Sedimentary Characteristics of the Cretaceous in the Songliao Basin

The rupture of the lithosphere in Late Jurassic brought about the eruption of basaltic magma in the Songliao Basin. The evolution of the basin in Cretaceous progressed through six stages: pre-rift doming, extensional fracturing, fault subsidence, fault downwarping, downwarping and shringkage, resulting in the deposition of terrstrial facies nearly 10,000 m thick. There are different depositional sequences in these stages: the depositional period of the Early Cretaceous Shahezi and Yincheng Formations is the development stage of the down-faulted basin, forming a volcanic rock-alluvial fan-fan delta-lacustrine (intercalated with episodic turbidites)-swamp facies sequences; the period of the Early Cretaceous Dengluku Formation is the transformation stage of fault subsidence into fault downwarping of the basin, forming a sequence mainly of alluvial plain-lacustrine facies; the depositional period of the Early Cretaceous Quantou Formation-Late Cretaceous Nenjiang Formation is the downwarping stage of the basin, forming an alluvial plain-delta-lacustrine facies sequence; the period of the Late Cretaceous Sifangtai Formation-Mingshui Formation is the shringkage stage of the basin, forming again a sequence mainly of alluvial plain-alluvial fan and small relict lacustrine facies. These vertical depositional sequences fully display the sedimentary characteristics of a failed continental rift basin. Many facts indicate that the two large-scale lake invasions, synchronous with the global rise of sea level, which took place in the downwarping stage of the basin development, led to the connection between the lake and sea.     

论鸟类飞行的起源

笔者简要介绍了有关鸟类飞行起源的两种假说,即“飞行的树栖起源”假说和“飞行的奔跑起源”假说,并根据近几年中国辽西发现的化石材料,对两种假说的立论依据和机理进行了分析和评述,初步认为两种可能性均存在,但因奔跑而飞地的机制更为普遍合理,“上树”是一种可能的条件,但既非必要条件也非充分条件。     

Cephalopods of the “Falang Formation” (Triassic) from Guanling and Zhenfeng Counties, Guizhou Province, China

The "Falang Formation" of western Guizhou was previously called the "Halobia Bed" and considered to be I .adinian in age. It was subdivided upward into the Zhuganpo, Laishike and Longchang members based on ammonites and the Trachyceras multitubertulatum Zone of the Longchang Member was put in the Lower Carnian. Here in the present paper, 4 genera and 9 species of ammonites and 1 nautiloid genus and species collected from the upper part of the "Falang Formation" (i.e. the Wayao Formation used in this paper, equivalent to the Laishike Member from Guanling and Zhenfeng counties are described. The geological and geographical distribution of these cephalopods, as well as the co-existing conodonts, put the Wayao Formation to the late early Carnmian.     

薄互层地区高品质地震资料采集影响因素试验研究

根据薄互层地区地质特点,以及所要达到的分辨率的要求,确定了所要保护的主频频率和施工参数。针对影响分辨率的因素,在激发时使用小药量和“钻杆扫描”的方法选择激发深度;在接收时使用中高频检波器、小组合和检波器下井接收的方法,并对它们进行逐一论证,取得了较好的效果。     

Atmospheric nitrous oxide observations above the oceanic surface during the first Chinese Arctic Research Expedition

339 gas samples above oceanic surface were collected on the cruise of "Xuelong" expeditionary ship and nitrous oxide concentrations were analyzed in the laboratory. Results showed that Atmospheric average N2O concentration was 309 ±3. 8nL/L above the surface of northern Pacific and Arctic ocean. N2O concentrations were significantly different on the northbound and southbound track in the range of the same latitude, 308.0 ±3.5 nL/L from Shanghai harbor to the Arctic and 311.9 ±2.5 nL/L from the Arctic to Shanghai harbor. N2O concentration had a greater changing magnitude on the mid- and high-latitude oceanic surface of northern Pacific Ocean than in the other latitudinal ranges. The correlation between the concentrations of the compositions in the aerosol samples and atmospheric N2 O showed that continental sources had a great contribution on atmospheric N2 O concentration above the oceanic surface. Atmospheric N2O concentration significantly increased when the expeditionary ship approached Shanghai h     

小浪底库区庙上北滑坡滑带土粘土矿物定向性的X射线衍射研究及其对滑坡的作用

根据小浪底库区庙上北滑坡滑带土粘土矿物的X射线衍射结果，进行定向性定量分析计算，得出滑带土粘土矿物颗粒的定向度为弱到中等定向，并以中等定向为主。因而在水的往返作用下，滑带土具一定的胀缩性及胀缩的不均匀性，再加上粘土矿物本身亦具有的胀缩性及胀缩的可逆性和循环性，故导致滑带土抗剪强度和结构强度不断降低，大大影响斜坡的稳定性。     

铂矿标准物质的核分析方法研究

针对铂矿标样基体中高铜、高镍、高硫等特点．对常规的镍锍试金预处理中子活化分析流程作了适当改进，包括铂矿样品的灼烧、调节试金配方、改变酸溶条件和仪器测试条件。流程中铂族元素的回收率均在86％以上。用南非的铂矿标准物质SARM7和我国的铜镍硫化物铂族元素标准物质975作了对照分析,结果与标准值相符。表明改进后的流程适用于同类含铂铜镍矿样品中铂族元素的测试。     

杂卤石溶解性能的测定

通过测定25℃，50℃，75℃时液相K^ ，Ca^2 ，Mg^2 ，SO4^2-等组成浓度随时间的变化，考察杂卤石在水中的溶解行为，测试得25℃，50℃，75℃条件下杂卤石中K^ 在水中的平衡浓度分别为19．13，21．29，36．77(mg／m1)。K^ 溶解平衡浓度随着温度的升高而增大。实验研究25℃条件下杂卤石在CaCl2溶液中的溶解行为。在5％和10％CaCl2溶液中K^ 的平衡浓度分别为25．65，35．24(mg／m1)。明显大于在水中的平衡浓度。表明CaCl2对杂卤石具有明显的增溶作用，可作为杂卤石的良好溶浸剂。实验结果对不溶性或难溶性的钾矿资源的开发利用具有理论参考和实际应用价值。     

神农架松柏镇水文地球化学研究

近年来，神农架松柏镇居民的结石病时有发生．并有增长的势头。为了解地质环境尤其是饮用水对病患的影响，笔者现场对患病情况以及各种水源(包括河水、泉水、自来水)的来源、化学组成和放射性进行了调查，运用水质常规方法和原子吸收光谱分别测定了离子和微量元素。同时，与地质环境类似的木鱼镇进行了对比调查。研究结果显示，两地地表水、地下水的各种指标均未超出“生活饮用水水源水质卫生标准”。(CJ3020-93)，且松柏镇水体中的放射性(γ射线)低于木鱼镇，而居民的患病率却远高于木鱼镇，可见松柏镇的水环境与居民的结石病无直接关系。     

泥炭沼泽有机地球化学研究进展

近几十年来，国内外泥炭沼泽地球化学研究取得了一系列重要进展，特别是在脂类化合物和稳定同位素等方面。泥炭沼泽是一个良好的地质档案，泥炭纤维素碳、氢和氧同位素组成和比值是环境变化的综合参数，沉积脂类化合物含有反映有机质母源先质的骨架结构，这些标志物高分辨率地记录了全新世以来古气候、古植被和古环境的演变信息，在当今全球变化研究中占有相当重要的地位。本文综述了泥炭沼泽地球化学研究进展，侧重于泥炭沼泽脂类化合物和稳定同位素等标志物的地球化学研究现状和发展趋势；侧重论述了研究技术的发展、定性说明到定量分析的过渡、研究精度的提高及存在的问题，分析了这些分子标志物与植被演替、气候变迁和环境变化间的对应关系，指出了我国在该方面的薄弱之处以及需加强的领域。