高精度氧同位素测定系统

含氧矿物和岩石氧同位素测试精度主要取决于氧同位素分析样品的制备精度。为了连续稳定地测定高精度的氧同位素数据,笔者等研制了BrF_5—8701氧制备台。本系统具有下列特点:板、块、架分立结构;自动恒温;等阻值并联加热电炉;直播式镍反应器;氩气中路吹除。从而提高了氧制备台的稳定性和制备精度。含氧矿物和岩石的氧同位素测试精度优于0.1‰,测试成功率达100％。     

皖南中生代中酸性侵入岩中黑云母的类型和构造意义

皖南中生代中酸性侵入岩中普遍含有黑云母,按其成分可分为:镁质黑云母、铁质黑云母和黑鳞云母3类,其MF值和∫O_2依次为0.56—0.60,0.42—0.46,0.06—0.13和10~(-12),10~(-14),10~(-18)左右。其寄主岩石的成因类型分别为扬子式同熔型、江南式同熔型和改造型。它们分别占据不同的地区,是不同大地构造单元上的产物。黑云母成分的变化是大地构造环境差异的标志。     

花岗岩锆石中的微量元素的配分特征

花岗岩锆石中的微量元素(铪、铀、钇、钍、磷)的电子探针分析表明,这些元素在花岗岩锆石中皆以类质同象形式赋存,其中最小离子半径的铪以无序固溶体形式与锆完全相溶,而钇和磷在较低温度的条件下常常呈磷钇矿与锆不完全相溶;它们在花岗岩锆石中的地球化学行为是随着结晶环境的物理化学条件的变化而分异的,因此,对它们的分析研究可以揭示花岗岩的成因特征。     

栖霞市马耳夼石英脉型金矿地质特征及找矿方向

马耳夼金矿产于栖霞序列回龙夼单元,岩性主要为英云闪长质片麻岩。区内矿脉受断裂控制明显,成群成带产出,区域性断裂构造与后夼穹形构造交会部位或断裂构造产状变化处是矿体富集的有利部位。NE向断裂、新太古代侵入岩、石英脉是该区金矿成矿的主要控制因素,石英脉为其主要找矿标志,为中低温热液石英脉型金矿床。     

高温高压下元素配分的原位实验与计算模拟研究进展

地球内部元素的配分行为具有重要意义,有助于揭示地球内部物质循环、元素成矿、超临界流体性质等基础地质问题。同步辐射微聚焦X射线荧光光谱(SR-μXRF)结合金刚石压腔(DAC)技术,可以在高温高压条件下实现高准确度和高分辨率的原位(in situ)测试元素在不同物相间的浓度,并获取配分系数。而基于地球化学热力学的理论计算模拟,可以获得元素在不同物相间的赋存形式,有助于揭示元素配分机制。本文综述了SR-μXRF结合DAC技术和地球化学热力学计算模拟原位测定高温高压下元素配分的研究方法,及其在地球内部元素迁移、成矿作用和地球早期形成过程等领域中的应用进展,认为利用该套方法研究高温高压下元素配分行为的体系将变得更加复杂,对温度、压力条件则要求更高。本文旨在更新和丰富高温高压下元素配分系数数据,深化对地球内部物质循环等问题的认知。     

2015/2016年超强El Nio事件背景下我国月预测技巧差异分析

利用中国站点观测降水资料、国家气候中心第2代月动力延伸预报模式(BCC_DERF2.0)的回报和预报数据、NCEP/NACR再分析资料和国家气候中心实时发布的月尺度降水预测评分数据,通过评估和诊断分析发现,在2015/2016年超强El Nio事件背景下,这两年内业务发布的月降水预报能力有明显不同,BCC_DERF2.0对月环流的预测技巧也存在差异:在2015年(El Nio发展位相),降水预报和环流预测技巧较高且稳定,而在2016年(El Nio衰减位相)的预报技巧总体偏低。进一步的研究显示,亚洲—太平洋涛动(Asia-Pacific Oscillation,APO)可能是导致2015年和2016年夏季预测技巧高低的重要影响因素。2015(2016)年夏季为APO低(高)指数年,且2016年具有高指数年的典型环流特征。而APO高指数对应的环流特征与El Nio衰减位相对西北太平洋环流的影响不同,在El Nio和APO的物理影响途径不一致时,将直接影响东亚环流可预报性的高低及动力气候模式的预报技巧,即El Nio在发展和衰减位相与APO型不同组合的影响是2015和2016年月预测技巧有差异的重要原因。     

New data and interpretations of the shallow and deep deformation of Huangtupo No. 1 riverside sliding mass during seasonal rainfall and water level fluctuation

The original Badong County, Hubei, China, was mainly below the highest water level of the Three Gorges Reservoir, which is 175 m above sea level. The new downtown of Badong was rebuilt in the Huangtupo area between 1982 and 1991. After detailed geological investigation in the Huangtupo area, four independent landslides were identified, making it one of the largest and most harmful landslide group in the Three Gorges Reservoir area. Since 2003, abundant data have been obtained from the Huangtupo No. 1 sliding mass about rainfall, water level, earth surface deformation and deep deformation. The monitoring data indicate that the earth surface and deep deformation of this landslide is closely related to the seasonal rainfall and water level fluctuation of the reservoir. During increases in the water level, the earth surface deformation velocity decreases, and then increases obviously in the subsequent water level decreasing stage. Because the water level drawdown period overlaps with the rainy season in this area, the earth surface deformation is affected by both rainfall and water level. The deformation velocity of the earth surface caused by rainfall is about 5 mm/month, while that caused by water level decrease is 5–7 mm/month. On the contrary, the deformation velocity of the deep sliding mass accelerates 2 to 3 times faster than average during water level increase. The distinction of surface and deep deformation regulations indicates that the effects of seasonal rainfall and water level fluctuation on the stability of reservoir wading landslides are different. Based on all monitoring data, we also found that the Huangtupo No. 1 riverside sliding mass is creeping seasonally during the seasonal rainfall and periodic reservoir water level fluctuation. The deformation velocities of the east regions of the sliding body indicate acceleration, making these regions even more dangerous.