阿尔泰东部新生代火山岩的地球化学特点及构造环境

新疆三大山系均有新生代火山岩,其中南部西昆仑、阿尔金山及天山托云等地的新生代火山岩比较发育,在新疆东北部地区的阿尔泰哈拉乔拉一带也发育新生代的陆内喷发火山岩。这套火山岩虽然面积不是很大,但具有大陆溢流玄武岩的特点。在地球化学上也具有典型热点成因洋岛玄武岩或其它地幔柱成因玄武岩的特点,如TiO2含量高大于2%、轻稀土元素和不相容元素显著富集等。表明新疆北部特别是阿尔泰造山带东部演化到新生代以后,有向裂陷拉张方向演化的趋势,标志着一个新的大地构造演化阶段的到来。     

The eastern continuation of the Cadomian orogen: U–Pb zircon evidence from Saxo-Thuringian granitoids in south-western Poland and the northern Czech Republic

We report U–Pb single zircon ages from three pre-Variscan granitoids in the NE part of the Bohemian Massif. The Platerówka granodiorite from the Lausitz-Izera Unit, the Polish Sudetes, has been dated at 533±9 Ma. The Bitouchov granite form the SW part of the South Krkonoent/1qngf7yk7naqkgrg/xxlarge353.gif" alt="scaron" align="BASELINE" BORDER="0">e Unit, the Czech Sudetes, gave an age of 540+11/–10 Ma, and the Went/1qngf7yk7naqkgrg/xxlarge261.gif" alt="aogon" align="MIDDLE" BORDER="0">droent/1qngf7yk7naqkgrg/xxlarge380.gif" alt="zdot" align="BASELINE" BORDER="0">e granodiorite in the Fore-Sudetic Block yielded 548±9 Ma. All these latest Vendian/Early Cambrian granitoids represent the post-tectonic expression of a late Proterozoic Cadomian orogenic cycle and demonstrate the eastward extent of the Cadomian basement into the Variscan orogen. Granodiorites of similar age have so far been reported from Brittany and especially from the Saxo-Thuringian Terrane to the NE and SW of the Elbe Fault Zone. We conclude that the Saxo-Thuringian Terrane extends across the Elbe and Sudetic Marginal Fault Zones into the Fore-Sudetic Block.     

The Reliability of Assigned Values from the GeoPT Proficiency Testing Programme from an Evaluation of Data for Six Test Materials that have been Characterised as Certified Reference Materials

Assigned values derived from the GeoPT proficiency testing programme were compared with certified values for six certified reference materials that have been used as test materials in the GeoPT programme. Statistical analysis showed that there were few significant differences between these sets of data and that these differences had no significant impact on the GeoPT assessment when fitness‐for‐purpose criteria were taken into account.     

TRMM卫星降水数据在小尺度流域的评估与应用

选取史灌河流域上游黄泥庄站以上集水区域为研究流域,以地面站点观测为基准数据,评估TRMM 3B42V7版本卫星降水数据的精度,并采用上述两种降水数据驱动栅格型新安江模型,模拟黄泥庄站日径流和月径流过程。结果表明:2001~2010年TRMM 3B42V7降水数据与雨量站数据累积量的偏差不大,仅为1.71%,但相关系数较低,采用TRMM降水数据模拟的日径流能基本再现黄泥庄站的日径流过程,但对洪峰的模拟精度较低;TRMM月降水数据精度较高,相关系数为0.96,能够较为精确地模拟黄泥庄站的月径流过程。     

Oxydation expérimentale de Fe-tourmalines et corrélation avec une déprotonation des groupes hydroxyleAnnealing in oxidising conditions of Fe-tourmalines and correlated deprotonation of OH groups

Annealing at 400?<em>Tem>?600 °C (40?<em>Pem>?60 MPa and HM buffer-controlled <em>fem>(O₂)) of tourmalines synthesised at the same <em>Tem> and <em>Pem> with NNO buffer induces an oxidation of Fe²⁺ into Fe³⁺ in some Y sites only (Mössbauer Spectroscopy data). Annealing in the same conditions of natural tourmalines is consistent with these results. FTIR spectroscopy shows that oxidation of Fe²⁺ into Fe³⁺ is charge-balanced by deprotonation of the external OH₍₃₎ groups. <em>To cite this article: Y. Fuchs et al., C. R. Geoscience 334 (2002) 245–249.em>     

Nouvelle interprétation structurale de la « faille Nord- Pyrénéenne » en vallée d'Aspe (Pyrénées-Atlantiques). Remise en question d'un plutonisme ophitique danien dans le secteur de Bedous

In the Aspe Valley (western Pyrenees), the Europe/Iberia boundary corresponds to a complex fracturing zone, called the ‘Bielle–Accous Wrench-Faulting Corridor’, which represents the classical ‘North-Pyrenean Fault’. Located between the High Primary Range and the North-Pyrenean Zone, the BAWC shows different south-verging sheets mainly composed of Triassic materials. The Bedous ophite, associated with Muschelkalk and Keuper sediments, is also Triassic in age and involved in the same Pyrenean thrusting structures. So, contrary to a recent interpretation, this magmatic rock cannot be related to a supposed Danian plutonism inducing metamorphic processes in the surrounding Mesozoic formations. <em>To cite this article: J. Canérot et al., C. R. Geoscience 336 (2004).em>     

L'accident du Toulourenc : une limite tectonique entre la plate-forme provençale et le Bassin vocontien à l'Aptien–Albien (SE France)

The WNW–ESE trending Toulourenc Fault Zone (TFZ) is the western segment of the major Ventoux–Lure Fault Zone, which separates the Provençal platform from the Baronnies Vocontian Basin. The TFZ was subject to polyphased Mid-Cretaceous movements, during the Early Aptian and Middle–Late Albian times. The latter faulting episode generated conglomerates and olistoliths resulting from dismantled faultscarps cutting Barremian–Bedoulian limestones. The deformation is related to compressional wrench faulting (NE–SW sinistral faults; dextral component for the TFZ). It induced the uplift of the northwestern corner of the platform, as indicated by a mid-Cretaceous hiatus (Early Aptian <em>pro parteem> to Early Albian) narrowly delimited in space. The opening of submeridian grabens within the platform favoured the northward transit of channelised coarse-grained Albian sands originating from a southern area. <em>To cite this article: C. Montenat et al., C. R. Geoscience 336 (2004).em>     

赣南中侏罗世流纹岩地球化学及成因研究：上地壳成因的的微量元素和Pb-Nd-Sr同位素地球化学制约

江西南部龙南-寻邬地区余田群菖蒲组的流纹岩形成于中侏罗世(164．8．1Ma～174．9Ma)，为双峰式火山岩组合的酸性端元，属弱过铝质(ACNK平均为1．04)钙碱性系列(σ平均为1．90)。稀土元素含量高(平均为278．9μg/g)，轻稀土富集(IMH平均为7．94)，Eu亏损中等(δEu平均为0．41)。微量元素以富集Rb，Ba，Th，U，Zr，Y，Pb，而亏损Sr，Nb为特征。Pb，Nd，Sr同位素组成为：(^206Pb/^204Pb)t=17．89～18．58，(^207Pb/^204Pb)t=15．58～15．70，(^208Pb/^204Pb)t=37．94～38．82；εNd(t)=-7．44～-11．9；ISr=0．71126～0．71228。对赣南流纹岩微量元素采用蛛网图和模糊聚类分析方法进行对比研究的结果及Pb-Nd-Sr同位素相关特征为其上地壳成因提供了地球化学佐证。赣南流纹岩是由进入上地壳内高位岩浆房的石英拉斑玄武岩浆的底侵作用直接使上地壳部分熔融形成的产物。     

西藏泽当蛇绿岩玄武岩SHRIMP锆石U-Pb年龄 及其地质意义

雅鲁藏布江缝合带中各蛇绿岩体的准确定年对待提斯洋演化和青藏高原隆升的研究具有重要意义.泽当蛇绿岩是雅鲁藏布江缝合带东段最大的蛇绿岩块体,关于其形成年龄目前仍存在不同的认识.通过SHRIMP锆石U-Pb测年得到蛇绿岩中玄武岩的形成年龄为154.9Ma±2.0Ma(95％置信度,MSWD=0.98).蛇绿岩中的玄武岩是洋脊扩张的产物,其形成年龄代表了扩张事件的时间,也代表了蛇绿岩的形成时代.结合已有的雅鲁藏布江缝合带蛇绿岩的形成年龄,该年龄进一步反映出雅鲁藏布江缝合带蛇绿岩形成时间具有东早西晚的特点.泽当蛇绿岩与含有埃达克质英云闪长岩的泽当岛弧火成岩基本为同期形成的.地球化学特征显示定年的玄武岩形成于俯冲带之上,且具有指示洋内俯冲环境的地球化学特征.因此,泽当SSZ型蛇绿岩可能形成于洋内俯冲机制.     

Direct terrestrial-marine correlation demonstrates surprisingly late onset of the last interglacial in central Europe

An interdisciplinary study of a small sedimentary basin at Neumark Nord 2 (NN2), Germany, has yielded a high-resolution record of the palaeomagnetic Blake Event, which we are able to place at the early part of the last interglacial pollen sequence documented from the same section. We use this data to calculate the duration of this stratigraphically important event at 3400 ± 350 yr. More importantly, the Neumark Nord 2 data enables precise terrestrial-marine correlation for the Eemian stage in central Europe. This shows a remarkably large time lag of ca. 5000 yr between the MIS 5e ‘peak’ in the marine record and the start of the last interglacial in this region.