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1.
H.F. STEGER G.H. FAYE W.S. BOWMAN R. SUTARNO 《Geostandards and Geoanalytical Research》1979,3(2):173-175
Under the Canadian Certified Reference Mate-vials Project (CCRMP), four new ore reference materials, one uranium ore BL-5 and three sulphide concentrates (CCV-1, CPB-1 and CZN-1) have been recently issued. The preparation, characterization and certification of these samples are briefly presented. 相似文献
2.
辉钼矿Re-Os同位素定年方法的改进与应用 总被引：13，自引：9，他引：4
公认的Re-Os同位素定年代表物辉钼矿,目前已在金属硫化物矿床年代学研究领域获得了广泛的应用。本研究采用浓HNO3分解辉钼矿样品,大大地简化了Re和Os的化学制备过程,并根据辉钼矿中正常Os含量水平相对放射成因187Os可以忽略的特点,以正常Os标准为稀释剂,实现了仪器测量过程中Os同位素质量分馏的在线校正,改善了分析数据的质量。该方法经辉钼矿国家标准物质进行验证,获得了满意的Re、Os含量及Re-Os年龄数据,并且在南岭地区与连阳复式岩体相关的姓坪夕卡岩型钼矿床成矿年龄研究中获得了成功应用。在实际应用中,为了获得有意义的能反映真实地质事件的年龄数据,辉钼矿样品不仅要有足够的取样量,而且还要保证粒度细、混合均匀。 相似文献
3.
J. W. VALLEY D. R. PEACOR J. R. BOWMAN E. J. ESSENE M. J. ALLARD 《Journal of Metamorphic Geology》1985,3(2):137-153
Abstract Chemical analysis (including H2, F2, FeO, Fe2O3) of a Mg-vesuvianite from Georgetown, Calif., USA, yields a formula, Ca18.92Mg1.88Fe3+0.40Al10.97Si17.81- O69.0.1(OH)8.84F0.14, in good agreement on a cation basis with the analysis reported by Pabst (1936). X-ray and electron diffraction reveal sharp reflections violating the space group P4/nnc as consistent with domains having space groups P4/n and P4nc. Refinement of the average crystal structure in space group P4/nnc is consistent with occupancy of the A site with Al, of the half-occupied B site by 0.8 Mg and 0.2 Fe, of the half-occupied C site by Ca, of the Ca (1,2,3) sites by Ca, and the OH and O(10) sites by OH and O. We infer an idealized formula for Mg-vesuvianite to be Ca19Mg(MgAl7)Al4Si18O69(OH)9, which is related to Fe3+-vesuvianite by the substitutions Mg + OH = Fe3++ O in the B and O(10) sites and Fe3+= Al in the AlFe site. Thermodynamic calculations using this formula for Mg-vesuvianite are consistent with the phase equilibria of Hochella, Liou, Keskinen & Kim (1982) but inconsistent with those of Olesch (1978). Further work is needed in determining the composition and entropy of synthetic vs natural vesuvianite before quantitative phase equilibria can be dependably generated. A qualitative analysis of reactions in the system CaO-MgO-Al2O3-SiO2-H2O-CO2 shows that assemblages with Mg-vesuvianite are stable to high T in the absence of quartz and require water-rich conditions (XH2O > 0.8). In the presence of wollastonite, Mg-vesuvianite requires very water-rich conditions (XH2O > 0.97). 相似文献
4.
河北承德黑山铁矿床热液成矿特征及流体包裹体研究 总被引：3，自引：2，他引：1
黑山大型钒钛磁铁矿矿床产于大庙斜长岩杂岩体中,是承德地区最重要的"大庙式"岩浆型铁矿床。笔者在矿区野外地质观察过程中发现,穿插于斜长岩中的铁磷矿脉、磁铁矿硫化物矿脉有热液成矿作用的显示,表明黑山铁矿床成因除传统认为的岩浆期结晶、熔离、矿浆贯入成矿作用外,还有热液期的成矿作用发生。本文对热液成矿期铁磷矿石中磷灰石和矿化蚀变石英中的流体包裹体进行了显微测温和激光拉曼光谱分析。结果表明,磷灰石中原生包裹体可以分为气液两相包裹体、含子矿物包裹体、含液态CO2三相包裹体、单液相、单气相包裹体5类,均一温度主要集中于180～420℃,盐度主要集中于6.2%～38.9%NaCleq,流体包裹体气相成分主要为CO2、N2和CH4,液相成分主要为H2O,固相成分主要为方解石、石盐、白云石及铁氧化物子矿物。石英中流体包裹体类型和成分与磷灰石中的类似,但固相成分未发现石盐和不透明金属子矿物,均一温度变化于149～422℃,盐度变化于5.7%～22.9%NaCleq。成矿流体为CaCl2-NaCl-H2O-CO2体系,均一温度和盐度呈现正相关连续渐变的特征。铁磷矿石的磷灰石中原生包裹体为流体包裹体,盐度高,子矿物种类复杂,组成中富含CO2和CH4等,这些特征显示成矿流体以岩浆热液为主;成矿机理可能与大气降水对岩浆热液的稀释有关。 相似文献
5.
Abstract— We have analyzed the modal abundances of 23 of the known 24 diogenites in 31 thin sections using an energy dispersive spectrometer (EDS) and automated phase distribution analysis software. Orthopyroxene is predictably the most abundant phase, ranging from 27.7 vol% to 99.8 vol% in these samples. The grand average mode of all the analyzed diogenites includes the “olivine diogenites” but not ALH 85015, a probable howardite, and ALHA81208, a sample with an abundant silica phase. The grand average of these 21 diogenites is: orthopyroxene 92.2 vol%, olivine 4.2 vol%, clinopyroxene 1.2 vol%, chromite 0.9 vol%, plagioclase 0.4 vol%, FeNi metal 0.1 vol%, troilite 0.6 vol%, and silica phase 0.4 vol%. Plagioclase feldspar is extremely depleted in all samples, with modal abundance from none detected to 4.6 vol% in range. Such a low volume of plagioclase may indicate that the diogenite parental melts originated in a source region depleted in Al (Warren, 1985; Stolper, 1975), which is consistent with crystallization from a melt derived from material that had previously experienced extraction of a eucrite-type melt. 相似文献
6.
THORSTEN HOFFMANN JAY R. ODUM FRANK BOWMAN DONALD COLLINS DIETER KLOCKOW RICHARD C. FLAGAN JOHN H. SEINFELD 《Journal of Atmospheric Chemistry》1997,26(2):189-222
Measurements of aerosol formation during thephotooxidation of -pinene, -pinene,d-3-carene, d-limonene, ocimene, linalool, terpinene-4-ol, andtrans-caryophyllene were conducted in anoutdoor smog chamber. Daylight experiments in thepresence of
and dark experiments withelevated ozone concentrations were performed. Theevolution of the aerosol was simulated by theapplication of a gas/particle absorption model inconnection with a chemical reaction mechanism. Thefractional aerosol yield is shown to be a function ofthe organic aerosol mass concentration andtemperature. Ozone and, for selected hydrocarbons, theNO3 reaction of the compounds were found torepresent efficient routes to the formation ofcondensable products. For initial hydrocarbon mixingratios of about 100 ppb, the fractional aerosol yieldsfrom daylight runs have been estimated to be 5%for open-chain hydrocarbons, such as ocimene andlinalool, 5–25% for monounsaturated cyclicmonoterpenes, such as -pinene, d-3-carene, orterpinene-4-ol, and 40% for a cyclic monoterpenewith two double bonds like d-limonene. For the onlysesquiterpene investigated, trans-caryophyllene, afractional aerosol yield of close to 100% wasobserved. The majority of the compounds studied showedan even higher aerosol yield during dark experimentsin the presence of ozone. 相似文献
7.
Bear Mountain Igneous Complex, Klamath Mountains, California: an Ultrabasic to Silicic Cale-Alkaline Suite 总被引：1，自引：0，他引：1
The Bear Mountain igneous complex, Klamath Mountains, California,can be divided into distinct lithologic suites (order accordingto apparent relative age): (1) satellitic masses of clinopyroxene-richultramafic and gabbroic rocks with subordinate dunite and hornblende-plagioclasepegmatoid; (2) two-pyroxene-biotite diorite and monzodiorite;(3) heterogeneous hornblende-rich rocks varying from gabbroto diorite; (4) leucocratic rocks, chiefly consisting of biotitetonalite and granodiorite; and (5) late dikes (mafic to felsic).Elongate masses of unit (1) flank a composite pluton consistingof units (2–4), while the late dikes (unit 5) intrudethe adjacent country rocks. The rocks of the complex invadedan ophiolite allochthon during the Late Jurassic Nevadan orogeny,and well-defined contact aureoles surround the complex. Lowergreenschist facies rocks, chiefly metabasalt, impure siliceousmetasedimentary rocks, and serpentinized peridotite, have beendynamothermally metamorphosed to mineral assemblages indicativeof hornblende-hornfels facies and locally pyroxene-hornfelsfacies. The emplacement of the igneous complex was chiefly byforcible shouldering aside, although local tectonic featuressuch as faults in the ophiolite allochthon were instrumentalin the emplacement history. The ultramafic and gabbroic rocks are interpreted as crystalcumulates of a fractionated basaltic magma. Mineral compositionsand whole-rock chemical characteristics of the proposed cumulatessuggest that the Mg/Fe ratio of the parental basaltic liquidwas high. The activity of silica was low, while water vaporpressure apparently increased through time until it was moderatelyhigh during the late magmatic stage. These cumulates were subsequentlyremobilized during lateral tectonic compression and emplacedhigher in the crust as hot, semisolid aggregates. A diverse array of data, including pyroxene compositions, major-,minor-, and rare-earth-element abundances and field relations,suggest that the two-pyroxene-biotite diorite/monzodiorite unitwas consanguineous with the clinopyroxene-rich ultramafic andgabbroic rocks. The diorite/monzodiorite unit, therefore, isan intermediate differentiate of an early primitive basalt.Furthermore, major-, trace, and rare-earth-element data characteristicof the diorite/monzodionte unit indicate strong similaritiesto low-Si andesite and clearly suggest a calc-alkaline affinity. Age relations indicate that the hornblende-rich and leucocraticunits are younger and represent the intrusion of other magmasinto the same igneous locus. Petrographic and geochemical datafrom the hornblende-rich unit suggest recrystallization fromhydrous magmas similar in composition to high-Al basalt andbasaltic andesite. The leucocratic suite, consisting chieflyof calc-alkaline tonalitic rocks, is similar to other quartz-richfelsic rocks widespread throughout the Klamath Mountains-westernSierra Nevada. The available petrographic and geochemical dataare consistent with formation of these rocks by either fractionalcrystallization of a wet basaltic magma or partial melting ofamphibolite or eclogite. The Bear Mountain igneous complex is an example of a diversebut distinctive association of ultrabasic to silicic rocks whichcharacterize numerous plutonic complexes in the Klamath Mountains-westernSierra Nevada. These intrusive complexes invade older ensimaticrocks and appear to define the roots of a complex, Middle toLate Jurassic calc-alkaline magmatic arc. The ultramafic andgabbroic rocks characteristic of this plutonic association aresimilar to Alaskan-type complexes but differ in detail. Moresignificantly, these rocks are important clues to the compositionof early magmas as well as the complex processes operative inreservoirs that form the core of calc-alkaline magmatic centers. 相似文献
8.
Abstract Oxygen and hydrogen isotope analyses have been made of coexisting quartz, ilmenite, muscovite, and biotite from Late Precambrian metapelitic rocks, staurolite-kyanite to K-feldspar-muscovite-sillimanite zones, from Mica Creek, British Columbia. The δ18 O and †D values of these minerals are generally uniform and do not decrease significantly with increasing metamorphic grade. This implies that there has not been significant infiltration of deep crustal, possibly magmatic, fluids into the metapelites that has been suggested for other high-grade metamorphic terranes. The uniformity of oxygen isotope compositions of the Mica Creek metapelite rocks may reflect isotopic uniformity in the sedimentary protolith rather than widespread exchange with an isotopically homogeneous metamorphic pore fluid.
Temperature estimates based upon18 O exchange thermometry for samples below the sillimanite zone are in reasonable agreement with the results of garnet-biotite Fe–Mg exchange thermometry. In the higher grade rocks, the oxygen isotope and garnet-biotite thermometry yield results which disagree by about 100°C. The highest temperatures recorded by oxygen isotope thermometry, 595°C, are at least 60°C below the minimum temperatures required by phase equilibria. These discrepancies appear to result from pervasive equilibrium retrograde exchange of oxygen isotopes between coexisting minerals. In addition, there are problems with calibration of garnet-biotite thermometry at higher temperatures. Retrograde oxygen isotope exchange may be a general characteristic of high-grade metamorphic rocks and oxygen isotope thermometry may not usually record peak metamorphic temperatures if they significantly exceed 600°C. 相似文献
Temperature estimates based upon
9.
W.S. BOWMAN G.H. FAYE R. SUTARNO J.A. McKEAGUE H. KODAMA 《Geostandards and Geoanalytical Research》1979,3(2):109-113
Four reference soils have been prepared and certified through the cooperation of Energy, Mines and Resources Canada and Agriculture Canada. Their origin and details of preparation and characterization are presented. Thirty-six laboratories participated in the international certification program by providing approximately 16000 results for 65 elements. One or more of the reference soils were certified for 18 elements and preliminary data were obtained for another 47. 相似文献
10.
New mean values for up to 11 major and minor and up to 11 trace elements in soils SO-1 to SO4 have been calculated by two procedures. Analytical results received by CCRMP subsequent to the certification program of 1979 were included. In one instance, the same procedure as used for certification wherein all results except those rejected on chemical and/or statistical considerations was followed, but little improvement over the 1979 calculations was obtained. The other procedure is proposed by the authors for use in identifying concentration range intervals wherein maximum interlaboratory consensus is observed. The application of this procedure has permitted the certification of the four soils for the content of 24 elements not previously certified. 相似文献