型.古太平洋板片后撤,沿海地区的弧后伸展和软流圈上涌导致幔源镁铁质岩浆的底侵,并进一步诱发下地壳岩石部分熔融产生长英质岩浆.幔源岩浆的持续补给和加热延长了长英质岩浆房的寿命,发生了分异演化与晶体—熔体的分离,从而形成了深度分别为17～21 km和2～3 km的两个岩浆房.两个不同深度岩浆房中发生的岩浆混合和晶体—熔体分离,最终形成钾长花岗岩、高硅花岗岩、二长岩、MME和中—基性岩脉.
