Seasonal Stratification Characteristics of Vertical Profiles of Water Body in Lake Lugu

For the purpose of exploring seasonal stratification characteristics of water hydrochemistry, the seasonal dynamics and vertical thermal stratification of water temperature in Lake Lugu, the vertical profiles of water temperature (Temp), Electrical Conductivity (EC), Dissolved Oxygen (DO), pH and Chlorophyll-a (Chl-a) of Lake Lugu were monitored in January, April, July and October 2015, respectively. The results indicated that water body of Lake Lugu appeared thermal stratification in spring, summer and autumn, however, in winter, the water temperature in vertical direction was homogeneous. The thermocline was located between 10 and 25 m, nevertheless, it moved down to range from 20 to 30 m in autumn. In addition, water temperature in hypolimnion was maintained almost as a constant and consistent with annual temperature, indicating water body was stable all along. The results showed that the thermal stratification had some influences on vertical distributions of DO, EC, pH and Chl-a. The significant stratification of DO, EC and pH was found, especially in summer, DO and pH values in thermocline peaked due to greatly stable thermal stratification and temperature increase. In hypolimnion, DO concentration and pH value were very small. Moreover, Chl-a concentration was higher in the surface and lower in the bottom water, implying that human should be highly alter to prevent the emergence of a large area of algae in Lake Lugu. EC took on decreasing variation, besides, lower in the thermocline. While,Lugu Lake water salinity was lower and substantially constant (~ 0.10‰), without considering the effects of salinity, both in vertical sections and in epilimnion, thermocline and hypolimnion, there all existed a simple linear function of the relationship between EC andwater temperature, showing that Lugu Lake was affected by natural climate and keeps natural state.     

右江盆地三叠纪岩层极低级变质作用及地球动力学意义

右江盆地三叠纪槽盆相浊流沉积岩系遭受过区域极低级变质作用。依据地质观察和伊利石结晶度、绿泥石-云母堆垛集合体、标志性粘土矿物及白云母(伊利石)b0参数测定资料,阐述了泥质岩石的成岩变质作用经浅层(近)变质作用到浅变质作用的转换特征。变质温度区间为150-350℃,低压类型,具高地温梯度(40-43℃/km).变质级及亚带总体与地层时代及岩层在地层柱中的位置有耦合关系,而与区域变形强度无关。最后指出区域极低级变质作用是印支-燕山构造旋回早期及区域变形前的地质事件,属于地壳伸展构造背景下右江边缘型盆地内部的埋藏型变质作用。     

鄂西早三叠世南漳-远安动物群地层分布特征

在区域地质调查的基础上,以远安张家湾嘉陵江组剖面为重点,通过对南漳和远安交界地区下三叠统嘉陵江组剖面测制和多处化石点考察,重新厘定研究区内嘉陵江组岩性特征.认为研究区内的嘉陵江组划分为3个岩性段更为合理,产南漳-远安动物群的纹层状灰岩段位于二段顶部.通过系统化石发掘和张家湾剖面详细描述,初步查明了南漳-远安动物群的垂向...     

珠江广州河段重污染沉积物中多环芳烃赋存状态初步研究

对珠江广州河段重污染沉积物进行粒度分级 (>500 μm、500～ 220 μm、220～ 63 μm、63～ 22 μm和 < 22 μm),每个粒级的样品进行重液分离,收集轻组分 (有机质 )和重组分 (主要为无机矿物及无定型有机质 ).在显微镜下对沉积物中不同粒径轻重组分的吸附剂进行鉴定,对其中的多环芳烃进行定量分析,结果表明,白鹅潭样品中有机质占总质量的 9.10%,富集了 81.55%的多环芳烃,无机矿物和无定型有机质占 90.92%,富集了 18.45%的多环芳烃;黄埔样品中有机质占总质量的 8.95%,富集了 56.50%的多环芳烃,无机矿物和无定型有机质占 91.15%,富集了 43.50%的多环芳烃.轻组分中的有机吸附剂对多环芳烃的富集能力比重组分无机矿物和无定型有机质高 1～ 2个数量级,轻组分有机吸附剂中焦碳和碳黑富集能力较高,植物碎屑较低.总有机碳和碳黑的含量与多环芳烃的富集能力没有明显的相关性.     

Volcanism at the Permian-Triassic Boundary in South China and Its Effects on Mass Extinction

This paper discusses the clayrocks widespread at the Permian-Triassic boundary, which are mostly of volcanic origin. Volcanogenetic textures, structures and minerals such as high-temperature quartz are found in clayrocks at the Permian-Triassic boundary in many places. Thousands of microspherules have been collected from the Boundary clayrocks, many of which exhibit the typical features of the process from melting to cooling and solidification. indicating that they were formed by volcanic eruption or extraterrestrial impact. Volcanic effects on the Permian-Triassic mass extinction may be reflected in conodonts, algae and ammonoids. The Boundary clayrocks are found in many Permian-Triassic sections along the coast of Tethys. Their orighin remains to be studied.     

Identifying sources and hazardous risks of heavy metals in topsoils of rapidly urbanizing East China

With rapid economic and social development, soil contamination arising from heavy metals has become a serious problem in many parts of China. We collected a total of 445 samples (0–20 cm) at the nodes of a 2 km×2 km grid in surface soils of Rizhao city, and analyzed sources and risk pattern of 10 heavy metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn). The combination of Multivariate statistics analysis and Geostatistical methods was applied to identify the sources and hazardous risk of heavy metals in soils. The result indicated that Cr, Ni, Co, Mn, Cu, and As were mainly controlled by parent materials and came from natural sources. Cd and Hg originated from anthropogenic sources. Pb and Zn, belonging to different groups in multivariate analysis, were associated with joint effect of parent materials and human inputs. Ordinary Kriging and Indicator Kriging suggested that single element and elements association from the same principal components had similar spatial distribution. Through comprehensive assessment on all elements, we also found the high risk areas were located in the populated urban areas and western study area, which could be attributed to the higher geological background in the western part and strong human interference in the eastern part.     

济阳坳陷东部长堤走滑断裂带构造特征及演化过程

济阳坳陷东部长堤断裂是一条特征明显的走滑断裂带,以T2地震反射层（沙河街组二段底面反射层）为界,发育深层次和浅层次两套断裂系统。深层次断裂系统为长堤走滑断裂带的主体,发育R-P断层组合,剖面上呈丝带状构造样式,平面上呈发辫状构造样式;浅层次断裂系统由一组近南北向左阶羽状雁列带组成,雁列带中的每条断层为近南北向走滑断裂的T断层。Es3-Es2下期,长堤走滑断裂带开始活动,发育深层次断裂系统,系由济阳坳陷和渤中坳陷之间的构造调节作用所造成;Es上2-Ed期,发育浅层次断裂系统,与长堤深层次断裂持续活动以及沉积盖层的逐渐增厚有关,同时,郯庐断裂带开始对研究区的构造格局产生影响;Ng-Nm期,研究区处在巨大的北东向走滑递进应变带中,长堤近南北向走滑断裂带让位于郯庐断裂带控制的北东向走滑体系。     

成都金沙遗址区全新统震积岩的发现及其地质意义

震积岩是灾变性事件岩的典型代表,是具有震积构造和震积岩序列有一定成因联系的一组岩石的总称。成都金沙遗址区全新统地层中首次发现震积岩,该地层自下而上为底部砾石层、中部暗色(含炭)泥质层、上部褐黄色土壤层,整体属河流冲积物。通过野外观察,研究区发育一组走向SE120°的正断层,断层两盘的底部砾石层顶界面有明显的错断。构成地垒构造;在IT6511、IT6610层位中的断层带中见明显阶梯状断裂,其以张性正断层为主,断距约为10~90cm。在靠近阶梯状断裂的IT6512、IT6613-6614层位中发现一系列地震成因的软沉积物变形标志及破裂构造,包括砂土液化(脉)、液化卷曲变形构造、负载构造、微断裂、地裂缝、震塌岩等。分析认为这些软沉积物变形标志及破裂构造是由同期地壳活动引起的地震作用形成的。金沙遗址区震积岩的发现,对研究四川盆地全新世以来的古环境有重要意义。     

山东省一次冰雹云过程的数值模拟

利用中国气象科学研究院的三维对流云模式,对发生在山东省的一次强降雹天气过程进行了数值模拟,并将模拟结果与雷达观测资料进行了检验.分析了风暴各发展阶段的流场结构和回波结构特征及微观物理量的分布及其演变.结果表明:雹胚源区出现在主上升气流前侧上升气流向辐散下沉气流的转向处,在垂直方向上位于最大上升速度上方;冰晶碰并过冷水形成霰和冰雹,冰雹粒子在气流循环处生长.研究结果对实际防雹业务有一定参考意义.     

1954—2004年珠江三角洲大气能见度变化趋势

利用珠江三角洲5个城市气象观测站 (广州、深圳、台山、惠州、高要) 的长期能见度观测资料, 采用累积百分率、Ridit分析法和烟幕/霾日频率3种统计分析方法, 分析了1954—2004年珠江三角洲能见度变化趋势, 初步探讨了珠江三角洲大气环境的变化特征及其可能原因。结果表明:近50年来, 珠江三角洲城市能见度呈显著下降趋势。能见度的下降起始于20世纪70年代初, 并在经济高速发展的80—90年代初进一步恶化, 90年代中期之后虽然能见度变化趋于平缓, 但能见度下降的趋势仍未从根本上改变。珠江三角洲能见度与当地的人口增加和经济发展程度有密切的关系, 同时污染物的区域输送对西部下风向城市能见度也有很大影响。珠江三角洲能见度未得到有效改善的主要原因, 很可能是由于细粒子污染, 尤其是二次粒子前体物如SO2和NOX等的排放未得到有效控制。