黑云母温度计能否用于估计花岗质侵入岩的结晶温度?

为了探讨黑云母温度计是否适用于估计花岗质侵入岩的结晶温度,汇编了国内外典型花岗质侵入体的岩石化学和矿物化学数据,利用Henry等(2005)的黑云母Ti饱和温度计、Li和Zhang(2022)的黑云母全组分温度计估算了岩浆温度,并与Shao等(2020)的锆饱和温度计估算结果进行了对比。结果表明,黑云母Ti饱和温度计估算的温度比锆饱和温度计和黑云母全组分温度计低50~200℃,因此认为黑云母Ti饱和温度计并不适用于估算花岗质侵入岩的结晶温度,而黑云母全组分温度计可以复现S型和I型花岗岩的锆饱和温度计结果。

岩浆储库的活化:以浙江西部马头石英二长岩为例

东南沿海地区发育大量早白垩世晚期到晚白垩世早期的碱性岩,主要为石英正长岩和石英二长岩。然而,这些岩石的成因一直都存在争议。为了明确这些岩石的成因,本论文选择了浙江西部的马头岩体进行研究,分析了其中石英二长岩全岩主微量元素组成和矿物相特征,并结合锆石U-Pb年代学、锆石Hf同位素、锆石微量元素、磷灰石微量元素和斜长石电子探针等技术对其进行了详细研究。锆石U-Pb定年结果显示,马头岩体形成于100±1Ma,属于早白垩世晚期岩浆活动产物。野外观察发现,马头岩体中发育大量的闪长质暗色包体。马头石英二长岩中的锆石ε_(Hf)(t)(-10.4~-0.4)变化极大,表明其是由古老陆壳来源的酸性岩浆与地幔来源基性岩浆混合所形成。马头岩体中的锆石结构十分复杂,在CL图像上普遍显示出黑色的核部、白色的幔部以及黑色的边部。最早期的黑色锆石核部具有相对高的Th、U、Hf含量,变化较大的Eu/Eu^(*)(0.5~0)、Zr/Hf(40~70)和Th/U比值、Ti含量,表明它们结晶自地壳中的演化程度较高的低温且结晶度较高的硅质岩浆储库。白色的幔部锆石具有低的Th、U、Hf含量,Eu/Eu^比值相对较高(0.15~0.37),表明由于基性岩浆的注入导致先存岩浆储库发生活化和熔融,使得岩浆储库内温度升高且熔体比例增加,而随着矿物进一步结晶,晶体间隙之中的熔体演化程度升高,其中结晶了最晚期的具有高U和Hf含量、低Eu/Eu和Zr/Hf的黑色锆石边部。斜长石电子探针数据表明,随着斜长石斑晶的结晶,岩浆储库经历了晶体-熔体分离过程,导致活化后储库内的熔体从富钙向富钠演化,最终结晶形成了细粒状的石英和钠长石。石英二长岩中的磷灰石具有较低的Sr含量(113×10^(-6)~417×10^(-6)),较高的U、Y、轻稀土和较低的重稀土含量,表明先存岩浆储库在经历活化之后,也经历了斜长石、榍石和磷灰石等矿物的分离结晶。锆石记录了岩浆储库的活化和熔融过程,而斜长石和磷灰石等矿物仅记录了岩浆储库活化后的晶体-熔体分离和熔体抽离过程。因此,马头石英二长岩表明其代表岩浆储库活化后经历了熔体抽离的残余岩浆储库,与之同时形成的高硅流纹岩(或高硅花岗岩)是从岩浆储库中抽离出的富硅熔体。最后,我们研究表明岩浆储库在大部分时间内处于低温、低熔体比例的状态,基性岩浆的注入使得先存岩浆储库经历了活化和熔融,这是浅部地壳岩浆储库能再次经历晶体-熔体分离和火山喷发的关键因素。

基于PFC-GBM非均质模型的砂岩裂纹演化细观规律研究

砂岩作为巷道围岩的重要组成部分,其细观损伤特征直接影响巷道围岩岩层稳定性。不同粒径的砂岩其矿物晶体的结构具有较明显的非均质性,为研究砂岩裂纹演化细观规律,综合运用室内试验、数值模拟及理论分析的方法,以现场巷道围岩钻取的三种不同粒径的砂岩试件为研究对象,基于PFC2D软件构建二维等效晶体模型Grain-Based Model(GBM),从细观角度分析非均质砂岩试件破裂过程裂纹演化规律。研究结果表明:砂岩试件颗粒粒径越小,岩石的总接触数量越多且晶间接触占总接触比例越小,单轴加载过程中岩石产生的声发射信号及裂纹内部产生的裂纹数量越多,岩石试件的单轴抗压强度越大且破坏模式越剧烈;三种不同粒径砂岩试件在裂纹演化规律上具有一致性,单轴加载过程中,砂岩内部裂纹演化顺序为晶间拉伸裂纹、晶内拉伸裂纹、晶间剪切裂纹、晶内剪切裂纹;砂岩各矿物晶体内部产生的裂纹数量与矿物含量成正比,与矿物晶体的强度成反比,矿物强度与单位面积裂纹数量系数Kl成反比;砂岩试样破坏时,拉伸裂纹占总裂纹数量的90%以上,拉伸破坏为砂岩在单轴压缩条件下的主要破坏类型。

缓冲液pH值对单晶冰糖色值检测的影响

采用《冰糖试验方法》(QB/T 5010—2016)中的分光光度计法测定单晶冰糖的色值,并研究缓冲溶液p H值对单晶冰糖色值检测结果的影响。结果表明,缓冲溶液pH值为7.0时,单晶冰糖色值的检测结果更为准确。

风云1井抑制碳酸盐岩结晶钻井液技术研究

研究了一套抑制碳酸盐岩结晶的高密度水基钻井液体系及现场复杂防控钻井液技术,安全钻进至完钻井深,全程无事故,不仅消除了低温下盐结晶对井控装备的影响,且阻止了井下盐岩溶蚀的进一步恶化,将有助于玛湖凹陷咸湖沉积环境页岩油的勘探开发。

Geochemical and Sr-Nd-Pb isotopic compositions of volcanic rocks from the Iheya Ridge,the middle Okinawa Trough：implications for petrogenesis and a mantle source

As an active back-arc basin, the Okinawa Trough is located in the southeastern region of the East China Sea shelf and is strongly influenced by the subduction of the Philippine Sea Plate. Major element, trace element and Sr-NdPb isotopic composition data are presented for volcanic rocks from the Iheya Ridge（IR）, the middle Okinawa Trough. The IR rocks record large variations in major elements and range from basalts to rhyolites. Similar trace element distribution characteristics together with small variations in ^87Sr/^86Sr（0.703 862–0.704 884）, ^144Nd/^143Nd（0.512 763–0.512 880） and Pb isotopic ratios, demonstrate that the IR rocks are derived from a similar magma source. The fractional crystallization of olivine, clinopyroxene, plagioclase, and amphibole, as well as accessory minerals, can reasonably explain the compositional variations of these IR rocks. The simulations suggest that approximately 60% and 75% fractionation of an evolved basaltic magma can produce trace element compositions similar to those of the intermediate rocks and acid rocks, respectively. The analysis of their Sr-Nd-Pb isotopic content ratios suggest that the source of the rocks from the IR is close to the depleted mantle（DM） but extends to the enriched mantle（EMII）, indicating that the mantle source of these rocks is a mixture between the DM and EMII end members. The simulations show that the source of the IR volcanic rocks can be best interpreted as the result of the mixing of approximately 0.8%–2.0% subduction sediment components and 98.0%–99.2% mantlederived melts.

Characteristics of Magmatic Rocks and Tectonic Setting of Mazhuangshan Area, East Tianshan, China

The Mazhuangshan area lies in northeast to Aqikekuduke, where are distributed intermediate\|acid rocks, which were formed in the Middle\|Late Carboniferous epoch. The magmatic rocks are peraluminous and belong to calcareous series. All values of ACNK(1.03-\{2.12\}), ANK(1.67-2.93), SI(4.1-33), δ(0.71-4.82), La/ΣREE(0.09-0.26) ΣLREE/ΣHREE(1.76-11.01), (La/Sm)\-N(1.60-6.35), (Sm/Nd)\-N(0.33-0.58), (La/Yb)\-N(4.7-12.1), La\-N/Lu\-X(5.9-11.8), (Ce/Yb)\-N(3.14-6.64), δEu(0.38-\{1.06\}), Rb\-N/Sr\-N(42-120) and Sr\+*(0.02-0.2) demonstrate they vary with DI(\{45-90\}). S\|B diagram also shows that the lithophile elements are abundant in acidic magmatic rocks. Moreover, it is concluded that the primitive magma originated from a subduction zone at the continental edge, and underwent fractional crystallization and contamination, then generated the magmatic rocks. The multi\|cation index (R1: 3055-3993, R2: 286-438) shows that the primitive magma originated from the mantle. All these conclusions are beneficial for exploring gold deposits in the area.

Discovery of Enclaves from Cenozoic PuluVolcanic Rocks in West Kunlun Mountains and ItsGeological Implications

In this paper, we present the occurrence and mineral components of the enclaves firstly discovered in the Cenozoic Pulu volcanic rocks in west Kunlun Mountains, and propose that the enclave is accumulated by fractional crystallization within high-level magma chamber. In addition, the chemical compositions of its primary magma are calculated. The calculated compositions are similar to those of the Kangxiwa volcanic rocks that belong to the same volcanic belt in the Pulu volcanic region, suggesting their origin from the same source region. However, the temperatures and oxygen fugacity of magmas at high-level magma chamber decreased along with fractional crystallization.

Cooling of double crystal monochromator with sagittal focus at SSRF

In SSRF, the design of 1st crystal cooling geometry of double crystal monochromator with sagittal focus is mainly reported by China. Our simulation indicates that the broadening of the full width at half maximum of the rocking curve of the double crystal monochromator induced by the heat load is about 3.7 μrad, and is in agreement with the experimental value of 5 μrad. Our scheme showed that the photon flux is reliably linear with electron current of the storage ring, which is extracted from the monochromator.

The influencing factors and mechanisms of the electromagnetic radiation during rock fracture

Based on the laboratory experiments this paper presented that the primary influence factors about the electromagnetic radiation during rock fracture are the rock mechanics characters and mineral components. The brittle samples and samples contained quartz, pyrite, chalopyrite produce electromagnetic radiation easily. There are three fracture radiation effects. The crystal fracture effect produces the high frequency electromagnetic signals, the piezoelectric effect produces low frequency signals and the natural semiconductor effect produces middle frequency signals possessed distinct wave shapes.

Three Stages of Zircon Growth in Magmatic Rocks from the Pingtan Complex,Eastern China

Morphological and chemical studies on zircon grains from gabbro and granite of the Pingtan magmatic complex, Fujian Province, eastern China, show that there are three stages of zircon growth. The early stage of zircon growth is characterized by colorlessness, high transparence and birefringence, low and dispersive Ipr and Ipy, weak and homogeneous BSE brightness, lower Hf content and depletion of U, Th and Y; the middle stage is characterized by abruptly increasing lpy, progressively strong and sectoral-zoning BSE brightness, higher Hf content and enrichment of U, Th and Y with Th/U 〉 1; the late stage of growth is characterized by brownish color, poor transparence, low birefringence, highest Ipr and Ipy, middle and oscillatorily-zoning BSE brightness, highest contents of Hf, U and Y with Th/U 〈 1. The stages are considered to be formed in a deep magma chamber, ascent passage and emplacement site, respectively. Due to the more or less long residual time of the magma chamber, the difference in age between the early and late stages of zircon might be great enough to be distinguished, which can be attributed to tectonic constraint for the magnlatism.

花岗岩可否分离结晶,有堆晶花岗岩吗?——评学术界最近的一些争论

花岗岩能否分离结晶?世界上有没有堆晶花岗岩?这是学术界长期争论的问题。从近期发表的文献判断,上述争论已经从国际学术界转入国内学术界。国际学术界一直坚持花岗岩能够分离结晶,笔者一直持反对意见。最近,关于堆晶花岗岩的说法突然盛行起来。什么是堆晶岩?堆晶与堆积是一回事吗?斜长石是堆晶矿物吗?这些问题都是需要认真讨论的。众所周知,玄武岩有堆晶岩,花岗岩则主要呈晶粥状态出现,这是两种岩浆粘性不同的表现。花岗岩由于粘性大,晶出的矿物不能下沉,与其晶出的岩浆一起构成类似粥状的面貌,故称为“晶粥”。玄武岩粘性低,晶出的矿物可以下沉离开其结晶的部位在岩浆房底部堆积形成堆晶岩,故玄武岩不形成晶粥。花岗岩形成晶粥后,由于冷却、固结而不可能再次升温熔融造成“晶”与“粥”分离的可能。因此,关于上有高分异花岗岩(或流纹岩),下有堆晶的花岗岩的说法是不可能成立的。堆晶岩、堆晶结构等,统统是外国学者创造的。毋庸置疑,外国学者对花岗岩研究有很大的贡献,现今花岗岩理论的成果基本上都是外国学者提出来的,我们只是在学习、仿效和跟踪。然而,花岗岩研究中也有许多错误的理论、模型、假说,毫无疑问也是外国学者提出来的。面对上述情况,我们只有一个办法:独立思考。学习是必须的,但是,要批判地学,要仔细地鉴别,取其精华,去其糟粕。这样,我们才能更快地进步,才能不至于跟着外国学者犯错误。

Floating-zone growth and property characterizations of high-quality La_(2-x)Sr_xCuO_4 superconductor crystals

We have grown underdoped （х = 0.11, 0.12） and optimally doped （x = 0.16）La2-хSrхCuO4 single crystals by the traveling-solvent floating-zone technique.In order to prepare good quality cuprate crystals,we have made much effort to optimize the preparation procedures.For example,we haveadopted the sol-gel route to prepare a highly fine and homogeneous La2-хSrхCuO4 precursor powder for fabricating a very dense ceramic feed rod used for the floating-zone growth,and we have also used quite a slow growth rate. The high quality of the grown crystals has been verified by double-crystal x-ray rocking curves,with the full-width-at-half-maximum being only 113-150 arcseconds, which are the best data reported so far for La2-хSrхCuO4 crystals.The superconducting critical temperatures of the grown crystals are 30, 31 and 38.5 K for х = 0.11, 0.12 and 0.16 samples, respectively,according to magnetic measurements.

长英质富晶体火山岩成因--岩浆补给与晶粥再活化

火山是人类窥探深部岩浆系统的窗口。从全球范围来看,贫晶体富熔体的火山岩(尤其是玄武岩和流纹岩)大面积出露,而富晶体的长英质火山岩仅出露于破火山周围。长英质富晶体火山岩主要可分为两类:一类是成分和晶体含量均一的火山岩;另一类是成分和斑晶含量分带的火山岩。富晶体火山岩是冷储存晶粥接受岩浆反复补给后重熔、再活化,重新具备流动能力而喷发形成的,储库中先存物质的成分决定了再活化形成的富晶体火山岩的类型。富晶体火山岩的存在能够很好地解释岩浆储库具有较长的寿命而岩浆汇聚结晶的过程却是迅速的这种看似矛盾的现象。虽然近年来长英质富晶体火山岩的研究已经取得了明显的进展,但仍有许多问题亟待解决,如碎斑熔岩的成因,如何判别晶粥活化,晶粥再活化与火山喷发的关系,岩浆补给和晶粥活化的时间尺度等。对富晶体火山岩的进一步研究将有助于深入揭示熔体演化、运移、在浅部的聚集和喷发的机制,并可为建立更完善的长英质岩浆演化模型提供更多信息。

表面接枝C—S—H的岩沥青对高温油井水泥石力学性能的影响

研究了表面接枝C—S—H的岩沥青对高温油井水泥石力学性能和微观结构的影响,采用压力试验机及XRD、TG、SEM和EDS对油井水泥石的力学性能和微观结构进行了测试和表征。研究结果表明,与纯水泥石相比,掺入1%未改性岩沥青的水泥石3 d抗压强度下降了2.98%,而掺入1%表面接枝C—S—H岩沥青的水泥石3 d抗压强度提高了4.26%。物相分析和热重实验表明,表面接枝C—S—H岩沥青的加入不会引起水化产物类型的变化,而掺量为3%表面接枝C—S—H的岩沥青水泥石养护3 d的失重量比纯水泥石高1.01%,说明表面接枝C—S—H的岩沥青可以促进水泥的水化。水泥石的微观形貌和元素分析表明,未改性岩沥青在180℃下热解导致沥青颗粒破碎,而接枝C—S—H的岩沥青表面形成的富Si层可以避免沥青颗粒因气孔而引起破碎,使得未改性岩沥青水泥石界面处的C元素含量较接枝C—S—H的岩沥青水泥石高29.14%,未改性岩沥青水泥石基体中C元素含量较接枝C—S—H的岩沥青水泥石高13.76%。

汇聚环境岩浆氧化态来源的进展与展望

汇聚板块边缘的俯冲带是壳幔相互作用最为强烈的区域,其重要特征是俯冲板片将地表物质带入地球内部并在上覆板块产生强烈的岩浆活动,同时孕育铜、钼、金和其他具有重要经济价值的金属矿床。现有研究显示,俯冲带弧岩浆的氧逸度总体高于洋中脊玄武岩,但对于弧岩浆的高氧逸度的成因存在争议。目前有关弧岩浆高氧逸度的来源存在如下认识:(1)板片俯冲过程中释放的高氧化性流体对地幔楔持续氧化,该流体可能来源于蚀变基性洋壳、上覆沉积物和/或下伏的蛇纹岩化地幔;(2)地幔部分熔融形成的含水熔体与周围地幔反应过程中,还原组分(例如H_(2))的丢失促使氧化性弧岩浆的形成;(3)上升熔体在深部岩浆房演化过程中,富Fe^(2+)矿物相(石榴子石、角闪石等)的分离结晶和/或去气作用致使残余熔体氧逸度升高。本文系统梳理了弧岩浆高氧逸度成因的最新进展,从俯冲带不同来源流体(俯冲沉积物、基性洋壳、岩石圈地幔)的氧化性、地幔尺度内熔岩反应、地壳尺度内弧岩浆分离结晶和去气作用三方面进行系统总结,评述研究现状和争议存在的原因,并对未来研究进行了展望。

估算钙碱性长英质侵入岩结晶压力的地质压力计评述

笔者等对4种常见的矿物压力计(角闪石全铝压力计、黑云母压力计、榍石压力计和“石英”压力计)的适用性进行了经验性检验。基于国内外典型钙碱性长英质岩体的矿物化学和全岩化学成分数据,采用不同压力计估算岩体侵位压力,并与角闪石全铝压力计结果对比。结果表明:角闪石六次配位Al压力计与广泛使用的角闪石全铝压力计的估算值存在系统相关性;榍石压力计计算的压力与角闪石全铝压力计的估计结果相关性较为显著;基于Qtz—Ab—Or简并花岗岩体系的“石英”压力计可以用于估计准铝质—弱过铝质钙碱性(狭义)花岗岩的结晶压力。但是,经验性的黑云母压力计和基于实验数据的黑云母压力压计均不能很好地复现角闪石全铝压力计的结果。黑云母压力计不适用于估算钙碱性侵入岩的结晶压力。

硅质岩浆系统的晶粥活化作用及其岩石学记录

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