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氟是磷灰石的重要化学组成之一[1]。磷块岩和磷灰石中氟的测定,对磷灰石类型的鉴定和磷块岩的成因研究有重要意义。目前,氟的测定方法广泛地采用酸、碱溶(融)样,用蒸馏法进行元素分离[2,3,4]。近十几年来,由于离子选择电极法操作方便,被广泛地应用于各种类型物质中氟的测定[5]。离子交换剂可以用来分解某些难溶性的天然和合成材料,但是至今这个方法还未得到广泛地应用。 相似文献
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海南岛南岸的珊瑚礁,是我国全新世珊瑚岸礁最为发育的地区之一,仅次于台湾岛南端的恒春半岛沿岸。前人从生物学[1-5]、地貌学[6-8]和地质学[9-12]角度对海南岛南岸的珊瑚礁进行过较为广泛的研究。作者报道过崖县鹿回头水尾岭剖面珊瑚礁样品的C14年代测定结果[13,14]。1979年底至1980年初,作者在海南岛南岸东起小东海沿岸西至西瑁岛西岸地区进行了野外调查与采样。根据野外和室内分析资料,本文公布了一批新测试的C14年代数据,并进一步讨论了全新世珊瑚礁的发育历史及其与海岸变迁、海面变化和地壳运动的关系等问题。 相似文献
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石英颗粒表面结构类型以及它们和形成环境间的对应关系,国外已有初步总结[1,2,3]。对石英颗粒表面结构应用于历史环境分析,有着不同的意见[4-6]。多数研究者认为,对于松散的或未固结的沉积物(主要为第四纪的)中的石英颗粒表面结构,具有显著的环境分析意义,而对于地质年代久远、早已半固结或固结成岩的则看法不一,有的则予以否定。因为,地质年代愈老,成岩作用(包括浅变质作用)影响也就愈大。但也有些情况表明[7,8],虽已固结成岩,其物源区的搬运、沉积过程中产生的机械结构,仍然部分或大部分被保存下来,仍可以指示其环境。 相似文献
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苏州高岭土矿床可划分为两种成因类型[1,2],即风化型1)和热液蚀变型。高岭土集中分布在阳山东、西、北三个矿区。本文仅就阳西风化型高岭土中产出的不同种类高岭土矿物的形成及其互相演变的关系作初步探讨。 相似文献
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矿物中的水分为结晶水,结构水(氢氧根)、层间水、沸石水和吸附水等几种结构状态。不同结构状态的水对矿物的性质应有不同的影响。但是著名矿物学家拉尔森[1](E.S.Larsen)给定矿物中水的比折射度k值(又称格拉斯顿-代尔常数),不论是对何种结构状态的水都适用。曾经有许多人对这一点产生过疑义,最近曼达利诺[2](J.A.Mandarino)修正k值时,对各种结构状态的水仍是同用一值。矿物中各种水的折射度是否变化呢?本文作者将列举大量数据来说明这一问题。 相似文献
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云南东川地区,元古界昆阳群落雪白云岩中规模巨大的层状铜矿,1941年由谢家荣命名为“东川式铜矿”[1],用以代表与闪长岩有关的岩浆热液矿床。李洪谟、王尚文(1941年)、孟宪民等(1948年)[3]对这一成因观点都有详细的论述。1960年后,孟宪民指出,东川铜矿可能为沉积成因。笔者在东川白锡腊、因民、落雪、汤丹等地,发现铜矿床中保留了很多沉积成岩的标志,同时根据脉状铜矿是变质脉、岩浆岩的同位素年龄小于层状铜矿等特征,从而提出了沉积变质的成因认识。1975年,桂林冶金地质研究所提出此类矿床应更名为火山—沉积—浅变质矿床[4]。近年来,通过对含矿层的岩相和岩石学的研究、铜矿与藻类叠层石关系的研究,笔者认为,“东川式铜矿”的成因不是单一的,是沉积成岩、蒸发成岩、变质改造等多成因、多阶段形成的一种复合矿床,本文就此进行了探讨。 相似文献
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昂仁组是一套复理石和类复理石沉积,含晚白垩世土伦期的菊石Mammites[1,2],但因未发现直接的上覆地层和化石稀少而不能肯定是否还包括晚于土伦期或至早第三纪的沉积[1,3]。1980年,笔者在昂仁、萨噶一带的昂仁组中采到瓣鳃、腹足化石;我局区调队在仲巴县错江顶一带,发现连续沉积于昂仁组之上,整合于下第三系之下一套含Masstrichtian期菊石(Sphenodiscus)的杂色地层。本文报道这一发现和对昂仁组时代问题的认识(图1)。 相似文献
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关于鄂尔多斯断块[1]及其周缘的寒武纪地层与海侵,卢衍豪先生曾有论述。本文将讨论“霍山砂岩”的时代及其时侵的特点。 相似文献
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Yu. V. Seryotkin G. A. Pal’yanova V. V. Bakakin K. A. Kokh 《Physics and Chemistry of Minerals》2013,40(3):229-237
Gold–silver sulfoselenides of Ag3Au(Se,S)2 series—Ag3AuSe1.5S0.5, Ag3AuSeS, and Ag3AuSe0.5S1.5—have been synthesized by fusing the elements in the required stoichiometric amounts in evacuated quartz ampoules. The single crystal X-ray diffraction data indicate the existence of two solid-solution series: petzite-type cubic Ag3AuSe2—Ag3AuSeS (space group I4132) and trigonal Ag3AuSe0.5S1.5—Ag3AuS2 (space group $ R\overline{3} c $ ). Both crystal structures differ in the distribution of Ag+/Au+ cations in the same distorted body-centered cubic sublattice of chalcogen anions. The morphotropic transformation results from the shrinkage of anion packing accompanied by the shortening of Ag–Ag distances. The structure of uytenbogaardtite mineral, earlier incorrectly interpreted as a tetragonal or cubic cell, is similar to that of the trigonal Ag3AuS2 end-member. 相似文献
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Lisiguangite, CuPtBiS3, is a new mineral species discovered in a PEG-bearing, Co-Cu sulfide vein in garnet pyroxenite of the Yanshan Mountains, Chengde Prefecture, Hebei Province, China. It is associated with chalcopyrite and bornite, galena, minor pyrite, carrolite, molybdenite and the platinum-group minerals daomanite (CuPtAsS2), Co-bearing malanite (Cu(Pt, Co)2S4) sperrylite, moncheite, cooperite and malyshevite (CuPdBiS3), rare damiaoite (Pt2In3) and yixunite (Pt3In). Lisiguangite occurs as idiomorphic crystals, tabular or lamellae (010) and elongated [100] or as aggregates, up to 2 mm long and 0.5 mm wide. The mineral is opaque, has lead-gray color, black streak and metallic luster. The mineral is non-fluorescent. The observed morphology displays the following forms: pinacoids {100}, {010}, {001}, and prism {110}. No twining is observed. The a:b:c ratio, calculated from unit-cell parameters, is 0.6010:1:0.3836. Cleavage: {010} perfect, {001} distinct, {100} may be visible. H Mohs: 21/2; VHN25=46.7-49.8 (mean 48.3) kg/mm2. Tenacity: brittle. Lisiguangite is bright white with a yellowish tint. In reflected light it shows neither internal reflections nor bireflectance or pleochroism. It has weak to moderate anisotropy (blue-greenish to brownish) and parallel-axial extinction. The reflectance values in air (and in oil) for R3, R4 and (imR3, imR4), at the standard Commission on Ore Mineralogy wavelengths are: 37.5, 35.7 (23.4, 22.3) at 470 nm; 38.6, 36.5 (23.6, 22.6) at 546 nm; 39.4, 37.5 (23.6, 22.7) at 589 nm and 40.3, 38.2 (23.7, 22.9) at 650 nm. The average of eight electron-microprobe analyses: Cu 12.98, Pt 30.04, Pd 2.69, Bi 37.65 and S 17.55, totaling 100.91%, corresponding to Cu1.10(Pt 0.83, Pd0.14)Σ0.97Bi0.97S2.96 based on six atoms apfu. The ideal formula is CuPtBiS3. The mineral is orthorhombic. Space group: P212121, a=7.7152(15)?,b=12.838(3)?, c=4.9248(10)?, V=487.80(17)?3, Z=4. The six strongest lines in the X-ray powder-diffraction pattern [d in ? (I) (h k l) are 6.40(30)(020), 3.24(80)(031), 3.03(100)(201), 2.27(40)(051), 2.14(50)(250), 1.865(60)(232). 相似文献
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Gold–silver sulfoselenides of the series Ag3AuSexS2–x (x = 0.25; 0.5; 0.75; 1; 1.5) were synthesized from melts on heating stoichiometric mixtures of elementary substances in evacuated quartz ampoules. According to X-ray single-crystal analysis, compound Ag3Au1Se0.5S1.5 has the structure of gold–silver sulfide Ag3AuS2 (uytenbogaardtite) with space group R3c. The volume of this compound is 1.5% larger than that of the sulfide analog. According to powder X-ray diffraction, compounds Ag3AuSe0.25S1.75 and Ag3AuSe0.75S1.25 also show trigonal symmetry. Compounds Ag3AuSeS and Ag3AuSe1.5S0.5 are structurally similar to the low-temperature modification of gold–silver selenide Ag3AuSe2 (fischesserite) with space group I4132. These data suggest the existence of two solid solutions: petzite-type cubic Ag3AuSe2–Ag3AuSeS (space group I4132) and trigonal Ag3AuSe0.75S1.25–Ag3AuS2 (space group R3c).It was found that fischesserite from the Rodnikovoe deposit (southern Kamchatka) contains 3.5–4 wt.% S. At the Kupol deposit (Chukchi Peninsula), fischesserite contains up to 2.5 wt.% S and uytenbogaardtite contains up to 5.3 wt.% Se. At the Ol’cha and Svetloe (Okhotskoe) deposits (Magadan Region), uytenbogaardtite contains up to 0.5 and 1.8 wt.% Se, respectively. Literature data on the compositions of silver–gold selenides and sulfides from different deposits were summarized and analyzed. Analysis of available data on the S and Se contents of natural fischesserite and uytenbogaardtite confirms the miscibility gap near composition Ag3AuSeS. 相似文献
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Argentian mercurian gold,golden-yellow in colour,is a variety of native gold containing Ag and Hg,coccurring as hexagonal and tetragonal crystals in hairy,milk-droplet or irregular forms.Its microhardness Hv=91kg/mm^2,equivalent to 3.04on Mons‘scale,and the reflectance is 70.35%(589nm).Chemical analysis gave:Au 56.05-67.33,Ag18.29-31.06 and Hg 10-14.82%,as well as minor Cu.In a few samples Bi or Fe was also detected.The simplified formula is (Au0.52Ag0.36Hg0.09Cu0.02)0.99.X-ray analysis suggests the mineral is of isometric system,with space group=Oh^5-Fm3m,a0=0.40803nm,V=0.06739nm^3,and Z=4.Argentian mercurian gold occurs in a Ag-multimetal deposit at Xiacun,Baiyu County,Sichuan Province,As observed in the mining district,the mineral is distributed along the fissures of the main metallic minerals pyrite,tetrahedrite,chalcopyrite,arsenopyrite,galena,sphalerite,etc.,or in the sulfide veinlets developed in the.fissures of these minerals.Also found in the mineral deposit are native gold,argentite,sulvanite,bournonite,boulangrite,etc. 相似文献
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A. G. Mochalov M. D. Tolkachev Yu. S. Polekhovsky E. M. Goryacheva 《Geology of Ore Deposits》2007,49(4):318-327
Bortnikovite, a new mineral species that is an intermetallic compound of Pd, Cu, and Zn with the simplified formula Pd4Cu3Zn has been detected at the unique Konder placer deposit in the Ayan-Maya district, Khabarovsk krai. The primary source of this placer is a concentrically zoned alkaline ultramafic massif. The X-ray diffraction pattern is indexed on the assumption of a tetragonal unit cell: a = 6.00 ± 0.02 Å and c = 8.50 ± 0.03 Å, V = 306 ± 0.01 Å3, Z = 3, probable space group P4/mmm. The calculated density is 11.16 g/cm3; the mean microhardness VHN is 368 kg/mm2. In reflected light, the new mineral is white with a slight grayish beige tint; bireflectance, anisotropy, and internal reflections are not observed. The reflectance spectrum belongs to the concave group of the anomalous type. The measured values of reflectance are as follows: 56.9 (470 nm), 61.7 (546 nm), 63.4 (589 nm), and 65.4% (650 nm). The new mineral is intergrown with isoferroplatinum, titanite, perovskite, V-bearing magnetite, bornite, and chlorite. The origin of bortnikovite is related to the effect of alkaline fluid on ultramafic rocks. The new mineral is named in honor of Professor Nikolai Stefanovich Bortnikov, a prominent mineralogist and researcher of ore deposits and a corresponding member of the Russian Academy of Sciences. Bortnikovite is the first platinum group mineral that contains Zn as a major mineralforming element. 相似文献
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The 7.1 Ma Broken Hills adularia-sericite Au–Ag deposit is currently the only producing rhyolite-hosted epithermal deposit in the Hauraki Goldfield of New Zealand. The opaque minerals include pyrite, electrum, acanthite (Ag2S), sphalerite, and galena, which are common in other adularia-sericite epithermal deposits in the Hauraki Goldfield and elsewhere worldwide. Broken Hills ores also contain the less common minerals aguilarite (Ag4SeS), naumannite (Ag2Se), petrovskaite (AuAgS), uytenbogaardtite (Ag3AuS2), fischesserite (Ag3AuSe2), an unnamed silver chloride (Ag2Cl), and unnamed Ag?±?Au minerals. Uytenbogaardtite and petrovskaite occur with high-fineness electrum. Broken Hills is the only deposit in the Hauraki Goldfield where uytenbogaardtite and petrovskaite have been identified, and these phases appear to have formed predominantly from unmixing of a precursor high-temperature phase under hypogene conditions. Supergene minerals include covellite, chalcocite, Au-rich electrum, barite, and a variety of iron oxyhydroxide minerals. Uytenbogaardtite can form under supergene and hypogene conditions, and textural relationships between uytenbogaardtite and associated high-fineness electrum may be similar in both conditions. Distinguishing the likely environment of formation rests principally on identification of other supergene minerals and documenting their relationships with uytenbogaardtite. The presence of aguilarite, naumannite, petrovskaite, and fischesserite at Broken Hills reflects a Se-rich mineral assemblage. In the Hauraki Goldfield and the western Great Basin, USA, Se-rich minerals are more abundant in provinces that are characterized by bimodal rhyolite–andesite volcanism, but in other epithermal provinces worldwide, the controls on the occurrences of Se-bearing minerals remain poorly constrained, in spite of the unusually high grades associated with many Se-rich epithermal deposits. 相似文献
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A. Y. Barkov R. F. Martin Y. P. Men'shikov Y. E. Savchenko Y. Thibault K. V. O. Laajoki 《Contributions to Mineralogy and Petrology》2000,138(3):229-236
The new mineral species edgarite, FeNb3S6, was discovered in a feldspar-rich fenite, in a fenitized xenolith enclosed by nepheline syenite of the Khibina alkaline complex, Kola Peninsula, northwestern Russia. It occurs as platy inclusions (up to 0.15?mm) in Ti-(V)-rich pyrrhotite and ferroan alabandite, and as dark gray aggregates of platy grains located on the surface of the pyrrhotite. The associated minerals include Ti-(V)-rich marcasite, Mn-Fe-rich wurtzite-2H, corundum, nearly end member phlogopite, rutile, monazite-(Ce), and a graphite-like material. Edgarite is soft (VHN5;10= 135–205?kg/mm2), distinctly bireflectant, and has a strong anisotropy. Its reflectance in air (and in oil) (R1 and R2 in percent, respectively) is: 470?nm: 28.1, 40.2 (13.0, 24.2), 546?nm: 27.4, 39.3 (12.3, 22.7), 589?nm: 27.0, 38.5 (12.2, 21.7), and 650?nm: 27.0, 36.9 (12.4, 20.3). The composition is Nb 52.87, Fe 10.12, V 0.36, Mn 0.10, Ti 0.04, S 35.86, sum 99.35?wt%, which corresponds to (Fe0.96V0.04Mn0.01)Σ1.01Nb3.03S5.95 (basis: Σ atoms=10). By analogy with synthetic FeNb3S6, the X-ray powder pattern of edgarite was indexed on a hexagonal cell, a=5.771(1), c=12.190(6)?Å, and V=351.6(3)?Å3, D calc is 4.99?g/cm3. The space group is most probably P6322, with Z=2. The strongest lines of the pattern [d in Å (I, hkl)] are: 6.11 (8, 002), 3.04 (6, 004), 2.88 (5, 110), 2.606 (8, 112), 2.096 (10, 114), 1.665 (8, 300), 1.524 (6, 008), 1.126 (7, 322), and 1.027 (6, 414). Edgarite appears to have formed at a very late or final stage of metasomatism, after the main event of fenitization, from a highly reduced, subalkaline S-C-H-rich fluid, which may have remobilized Nb as a result of destabilization of oxide minerals. These reducing conditions promoted the chalcophile behavior of lithophile elements (Nb, Ti, V and Mn) on a local scale in the fenite. 相似文献