一种新的K—Ar和^40Ar—^39Ar等时线—^40Ar／^40K—^36Ar／^40K和^40Ar／^39Ar—^36Ar／^39Ar等时线

通过理论推导，提出了一种新的K－Ar、^40Ar-^39Ar等时线：^40Ar/^40K-^36Ar/^40K、^40Ar/^39Ar-^36Ar/^39Ar等时线。通过实例证明它与其它等时线方法可以进行相互检验。在一些不能利用其它等时线方法的情况下，新的^40Ar/^40K-^36Ar/^40K、^40Ar/^39Ar-^36Ar/^39Ar等时线方法可以充分显示它的使用价值和存在意义。     

辽北法库构造岩系的40Ar/39Ar年代学研究及地质意义

由于缺乏可靠的同位素年代学资料,辽北法库地区的变质岩系一直被看作地台基底型建造,近期研究确认它们属于原岩为深成侵入体和火山-沉积岩系、后经韧性剪切作用而形成的变形变质岩系.它们与遭受同期动力变质作用影响的同构造侵入岩一道构成了规模巨大的法库构造岩系.报道了该套构造岩系中花岗质糜棱岩的40Ar/39Ar同位素测年结果FK53角闪石的256Ma坪年龄和FK51-1黑云母的262 Ma高温坪年龄记录了古生代末洋壳向陆内俯冲或多陆块碰撞背景下发育的花岗岩抬升至浅部地壳层次的冷却年龄,FK51-1黑云母的231 Ma主坪年龄和FK51-2钾长石的227 Ma可能代表了绿片岩相条件下花岗质岩石经历韧性变形作用即法库构造岩系的形成年龄.FK51-2钾长石的年龄梯度197～220 Ma记录了构造岩系形成之后比较平稳的抬升冷却历程,而其180 Ma坪年龄则可能与太平洋板块向华北板块俯冲背景下的构造剥蚀事件有关.同时报道了后期侵入花岗岩的锆石U-Pb和40Ar/39Ar同位素测年结果FK54锆石的U-Pb年龄(159Ma)代表了红土墙子超单元花岗岩的侵入年龄,也界定了法库构造岩系的形成年龄上限,FK54钾长石的125 Ma坪年龄则可能记录了华北板块与西伯利亚板块最终碰撞背景下的构造剥蚀事件.这些同位素年龄记录为重新认识法库断凸之内涵以及华北地台与兴蒙褶皱系的缝合边界提供了重要的年代学约束.     

Combined unspiked K–Ar and 40Ar/39Ar dating applied to the dating of 80–260 ka old Icelandic sub-glacial rhyolites

We have used two techniques (i.e. K–Ar and ⁴⁰Ar/³⁹Ar) on Icelandic obsidian samples to produce and more specially to estimate the quality and accuracy of the ages that can be obtained. Following a meticulous protocol, we were able to date six rhyolitic eruptions with an accuracy 7 to 40 times better than those obtained previously. Among these six rhyolites are the first published K–Ar and ⁴⁰Ar/³⁹Ar ages of Krafla.The combined K–Ar and ⁴⁰Ar/³⁹Ar approach produces not only highly precise but also accurate ages. Such high precision makes it possible to produce accurate reconstructions of ice thickness at a given location and time, to test whether there was a possible link between deglaciation and rhyolitic volcanism onset in Iceland, and to explore other possible applications of the ⁴⁰Ar/³⁹Ar dating method to paleo-environmental and paleo-climatic reconstruction at Iceland's latitude.Then, we investigate, by combining geochemistry (i.e. determination of major and trace element composition) and geochronology (i.e. dating of rhyolitic eruptions via K–Ar and ⁴⁰Ar/³⁹Ar dating) for a number of Icelandic rhyolitic volcanoes whose activity could be recorded in North Atlantic sedimentary cores as well as in Arctic ice. The aim of this approach is to provide new independent anchors and correlations between climate records. Of the six dated eruptions, we propose that one is record in North Atlantic sediments, the Loðmundur eruption that constitutes one of the Kerlingarfjöll tuyas, which we date at 189.9 ± 1.1 ka and assume to be the source of the tephra recognized in core MD04-2822 at a depth of 3630–3631 cm.     

尚义-赤城断裂带中糜棱岩40Ar/39Ar年龄记录及地质意义

黑云母的40Ar/39Ar同位素年龄表明, 尚义-赤城断裂带中的中温糜棱岩形成于泥盆纪早期(399 Ma±), 低温退变质作用发生在石炭纪晚期(263 Ma±). 同位素年龄记录提示, 对华北陆块在古生代的构造活动有重新再认识的必要性; 同时说明了古断裂的复活在板内变形的重要性.     

骑田岭花岗岩~(40)Ar/~(39)Ar同位素年龄及其地质意义

报道骑田岭岩体长石~(40)Ar/~(39)Ar定年的结果.~(40)Ar/~(39)Ar方法定年在骑田岭岩体还是首次应用.测定的3个正长石样品~(40)Ar/~(39)Ar坪年龄(Ma)分别为(139.57±2.79)(2KL 17),(140.55±2.81)(99LQ-2),(144.91土2.90)(2KL-31),上述年龄反映了骑田岭岩体主体芙蓉和菜岭超单元岩浆冷却到正长石Ar-Ar封闭的年龄.可以认为这是岩体形成的最小年龄.其中2KL-31样品采自前人划为菜岭超单元的印支期花岗岩.菜岭超单元和芙蓉超单元年龄相近,与两单元地球化学特征与岩石结构的相似性以及正长石斑晶在几乎全岩体中呈NW-SE定向排列的地质事实相吻合.表明芙蓉与菜岭两个超单元岩体是晚侏罗世同源岩浆分异的产物.对骑田岭岩体和千里山岩体进行了对比讨论.     

骑田岭花岗岩~(40)Ar/~(39)Ar同位素年龄及其地质意义

报道骑田岭岩体长石~(40)Ar/~(39)Ar定年的结果。~(40)Ar/~(39)Ar方法定年在骑田岭岩体还是首次应用。测定的3个正长石样品~(40)Ar/~(39)Ar坪年龄(Ma)分别为(139.57±2.79)(2KL-17),(140.55±2.81)(99LQ-2),(144.91±2.90)(2KL-31),上述年龄反映了骑田岭岩体主体芙蓉和菜岭超单元岩浆冷却到正长石Ar-Ar封闭的年龄。可以认为这是岩体形成的最小年龄。其中2KL-31样品采自前人划为菜岭超单元的印支期花岗岩。菜岭超单元和芙蓉超单元年龄相近,与两单元地球化学特征与岩石结构的相似性以及正长石斑晶在几乎全岩体中呈NW-SE定向排列的地质事实相吻合。表明芙蓉与菜岭两个超单元岩体是晚侏罗世同源岩浆分异的产物。对骑田岭岩体和千里山岩体进行了对比讨论。     

Intercalibration of international and domestic ~(40)Ar/~(39)Ar dating standards

40Ar/39Ar method is a high precision dating means, of which the age is obtained by contrasting the un- known sample with those of standards. Usually the age of standard is determined by K-Ar method in which the 38Ar spike should be added for measurement. However, the absolute concentration of 38Ar spike is measured through the calibrated standards in turn, al- though occasionally the concentration of 38Ar spike is determined by other dating methods, such as Rb-Sr, U-Pb methods, which is kn…     

一种新的K-Ar和~(40)Ar-~(39)Ar等时线——~(40)Ar/~(40)K-~(36)Ar/~(40)K和~(40)Ar/~(39)Ar-~(36)Ar/~(39)Ar等时线

通过理论推导 ,提出了一种新的K -Ar、4 0 Ar - 39Ar等时线 :4 0 Ar/ 40 K - 36Ar/ 40 K、4 0 Ar/ 39Ar - 36Ar/ 39Ar等时线。通过实例证明它与其它等时线方法可以进行相互检验。在一些不能利用其它等时线方法的情况下 ,新的4 0 Ar/ 40 K - 36Ar/ 40 K和4 0 Ar/ 39Ar- 36Ar/ 39Ar等时线方法可以充分显示它的使用价值和存在意义     

西藏芒康盆地内高钾火山岩的40Ar/39Ar年代学和地球化学研究

新获得的两个高精度40Ar/39Ar年龄结果表明, 西藏芒康盆地内拉屋乡组高钾火山岩的形成时代为33.5 ( 0.2 Ma. 元素和Pb-Sr-Nd同位素地球化学示踪结果表明, 高钾火山岩是在转换压缩引起的陆内俯冲背景下产生的, 其可能源区为EM2型富集地幔端元. 高钾火山岩中的高场强元素Nb和Ta出现明显的负异常, 表明在该火山岩的源区内有陆壳物质的加入. 芒康盆地33.5 ( 0.2 Ma的高钾火山岩在时空和物质组成上均与青藏东缘发现的两类高钾岩系中的早期高钾岩浆岩具有可比性, 它们可能形成于相同的构造背景.     

Zur Frage ionosphärisch-troposphärischer Beziehungen

Zusammenfassung Angeregt durch eine Arbeit vonS. Bauer wurde für ein sonnenfleckenarmes bzw.-reiches Jahr nach einer Korrelation zwischen derfoF2 bzw.h'F2 und Kaltfrontdurchgängen gesucht. Im Gegensatz zuBauer wurde keine Beziehung gefunden. Anschließend wurde nach einem Zusammenhang zwischen Ionosphärenstürmen und dem Luftdruck am Boden gefragt. Für den sonnenfleckenarmen Winter 1953/54 ergibt sich ein signifikantes Ergebnis.

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Summary Incited by a paper ofS. Bauer the A. tried to find a correlation betweenfoF2 orh'F2 and cold front passages for a year with a small respectively big number of sun-spots. Contrary toBauer no correlation was found. Further a connection between atmospheric pressure at the ground and ionospheric storms was undertaken. The result for the winter 1953/54 with a small number of sun-spots was significant.

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Vortrag gehalten auf die 6. Allgem. Versammlung der «Società Italiana di Geofisica e Meteorologia» (Genova: 10.–12. April 1958).     

The isotopic composition of atmospheric argon and 40Ar/39Ar geochronology: Time for a change?

A redetermination of the isotopic composition of atmospheric argon by Lee, J.-Y., Marti, K., Severinghaus, J.P., Kawamura, K., Yoo, H.-S., Lee, J.B., Kim, J.S. [2006. A redetermination of the isotopic abundances of atmospheric Ar. Geochimica et Cosmochimica Acta 70, 4507–4512] represents the first refinement since the work of Nier [1950. A redetermination of the relative abundances of the isotopes of carbon, nitrogen, oxygen, argon, and potassium. Physical Reviews 77, 789–793]. The new ⁴⁰Ar:³⁸Ar:³⁶Ar proportions imply <1% adjustments to ⁴⁰Ar/³⁹Ar ages in all but exceptional cases of very young and/or K-poor and/or Ca-rich samples, or cases in which samples are grossly under- or over-irradiated. Analytical protocols employing atmospheric argon to determine mass discrimination corrections are insensitive to the effects of revision on the air correction, but are subject to non-negligible adjustments arising from expanded heavy to light isotope ratios attending the increased mass discrimination correction. The competing effects of increased ⁴⁰Ar/³⁹Ar and ⁴⁰Ar/³⁷Ar ratios render the adjustments a function of sample chemistry and neutron irradiation parameters. The improved precision of atmospheric ⁴⁰Ar/³⁶Ar and ³⁸Ar/³⁶Ar permits increasingly sensitive detection of departures from atmospheric values. Non-atmospheric initial ⁴⁰Ar/³⁶Ar values are increasingly well-documented in volcanic materials, including subatmospheric values correlated with ³⁸Ar/³⁶Ar in a trend consistent with kinetic mass fractionation whereby incomplete equilibration between magma and atmosphere favors light isotope enrichment in the magma. The detailed mechanism(s) of such fractionation are unclear and must be clarified by further study. A detectable increase in atmospheric ⁴⁰Ar/³⁶Ar in the past 800 ka [Bender, M.L., Barnett, B., Dreyfus, G., Jouzel, J., Porcelli, D., 2008. The contemporary degassing rate of ⁴⁰Ar from the Earth. Proceedings of the National Academy of Sciences 105, 8232–8237] suggests that ages of late Quaternary (e.g., <100 ka) materials incorporating large amounts of atmospheric argon such as biotite may be underestimated by as much as 100% if a modern atmospheric ⁴⁰Ar/³⁶Ar value is erroneously assumed, unless air argon is used to determine mass discrimination. Further evaluation of the evolution of paleoatmospheric ⁴⁰Ar/³⁶Ar, and the fidelity with which argon trapped in igneous materials reflects this, would be very productive. The use of isochrons rather than model (e.g., plateau) ages mitigates the vagaries associated with uncertain trapped argon isotope ratios, and the importance of strategies to derive statistically valid isochrons is underscored.     

Stabilität und Labilität im Kaltfrontbereich

Zusammenfassung So wie für das Himmelsbild in einer einheitlichen Luftmasse der vertikale Temperaturgradient die wichtigste Rolle spielt, so erweist sich für den Wetterablauf beim Kaltfrontdurchgang die vertikale Temperaturschichtung im Frontbereich von entscheidender Bedeutung. In den Registrierungen der meteorologischen Elemente zeigt sich meist deutlich der Unterschied zwischen «stabilen» und «labilen» Kaltfronten.

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Summary As significant the part, played by the vertical lapse rate of temperature in the appearance of the sky in uniform airmasses, as determinant for weather conditions during the passage of a cold front is the vertical lapse rate of temperature in the frontal area. Generally, the recordings of meteorological instruments show a pronounced difference between «stable» and «unstable» coldfronts.

     

Huminsäuren natürlicher Gewässer

Ohne Zusammenfassung Ergebnisse der im Juni 1962 in der Math.-nat. Fakult?t der Martin-Luther-Universit?t Halle-Wittenberg vorgelegten gleichnamigen Dissertationsarbeit.     

长乐-南澳韧性剪切带~(40)Ar/~(39)Ar热年代学研究

采自长乐-南澳韧性剪切带的5个单矿物~(40)Ar/~(39)Ar坪年龄分别为107.9 Ma(Mus)、108、2Ma(Bi),107.1 Ma(Bi),109.2 Ma(Hb)和117.9 Ma(Bi),与对应的等时线年龄一致.它们记录了长乐-南澳韧性剪切带的形成时间.样品在不同封闭温度下的年龄重叠说明,作为闽粤沿海碰撞造山带主体之一的长乐-南澳韧性剪切带在形成后(107～118 Ma)经历了快速的初始冷却上升.结合钾长石K-Ar年龄研究和相关的年代学资料表明,该带后期(107～70 Ma)冷却上升速率有所减缓,大约为0.18～1.12mm/a.     

Unregelmässigkeit und Regelmässigkeit der SporadischenE-Schicht

Summary From station's observations much information on top-frequencyfEs, less on blanketing frequencyfbEs is obtained. The results must be interpretated in statistical terms. Time- and distance-correlation functions are established. Daily, seasonal and geographic regularities are discussed. A sharp maximum exists at the magnetic equator but only for the top-frequency. No well defined influence of the solar cycle has been found, only a very weak one of lunar tides.Apart the routine evaluation observations of the variation of the reflection coefficient with frequency have been made. In temperate latitudes in about 1/3 of all cases there is no partial reflection; in the other cases local variations of electron concentration up to 1:2 are found, higher values are rare. At low latitudes the variation may be more important. This is found by a qualitative classification of ionograms of different stations. Such classification has been made for transparency, scatter, angle of incidence and layer developpement. Diffuse echoes exist often near the magnetic equator.Es is always vertically sounded at temperate latitudes. In most cases the ionization originates as a thin layer of constant altitude. Transitory phenomena coming downwards are responsible for «E2s» in daytine.It appears that a cumulo-cirrus-cloud layer is a good model forEs-ionization. An atmospheric ionization process using stored energy from dissociation or ion existence seems to be most probable.     

Erdbebengeräusche

Summary During the year 1946 the seismic activity in the ?Wallis? (Switzerland) was very high. A series of aftershocks has been registrated in the epicentre. At the same time the acoustic phenomenon accompanving the shocks has been observed directly. The different shocks could be classified in two types. The shocks which began as an eyplosion had all a very steep first wavefront (Fig. 2). The shocks which produced the same noise as an approaching heavy car had a very feeble first phase (Fig. 1).

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Résumé L'année 1946 fut une période séismique très active dans le Valais. On eut l'occasion d'observer une grande série de répliques dans l'épicentre avec un séismographe transportable. Les phénomènes acoustiques accompagnant ces secousses et observés directement, sont comparés avec les enregistrements séismographiques. Les secousses se manifestant comme eyplosion ont des enregistrements séismiques très typiques. Le front de la première onde des secousses était très raide (Fig. 2), tandis que les secousses dont le bruit émis ressemblait à une voiture roulante ont eu des précurseurs faibles (Fig. 1).

     

Eisen-Mangan-Grundwässer

Ohne Zusammenfassung