法国阿根特拉花岗岩中锆石的微量元素地球化学特征及地质意义

本文以法国阿根特拉花岗岩中的锆石群为例,系统地阐述了锆石的微量元素地球化学的研究方法及其在花岗岩成因探索中的应用。电子探针分析结果表明,阿根特拉花岗岩中的锆石可以划分为四个相:残留相、析离相、主体相和残余相。它们的微量元素(Hf、U、Y、Th、P)配分一方面表明了各自形成环境的不同,再现了岩浆的产生、定位和结晶等阶段的演化机制;另一方面又反映了该岩体的物质以上地壳的组份为主,含有部分深源物质(上地幔或下地壳)。     

ARE ASTEROID 2003 EH1 AND COMET C/1490 Y1 DYNAMICALLY RELATED?

The orbit of asteroid 2003 EH1 is very similar to the mean orbit of the Quadrantid meteoroid stream so that a close relationship between the two is very likely. It has already been suggested that Comet C/1490 Y1 could be the parent of the Quadrantids. If this is the case, then some relationship between the comet and the asteroid might be expected. The orbit of C/1490 Y1 is based on a short observing arc of about 6 weeks and all the observations were with the naked eye, so that its elements are very poorly determined. Hence, forward integration to determine whether asteroid 2003 EH1 represents the re-discovery of the dormant nucleus of C/1490 Y1 is not feasible. Instead we choose to integrate back in time the orbit of 2003 EH1, which is far better determined, and a family of 3500 clones, all of which are moving on an orbit that is consistent with the present known orbit of 2003EH1. We compare the results primarily with the recorded observations of the comet rather than the orbit of the comet derived by Hasegawa. We find that one clone is consistent with these observations.     

Velocity curve analysis of the spectroscopic binary stars RZ Cas,CC Cas,HS Her,HD 93917, V921 Her and Y Cygni by the artificial neural networks

We use an Artificial Neural Network (ANN) to derive the orbital parameters ofspectroscopic binary stars. Using measured radial velocity data of six double‐lined spectroscopic binary systems RZ Cas, CC Cas, HS Her, HD 93917, V921 Her and Y Cygni, we find corresponding orbital and spectroscopic elements. Our numerical results are in good agreement with those obtained by others using more traditional methods (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

基于活动地块边界带的加卸载响应比参数对海城地震中短期预测的应用

地震构造是强震发生的必要基础，强震的孕育和发生与构造密切相关。强震的孕育和发生不仅与震中周围构造有关，而且与孕震区所在的整个构造带有关。这就表明整个构造带的地震活动性与未来强震都有关联，因此，我们在做测震学参数异常预测地震时，必须考虑整个构造带的地震活动。过去我们常以震中周围地区的地震活动资料来做测震学参数的异常分析，可能会丢失部分信息。本文进行了地震构造分区和构造单元的划分，把加卸载响应比参数和张家口一渤海边界带有机结合，对基于活动地块边界带的加卸载响应比参数在海城地震预测中的应用进行了研究，结果预测效果很好。这种方法对边界带的地震危险性判定有某种参考价值。     

Theoretical visibility curves of late type stars

Theoretical visibility curves are presented for one carbon and one oxygen star. We aim to show the importance of measurements at wavelengths across the band.     

Approaches to equilibrium in the distribution of trace elements among the principal minerals in a high-grade metamorphic terrane

X-ray fluorescence, instrumental neutron activation, and particle-induced X-ray emission methods were used to determine the distribution of numerous trace elements among garnet (Grt), Ca-pyroxene (Cpx), hornblende (Hbl), biotite (Bt), plagioclase (Pl) and K-feldspar (Kf) in a high-grade metamorphic terrane within the Grenville Province of the Canadian Shield. Results are presented as distribution formulae, e.g. Sr: Kf 1.1 Pl 16 Hbl 2.2 Cpx 1.0 Bt 1.2 Grt Sc: Hbl 1.1 Cpx 1.0 Grt 7.8 Bt 22 Pl 2.6 Kf V: Hbl 1.15 Bt 2.07 Cpx 6.0 Grt (1.4% CaO)>1 (Pl, Kf) Zn: Bt 1.6 Hbl 1.62 Cpx 2.9 Grt 10 Pl Ga: Bt 1.2 Hbl 1.2 Pl 2.5 Cpx 1.3 Grt where numbers are distribution ratios, e.g. ppm Sr in Hbl/ppm Sr in Cpx=2.2. Examples of inter-element similarities and differences are (a) both Rb and Cs are concentrated in biotite relative to K-feldspar, but for Rb the ratio is 2.3 and for Cs it is 16, (b) the distribution formulae for seven lanthanides are similar except for the position of garnet, e.g. Ce: Hbl 2.7 Cpx 2.8 Pl 1.1 Bt 11 Kf 16 Grt Yb: Grt 2.8 Hbl 2.7 Cpx 9 Pl 1.0 Bt 7 Kf and (c) all of Sr, eight lanthanides, Zr, V and Cr are concentrated in hornblende relative to Ca-pyroxene by a factor that lies in the narrow range of 2.2–3.1. There is a larger variation (departure from the mean) in some distribution ratios than in others. Thus the mean ratios (Hbl/Cpx) for each of six elements and in parentheses the percentage relative standard deviation are Zn 1.62 (8.6), V 2.38 (12), Cr 2.42 (18), Sr 2.7 (28), Ba 2.9 (36) and Ni 1.66 (38). We suggest that variation of this kind is the result of differences from place to place in the magnitude of deformation and recrystallization (which facilitated the rearrangement of atoms), combined with rates of lattice and crystal-boundary diffusion that are unique for the various elements, thus permitting some trace elements to approach equilibrium more closely than others.     

The Ordovician igneous rocks with high Sr/Y at the Tongshan porphyry copper deposit,satellite of the Duobaoshan deposit,and their metallogenic role

A strong link between high Sr/Y arc magmas and porphyry Cu–Mo–Au deposits has been recognized in recent years. The Tongshan and Duobaoshan deposits are representative large Cu–Mo–Au deposits in NE China. We report LA–ICP–MS zircon U–Pb crystallization age of 471.5 ± 1.3 Ma for Tongshan ore-related granitoid. Re–Os isotopic analyses of the two chalcopyrite samples from Tongshan deposit show a model age range of 470.2–477.1 Ma. The Duobaoshan and Tongshan ore-related granitoids show higher Sr/Y and La/Yb ratios. The δ³⁴S values of sulphides from the Duobaoshan and Tongshan deposits vary from −2.3‰ to 0.0‰, belonging to a magmatic-hydrothermal system. The Pb isotopic ratios of the sulphides from the Duobaoshan and Tongshan deposit range from 17.201 to 18.453 for ²⁰⁶Pb/²⁰⁴Pb, 15.445 to 15.551 for ²⁰⁷Pb/²⁰⁴Pb, and 36.974 to 37.999 for ²⁰⁸Pb/²⁰⁴Pb, indicating the addition of lower crustal material. The Duobaoshan and Tongshan granitoids were formed in a subduction-related continental arc setting, produced by partial melting of juvenile hydrous basalts underplating the deep continental crust during the Ordovician.     

厚藤共生真菌(Fusarium oxysporum Y24-2)胞外多糖的化学组成和结构研究

从厚藤共生真菌(Fusarium oxysporum Y24-2)发酵液中提取得到胞外多糖,以Q-Sepharose Fast Flow阴离子交换柱和Superdex S-75凝胶色谱柱对其进行分离纯化,得到纯度高的多糖组分F1S。采用HPGPC和HPLC对F1S的分子量及单糖组成进行分析,结果表明F1S主要由Man、Glc和Gal组成,其摩尔比为1.0∶1.9∶2.1,分子量为37.3kD。F1S的GC-MS和1D,2D-NMR分析表明,该多糖是以→6)-β-Galf(1→为主链,以→2)-α-Glcp(1→,α-Glcp(1→和β-Manp(1→为支链的杂多糖,支链取代于→6)-β-Galf(1→的O-2位。该厚藤共生真菌的胞外多糖为富含呋喃型半乳糖的结构新颖的具有多分支结构的中性杂聚多糖。     

北京房山岩体锆石U-Pb年龄和Sr、Nd、Pb同位素与微量元素特征及成因探讨

本文首次用SHRIMP锆石U-Pb测年法获得房山岩体主期侵入岩-花岗闪长岩的年龄为130．7±1．4Ma,证明房山岩体主体岩石形成于早白垩世。综合该岩体两期侵入宕的常量、微量、稀土元素和同位素及构造环境特征,发现房山岩体侵入岩具有许多与埃达克岩(adakite)极其相似的独特的岩石地球化学特征,但又与Defant和Drummond(1990)定义的典型埃达克岩(O型)有明显差别,与中国东部C型埃达克岩更为接近,或也称之为中国东部燕山期高Sr低Y型中酸性火成岩。本文通过房山岩体Sr、Nd、Pb同位素的系统研究,发现在143Nd／144Nd-87Sr／86Sr图解上,两期岩石投影点均落在EM Ⅰ型富集地幔范围之内,暗示其物质来源与富集地幔有关;钾长石Pb同位素特征也说明房山岩体岩浆来源与EM Ⅰ型富集地幔和下地壳关系密切。结合前人的碳、氢、氧同位素研究成果,认为房山岩体物质来源较深,与上地幔和下地壳有关。此外,发现房山岩体两期侵入岩的εNd(t)值(-13．6--14．2)远高于华北地台区古老下地壳的εNd(t)值(-32--44),而与汉诺坝二辉麻粒岩包体的εNd(t)值(-8--18)近似。由于现有的研究已确证汉诺坝二辉麻粒岩包体是由幔源基性岩浆在晚古生代-中生代时底侵到下地壳底部构成的年青下地壳的一部分,故推测房山岩体的物质来源与华北地台古老下地壳关系不大,而可能与年青下地壳关系密切。在此基础上,提出房山岩体两期岩石形成的两阶段模式:第一阶段可能发生于中生代早期,由于软流体 (层)上涌导致富集岩石圈地幔部分熔融生成带有富集地幔印记的玄武岩浆,该岩浆底侵到下地壳底部,冷却成为年青下地壳的一部分;第二阶段发生于中生代晚期,由于当时软流圈呈蘑菇云状大规模上升,热侵蚀面抬升到壳-幔过渡带,导致早中生代新底侵的玄武质下地壳在榴辉岩-麻粒岩相条件下部分熔融生成C型埃达克质岩浆(也即高Sr低Y型中酸性火成岩浆) 并上侵而成为房山岩体。     

Composition and origin of intermediate solid solutions in the system thorite–xenotime–zircon–coffinite

A comprehensive survey of the accessory-mineral assemblages in Variscan granites of the German Erzgebirge and Pan-African granites from Jordan revealed the occurrence of intermediate solid solutions of the tetragonal thorite–xenotime–zircon–coffinite mineral group with partially novel compositions. These solid solutions preferentially formed in evolved and metasomatically altered, P-poor leucogranites of either I- or A-type affinity. Thorite from the Erzgebirge contained up to 18.8 wt.% Y₂O₃, 16.1 wt.% ZrO₂, and 23.3 wt.% UO₂. Xenotime and zircon have incorporated Th in abundances up to 36.3 wt.% and 41.8 wt.% ThO₂, respectively. Extended compositional gradation with only minor gaps is confined to hydrated members of this mineral group, and is observed to exist between thorite and xenotime, thorite and coffinite, and Y–HREE-bearing thorite and zircon. Complex, hydrous solid solutions containing elevated abundances of three or more of the endmembers are subordinate. Previously reported intermediate solid solutions between anhydrous zircon and xenotime, and anhydrous zircon and thorite, are not observed and are in conflict with experimental work demonstrating very limited miscibility between anhydrous species of endmember composition. The majority of hydrous intermediate solid solutions in the Th–Y–Zr–U system are likely thermodynamically unstable. Instead, they are probably metastable responses to unusual physico-chemical conditions involving various parameters and conditions, the relative importance of which is incompletely known. Leaching and dissolution of preexisting accessory phases during interaction with F-bearing hydrous fluids enriched in Th, Y(HREE), Zr, and/or U, and common deposition of the various elements at disequilibrium (supersaturation) seems to play a key role, but other processes may be of similar importance. Experimental work involving hydrous conditions and complex systems composed of more than two endmembers are needed to shed light into the stability relations of the chemically uncommon compositions treated in this study.