黄土高原区不同降水相态的时空变化

以1960~2013年黄土高原区及周边58个气象站的地面逐日降水数据为基础,对黄土高原区不同降水相态的时空分布特征进行了分析,研究表明：黄土高原区雨、雪分界线在35°N附近,以北区域以降雪为主,以南且110°E以西的区域以降雨形态为主。该分界线附近是雨夹雪的多发区。黄土高原区降雨有明显的年际波动,而降雪的波动不是很明显,雨夹雪和雾（露、霜）这几种降水相态年际波动较小且趋势一致。液态降水、降雪呈减少趋势,雪、雨夹雪、雾（露、霜）呈增加趋势。雪、雨夹雪、雾（露、霜）均存在显著的准30 a的振荡周期,此外,这4种降水相态还存在15 a、10~12 a、5 a中小尺度的周期。     

昆盖山北坡阿克吐兹—塔西克西韧性剪切带特征

阿克吐兹—塔西克西韧性剪切带位于西昆仑昆盖山北坡 ,该韧性剪切带在空间上具有分带性 ,在时间上具有多期性 ,共划分了 3个构造变形期次。每期构造变形都有其特点 ,反映出该韧性剪切带具有多期构造叠加的属性。根据其组构特征分析 ,韧性剪切带的运动方向是由南西向北东方向运移 ,位移量为 1.94 km。     

Natural alteration products of sulphide mattes from primary lead smelting

The natural alteration products developed on mattes from lead metallurgy were determined: oxides and hydroxides (HFO, Cu(OH)₂), sulphates (thenardite, gypsum), hydroxysulphates (jarosite, beaverite, brochantite) and carbonates (cerussite, malachite, NaOH·2 PbCO₃). The large range of stability of newly formed phases confirms a significant variety of E_h–pH conditions of natural weathering of matte. Jarosite is stable at pH<3, but some hydroxides and carbonates typically form in neutral and alkaline environments. Consequently, the best dumping conditions for metallurgical mattes are difficult to determine. Such materials can have severe environmental effects and should be dumped in controlled waste-disposal sites. To cite this article: V. Ettler et al., C. R. Geoscience 335 (2003).     

Study on the Cu–As–Sb–Ag–Bi–Pb–Te Sulfosalt Minerals from the Hydrothermal System of Southwestern Hokkaido,Japan

Shin‐Otoyo, Suttsu, Teine, Date, Chitose, and Koryu are sites rich in precious and base metal Miocene–Pleistocene epithermal deposits, and located in southwestern Hokkaido, Japan. The deposits are predominantly hosted by the Green Tuff Formation of Middle Miocene age. Ore petrographic study of these deposits shows the occurrence of variable quantities of Cu–As–Sb–Ag–Bi–Pb–Te sulfosalt minerals. Determination of mineralogical and chemical compositions of the sulfosalt minerals was undertaken to elucidate the time and spatial changes of the sulfide‐sulfosalt minerals. Various types of sulfosalt minerals identified from gold–silver and base metal quartz–sulfide veins represented some sulfosalt mineralization phases, such as the Cu–Fe–Sn–S phase of mawsonite and stannite; Cu–(As,Sb)–S phase of tetrahedrite–tennantite and luzonite–famatinite series minerals; (Cu,Ag)–Bi–Pb–S phase of emplectite, pavonite, friedrichite, aikinite, and lillianite–gustavite series minerals; (Ag,Cu)–(As,Sb)–S phase of proustite–pyrargyrite and pearceite–polybasite series minerals; and Bi–Te–S phase of tetradymite and kawazulite minerals. There are some trends in the paragenetic sequence of sulfosalt mineralization in southwestern Hokkaido (in complete or partial) as follows: sulfide → Cu–Fe–Sn–S → (Cu,Ag)–Bi–Pb–S → (Bi–Te–S) → Cu–(As,Sb)–S → ([Ag,Cu]–[As,Sb]–S). The formation of sulfosalt minerals is characterized by the introduction of some elements such as Sn, Bi, and Te at an earlier stage and an increase or decrease of some elements such as As and Sb, followed by the introduction of Ag at the later stage of ore mineral paragenesis sequence. Mineral composition of the Chitose and Koryu deposits are slightly different from those of Shin‐Otoyo, Suttsu, Teine, and Date due to their lack of Sn (tin) and Bi (bismuth) mineralization. The variable concentrations and relationships are not simply with redistributed trace elements from the original sulfide minerals of chalcopyrite, pyrite, galena, and sphalerite. Some heavier elements were also introduced during the replacement reaction, which is consistent with the occurrence of their associated minerals.     

山门银矿床围岩蚀变特征与成矿关系及找矿标志

山门银矿为大型独立银矿床,其围岩蚀变特别发育,先后为冷水蚀变作用和热液蚀变作用两期,冷水蚀变作用包括碎裂－红化,伊利石－水白云母化两个蚀变阶段,热液蚀变包括黄铁绢云岩化,硅化,碳酸盐化三个蚀变阶段,两期蚀变与成矿关系极为密切,在时间上具有多期和多阶段性,空间具有明显的分带性,其蚀变特征可作为寻找岩浆热液矿床的标志。     

The medium-short period tilt deformation phases character before the Zhangbei M S=6.2 earthquake and its experimental interpretation

We discussed the linear and nonlinear character of deformation anomaly before the January 10, 1998 Zhangbei earthquake based on the quantitative analysis by using the tilt observation data. And generalized the three phases character of tilt deformation. ①Before the earthquake in the scale of one year, EW tilt keeps relative stationary on the block of the northern part of Yanshan Mountain; the tilt vector recurs around a point near the epicenter; and the abrupt change appears before the imminent earthquake. ② At a geodesic point, tilts discrete level in two directions have a synchronous property with a decline tendency (that is an entropy reduction) in two years before the earthquake. ③ The anomaly intensity AF value at all geodesic points on the same crustal block appear high value anomaly at least two times within 3 years before the earthquake. Using the simulation experimental results of rock rupture, we interpreted the phenomena of tilt deformation relative stationary or other kinds of stationary (process of entropy reduction), of recurrence of tilt deformation vector, of two times AF high values, and even the earthquake in groups, etc.     

地震事件波形及震相文件抽取软件

手工收集地震数据费时费力,容易出错。利用 VB 软件开发环境,结合 Windows Socket 网络编程技术,研制地震事件波形及震相文件抽取软件,可以降低人为出错概率,减小工作量,提高测震数据的利用率。     

全球12000aBP以来火山爆发记录及对气候变化影响的评估

全新世气候变化的动力成因,至今未有定论．大量地质证据揭示了全新世气候多次降温,并反映出与火山爆发有时问对应关系．现代气候观测证明了火山灰进入平流层滞留后随环流扩散成为太阳辐射的屏障层,从而导致地表降温．停留在地质火山爆发和伞新世气候在逐个点遥相关研究上,难以从宏观机制上加以认识．本文试图对地质火山影响古气候变化的定性推论与现代火山气候效应这两个环节,给予动力机制上的联系和分析．通过火山地质记录的现代气候效应类比,对地质火山数据进行集成,所反映的五次全新世强火山爆发集中期与地质记录的寒冷期／降温期／新冰期能够对应．对火山爆发集中期和平静期两种气候状况,通过三维大气环流模式进行气候数值模拟,评估火山灰产生的不同区域的降温效应．模拟结果表明,火山灰阳伞效应造成北半球年平均温度普遍降低,且具有明显的区域差异．高纬度降温幅度大于低纬度,夏季降温幅度大于冬季．全新世火山影响气候时空记录和火山灰敏感性气候试验为进一步探讨全新世气候变化成因提供重要的科学依据,也为最终认识现代气候系统变化以及对未来十年一百年尺度的气候预测提供重要的参照系．     

塔里木盆地冷盆热改造的地震学证据

塔里木盆地是我国最大的沉积盆地,对我国油气战略选区具有较大的意义.自震旦系成盆以来,塔里木盆地表现为一个低温的冷盆.在覆盖全盆的20条地震长剖面上,识别出83处特殊的地震反射结构,其特征为同相轴向上凸起呈尖角状,形态为直立或近直立,故名地震反射尖角直立结构.共识别出四种基本类型的地震反射尖角直立结构,平缓型、正常型、巨幅型、刺穿型,两个形态基本一致的基本型紧邻而组合为双相位型,两个或多个不同类型、不同形态的集中于某处则构成复合型.平缓型、正常型、巨幅型、刺穿型依次反映了变形增强的序列,理想状态下该反射结构由深至浅存在从刺穿型至平缓型的渐变序列,故基本类型的划分只是反映某处地震反射尖角直立结构的整体形态特点.地震反射尖角直立结构部位可能发育火成岩,与盆内钻遇火成岩钻井平面分布具有较高的相关度.地幔物质上涌至岩石圈,巨大的上拱能量造成了地层的变形,叠加构造因素的改造,地震反射尖角直立结构正是这一系列作用于地震反射上的响应.地震反射尖角直立结构是"热上涌"作用的产物.有机质的成熟、油气藏的形成和破坏与盆地热作用关系密切,对照塔里木盆地已有的油气田与"尖角直立"地震反射结构的平面分布,发现二者具有较高的相关性.地震反射尖角直立结构所反映的"热上涌"现象,促进了塔里木盆地"冷盆"背景下丰富油气资源的形成.     

蒙古中南部地区地壳各向异性及其动力学意义

利用蒙古中南部地区布设的69套宽频带数字地震仪2011年8月—2013年7月记录的远震事件,使用时间域反褶积方法提取接收函数,并挑选高质量Pms震相,通过改进的剪切波分裂方法对研究区地壳各向异性参数进行了研究,最终获取了1473对各向异性参数.经过统计分析,有48个台站可以归纳出两个方向的各向异性,11台站得到单个方向的各向异性,而剩余10个台站各向异性方向比较发散.结果显示,各向异性在蒙古中南部地壳中呈不均匀分布,有54个台站得到了NE-SW向各向异性,快波偏振方向平均值为N58°E±16°,与最大水平主应力σHmax方向和区域内主要断层走向一致,说明这部分地壳各向异性的主要成因存在于上地壳,可能与流体填充的微裂隙有关.而NW-SE向各向异性在53个台站被观测到,各向异性方向变化范围平均N132°E±16°,与研究区大部分SKS分裂快波方向具有较好的一致性,说明下地壳成岩矿物晶体定向排列是各向异性的主要成因.研究区地壳各向异性的分层特征总体上支持岩石圈受到NE-SW向挤压的动力学模型.