加拿大萨斯喀彻温亚盆地某钾盐矿地质特征及其成因探讨

加拿大萨斯喀彻温亚盆地某矿区含钾盐矿层的属性母岩——草原蒸发岩具有良好的连续性,深度通常小于960m。矿石品级相对较高,K_2O舍量在9.26%~58.20%。草原蒸发岩内含有三个钾盐成矿段,分别为耐心湖(Patience Lake)含钾岩段、贝尔平原(Belle Prairie)含钾岩段、埃斯特黑齐(Esterhazy)含钾岩段。根据萨省的地球物理测井资料得出的钾盐厚度和品位数据,以及萨省政府最近发布的评估萨省钾盐资源潜力的资料,作者研究整理了萨省某区的地震、钻孔数据,预测了某区的优先勘探靶区,并对该地区的钾盐矿床地质成因做了初步探讨。     

5—6月东北冷涡持续活动及强度特征

利用1960—2012年5—6月NCEP/NCAR逐日再分析资料,基于冷涡经典定义,采取客观识别方法检索东北冷涡活动过程,根据东北冷涡活动时空变化特征给出东北冷涡持续活动过程标准, 通过冷涡强度指数进行定量化分析,该指数对冷涡持续活动过程具有较好表征意义。冷涡活动强对应5月乌拉尔山阻塞高压、贝加尔湖阻塞高压和6月鄂霍次克海阻塞高压活动频繁。通过强弱指数年合成,得到6月强指数年冷涡系统较深厚,集中于对流层中高层,冷心结构明显,具有一定大气斜压特征; 高层存在冷中心,低层有冷空气活动,中高层西风带呈明显的上游分流和下游汇合特征,分汇流之间呈东北高、西南低的偶极子阻塞形势;弱指数年冷涡系统较浅薄,主要集中在对流层中低层,冷心结构不明显,不存在阻塞形势。     

秋季南黄海浮游动物分布及其影响因素

基于2007年秋季在南黄海（32°20'~37°00'N;124°E以西）进行的浮游动物及环境因子大面调查;分析了秋季南黄海浮游动物种类组成、分布特征及其影响因素;主要结果如下:共鉴定浮游动物113种（不包括25种浮游幼体）;中华哲水蚤（Calanus sinicus）、强壮滨箭虫（Aidanosagitta crassa）、磷虾幼体（Euphausia larvae）和小齿海樽（Doliolum denticulatum）是秋季优势种;浮游动物丰度为（156.37±12.04）ind/m3;生物量为（172.57±10.41）mg/m3;与历史调查数据相比;本航次浮游动物丰度和生物量相对处于较高水平;磷虾幼体分布趋势与中华假磷虾（Psudeuphausia sinica）一致;说明秋季是中华假磷虾种群的一个重要的补充时期;小齿海樽在南黄海的大量出现系自身种群补充的结果;精致真刺水蚤（Euchaeta concinna）和肥胖软箭虫（Flaccisagitta enflata）主要分布在深水区;在近岸海区很少出现。中华哲水蚤、强壮滨箭虫丰度高值区倾向分布于海洋锋附近;进一步佐证了海洋锋对浮游动物的积聚作用。     

Size distributions and source function of sea spray aerosol over the South China Sea

The number concentrations in the radius range of 0.06 – 5 μm of aerosol particles and meteorological parameters were measured on board during a cruise in the South China Sea from August 25 to October 12, 2012. Effective fluxes in the reference height of 10 m were estimated by steady state dry deposition method based on the observed data, and the influences of different air masses on flux were discussed in this paper. The number size distribution was characterized by a bimodal mode, with the average total number concentration of(1.50 ± 0.76)×10~3 cm~(-3). The two mode radii were 0.099 μm and 0.886 μm, both of which were within the scope of accumulation mode. A typical daily average size distribution was compared with that measured in the Bay of Bengal. In the whole radius range, the number concentrations were in agreement with each other; the modes were more distinct in this study than that abtained in the Bay of Bengal. The size distribution of the fluxes was fitted with the sum of log-normal and power-law distribution. The impact of different air masses was mainly on flux magnitude, rather than the shape of spectral distribution. A semiempirical source function that is applicable in the radius range of 0.06 μmr_(80)0.3 μm with the wind speed varying from 1.00 m s~(-1) to 10.00 m s~(-1) was derived.     

基于MODIS数据的青藏高原冰川反照率时空分布及变化研究

冰川反照率对冰川融化具有重要影响,以2000-2013年MODIS的MOD10A1逐日积雪反照率数据资料为基础,分析了青藏高原冰川反照率的时空分布及变化。结果表明：冰川年平均反照率变化范围是0.42（枪勇冰川）~0.75（PT5冰川）,其中夏季平均反照率变化范围是0.45（来古冰川）~0.69（东绒布冰川和古里雅冰川）。冰川反照率空间分布并没有明显的规律性,而冰川反照率的变化速率空间分布规律明显——南部较大往北减小,北部反照率出现增大现象。研究区内大部分冰川反照率呈波动降低的趋势,年平均反照率和夏季平均反照率变化速率最大值都出现在枪勇冰川,分别是-0.015 a^-1和-0.019 a^-1。木吉和木孜塔格冰川年平均和夏季平均冰川反照率都增大,木吉冰川是由于2012年的高反照率引起的,而木孜塔格冰川主要与该地区气温降低、降水增多有关。     

The past in dust: current trends and future directions in Pleistocene geoarcheology of European loess

Loess is a main archive of Pleistocene landscapes and environments and therefore has an important connection to the preservation and interpretation of Paleolithic sites. In Europe, anthropogenic sites have been found in loess because of past local occupation. At one extreme, sites are well preserved with minimal disturbance often accompanied by embedded proxies to estimate ecological parameters. On the other hand, loess deposits have undergone post-depositional alterations such as weathering, pedogenesis or bioturbation due to changing environmental conditions or other disturbances that obscure anthropogenic sites. We outline the current state of research and connections between Paleolithic archeology and loess research while introducing a series of subsequent regional case studies as part of a special issue. We also make recommendations for future work to incorporate a wider variety of methods to create more robust inferences on hominin and environmental evolution and their connections.     

危地马拉翡翠宝石矿物学特征及其与缅甸翡翠的对比研究

危地马拉目前已成为仅次于缅甸的第二大翡翠原料供应地。这两个产地翡翠辨别的需求愈发迫切,且应用意义较大。采用显微镜观察、电子探针分析及背散射电子照相获得危地马拉蓝水料翡翠的矿物成分及结构构造特征,结合两产地翡翠产出的大地构造环境、自然地理环境、原石特征与矿物成分特征等进行对比分析。总体上,危地马拉翡翠次生原石有一定的磨圆,呈次棱角状,“皮”(风化皮)厚度较薄,较少出现翻砂现象,由“皮”向里,极少甚至几乎不存在“红雾”。相对地,缅甸翡翠次生原石发育显著的球状风化,原石通常有较好的磨圆度,棱角状不明显,“皮”厚度可达数厘米,用手压磨有显著的翻砂现象, “皮”“肉”之间偶可见“红雾”。硬玉与绿辉石成分判别图显示危地马拉翡翠中硬玉和绿辉石呈相对富Ca、贫Na的特征,而缅甸翡翠中硬玉和绿辉石整体呈相对贫Ca、富Na的特征。在Fe含量上,危地马拉翡翠中硬玉的Fe含量较缅甸翡翠中硬玉的Fe含量偏低,而危地马拉翡翠中绿辉石的Fe含量较缅甸翡翠中绿辉石的Fe含量偏高。对翡翠外观特征的充分对比和对判别图的综合分析可应用于实际中翡翠产地的区分。     

新疆若羌县红柳沟Ⅰ号剖面新元古界成冰系冰沟南组硅质岩特征与沉积环境*

新疆若羌县红柳沟Ⅰ号剖面出露厚约300 m的新元古界成冰系冰沟南组的细粒沉积物和碳酸盐岩等,并发现有沥青油气显示。通过厚160 m左右硅质岩剖面实测以及岩石学、地球化学等研究表明: 红柳沟Ⅰ号剖面中的硅质岩主要由石英、黏土构成,有微量的含铁、锰、磷的独立矿物;具有隐晶质、微晶石英和粗-巨晶石英“镶嵌结构”3种结构类型;硅质岩中SiO₂、Fe₂O₃、Ba和δEu_n值相对较高,Al₂O₃、MnO、MnO/TiO₂、U/Th和Sr/Ba值较低,∑REE、Sr/Ba、MnO₂/TiO₂和δCe_n值等呈现有规律的变化;δ³⁰Si值平均为-0.43‰(-0.8‰~0.3‰),$\delta^{18}O_{Snow}$值平均为20.42‰(16.0‰~26.0‰),估算的平均温度为90 ℃(52~127 ℃),指示了硅质岩具有多个沉积旋回,在海水与热水参与的大陆边缘盆地中沉积,并经历了早成岩期、浅埋藏期以及与多期走滑断裂活动有关的热流体与大气淡水的叠加改造。     

Homogeneity and mechanical behaviors of sands improved by a temperature-controlled one-phase MICP method

Acta Geotechnica - Microbially induced carbonate precipitation (MICP) has been actively investigated as a promising method to improve soil properties. A burning issue impeding its wide application...