火成岩的分类和命名问题

岩石的分类问题,早在岩石成为地质科学中一门独立的学术领域时就引起人们的重视。1897年于彼得堡(今列宁格勒)举行的第七届国际地质会议,对岩石的分类和命名问题曾列入大会议程进行讨论。当时成立了岩石命名国际委员会。1899年,即第八届国际地质会议(1900,巴黎)的前一年,该委员会举行予备会议,会上俄国和法国的一些学者提出了岩石的分类和草案。大会岩石学小组讨论了他们的方案,并且认为在岩石分类中,占首要地位的     

雅库茨克中部土壤受永久冻土影响的地理分布及成因特征

在特殊的地貌和气候条件下开发西伯利亚针叶林地区的土壤,尤其是永冻土区的土壤。大多数情况下,土壤的地理分布和特征不能局限在水平和垂直的区域性概念的框架内进行解释,我们甚至还要考虑当地土壤形成条件中的地表温度特征。这特性在于特定的土壤形成条件、特有的土壤和植被模式;雅库茨克正是这样一个地区,雅库茨克中部地带土壤类型的形态特征同样具有该特性。     

Genetic impact of the Prestige oil spill in wild populations of a poor dispersal marine snail from intertidal rocky shores

In November 2002, the sinking of the Prestige cargo ship produced an oil spill of 60,000 tons that affected many areas along the Galician coast (in the northwest of Spain). In a number of rocky shore sites, most organisms (particularly marine mollusks) were nearly extinct at a local scale. We tested whether the local bottleneck/extinction that occurred in affected localities caused any detectable reduction of the genetic diversity in the marine snail Littorina saxatilis, an ovoviviparous rocky shore model species characterized by a low dispersal ability, high population density, and wide distribution range. We compared the level of genetic variation and population differentiation between affected (polluted) and control sites located in seven geographical areas (three sites per area, one impacted and two controls, and two replicates per site) one and a half years after the spill. The analysis included molecular marker variation (microsatellite and AFLP loci) and quantitative trait genetic variation for shell variables in embryos extracted from pregnant females. Our results indicate that the affected populations did not show a significant overall reduction in genetic diversity when compared to the controls, suggesting that the species is highly resistant to losing genetic variability as a consequence of a local short-term pollution process in spite of its low dispersal ability and direct development. However, some genetic effects were detected in the polluted populations, particularly for quantitative shell traits and AFLPs, consistent with local adaptations resulting from the fuel contamination.     

Investigation on the Load/Unload Response Ratio With Coda Q-1 as Response

The load/unload response ratio YQ with the geophysical parameter coda Q-1 of the crust as response is denned in this study.The variation in YQ-1 before and after the Northridge earthquake of January 17,1994(California)has been investigated by using the data of coda Q-1 with frequencies of 1.5,3.0,6.0,12.0,and 24.0 Hz in the Southern California from 1987 to 1994.It can be found that YQ-1 for coda waves with all frequencies,the frequency of 12.0 Hz excluded,ascended to a certain extent prior to the occurrence of the rnainshock and returned to normality after the main shock.     

Melt Evolution above a Spontaneously Retreating Subducting Slab in a Three-Dimensional Model

Dehydration of the subducting slab favors the melting of the surrounding mantle.Water content and melt evolution atop a spontaneously retreating subducting slab are reported in a three-dimensional(3-D) model.We find that fluids,including water and melts in the rocks,vary substantially along the trench,which cannot be found in two-dimensional(2-D) models.Their maxima along the subducting slab are mainly located at about 50 to 70 and 120 to 140 km.Volumetric melt production rate changes spatially and episodic...     

On the line profile changes observed during the X2.2 class flare in the active region NOAA 11158

The solar active region NOAA 11158 produced a series of flares during its passage through the solar disk.The first major flare(of class X2.2) of the current solar cycle occurred in this active region on 2011 February 15 around 01:50 UT.We have analyzed the Dopplergrams and magnetograms obtained by the Helioseismic and Magnetic Imager(HMI) instrument onboard Solar Dynamics Observatory to examine the photospheric velocity and magnetic field changes associated with this flare.The HMI instrument provides high-quality Doppler and magnetic maps of the solar disk with 0.5 spatial scale at a cadence of 45 s along with imaging spectroscopy.We have identified five locations of velocity transients in the active region during the flare.These transient velocity signals are located in and around the flare ribbons as observed by Hinode in the Ca II H wavelength and the footpoints of hard X-ray enhancement are in the energy range 12–25 keV from RHESSI.The changes in shape and width of two circular polarization states have been observed at the time of transients in three out of five locations.Forward modeling of the line profiles shows that the change in atmospheric parameters such as magnetic field strength,Doppler velocity and source function could explain the observed changes in the line profiles with respect to the pre-flare condition.     

Age and Geochemical Characteristics of Major Mafic Dyke Swarms in the Southern Part of the Siberian Craton

正Several generations of mafic dyke swarms of different ages and geochemical characteristics cut Precambrian rocks of the southern part of the Siberian craton(Irkutsk Promontory).Each generation of dykes is related to a     

江西会昌密坑山岩体的地球化学及其成因类型的新认识

密坑山岩体是南岭地区与锡成矿密切相关的典型岩体,侵入于上侏罗统鸡笼嶂组流纹质凝灰熔岩及火山碎屑岩中,为一破火山中央岩株侵入体,其主体岩性为钾长花岗岩, Rb Sr全岩等时线年龄为 (124.5± 0.7) Ma.地球化学方面,该岩体具有富 Si、偏碱性、富 K、 Al弱过饱和、 Rb/Sr及 Rb/Ba比值高、 Eu负异常显著、富 Ga、 Ga/Al比值大 (4.14～ 6.77)、富高场强元素 (如 Nb和 Zr)等特点.地质地球化学特征及产出构造背景的综合分析表明,该岩体不是典型的 S型花岗岩,而应属铝质 A型花岗岩.岩体的ε Nd(t)值偏高 (- 3.56～- 5.13),二阶段 Nd模式年龄偏低 (1 207～ 1 326 Ma),反映成岩过程中有地幔组分的参与,属壳幔混源花岗岩.二元混合模拟计算显示成岩过程中地幔物质的混入比例为 53.1%～ 60.0% ,较高含量地幔组分参与成岩过程无疑指示幔源组分对成矿具有重要贡献,这一认识对于进一步揭示南岭地区稀有多金属矿床的成矿机理具有重要意义.     

FORMATION OF THE SINO-U.S. CENTERS FOR SOIL AND WATER CONSERVATION AND ENVIRONMENTAL PROTECTION

1 NEED The ability to achieve and sustain a healthy and functional environment fortifies a country抯 economy and social structure and its ability to share experience and wealth for worldwide benefit. Inadequate attention to environmental conditions and poor or deficient application of land- and water-management technologies, coupled with increasing demands to occupy, use, and reshape the land, produce food, and manage water resources are barriers to using and sustaining natural resources. …