印尼西部库泰盆地沉积演化与油气勘探潜力分析

为明确库泰盆地充填演化历史与勘探方向,从库泰盆地构造演化分析出发,在明确构造演化对盆地沉积充填控制作用基础上,分析了盆地烃源岩分布和沉积演化特征,探讨了盆地油气勘探方向。研究结果如下:(1)盆地演化经历了3个构造演化阶段,断陷期(始新世)、坳陷期(渐新世-早中新世)、反转期(中中新世之后),并以中新世末为界进一步划分为快速沉积期和剥蚀改造期;(2)陆上始新统烃源岩局部发育,不发育中新统烃源岩;海上发育中新统三角洲煤系烃源岩,具有较强的生烃能力,两套烃源岩分布不同,导致海陆油气发现的差异性;(3)陆上生烃能力有限,超深水区风险较大,有利区位于中新统烃源灶60 km范围内,有利区带内中中新统-上新统岩性圈闭是勘探的潜力目标。     

The complex nonlinear systems with fractal as well as chaotic dynamics of annual runoff processes in the three headwaters of the Tarim River

This paper attempted to identify fractal and chaotic characteristics of the annual runoff processes in headwaters of the Tarim River. Methods of fractal analyses were used to explore several aspects of the temporal changes from 1957 to 2002. The main findings are as follows: (1) The annual runoff processes of the three headwaters of the Tarim River are complex nonlinear systems with fractal as well as chaotic dynamics. (2) The correlation dimensions of attractor derived from the time series of the annual runoff for the Hotan, Yarkand and Aksu rivers are all greater than 3.0 and non-integral, implying that all three rivers are chaotic dynamical systems that are sensitive to initial conditions, and the dynamic modeling of their annual runoff process requires at least four independent variables. (3) The time series of annual runoff in each river presents a long-term correlation characteristic. The Hurst exponent for the period of 1989 to 2002 suggests that we may expect to see an increasing trend in the annual runoff of the Aksu and Yarkand rivers in the years after 2002, but a decreasing tendency for the Hotan River in the same period.     

闽江流域水体氨氮降解系数实验模拟研究

本研究采用模拟实验对闽江流域氨氮的降解规律进行研究,降解系数采用稳态一维降解模型进行分析计算,闽江上游流域氨氮的平均降解系数为0.140~0.260 d-1,中下游流域氨氮的平均降解系数为0.099~0.203 d-1。结果表明,闽江上游流域氨氮自净能力比中下游流域的自净能力好,古田溪断面的氨氮平均降解系数低于全国的平均值,说明氨氮自净能力相对较弱,本研究为确定流域水环境容量和纳污能力及制定污染物总量控制提供科学依据。     

Correlation of T-log with E-log in coal-bearing formations

The profile of temperature gradient versus depth (T-log) has been found to be very useful for correlation with electrical resistivity log (E-log) in coal-bearing formations. A positive correlation between electrical resistivity and thermal resistivity is observed in coal sections whereas a negative correlation is found in sandstone/shale beds, thus helping in coal prospect evaluation. T logs have been used to correct the location of coal bed which had apparently been misinterpreted by the E-log. Hole to hole correlation of T-log and E-log is found to be excellent and it is observed that thermal resistivity characteristics of given formations remain fairly uniform. A rough estimation of coal grade is possible from the detailed study of the T-logs. Abrupt changes of temperature gradient as also its reversals have been observed in burnt coal sections.     

伊犁盆地北部山麓黄土粒度端元指示的粉尘堆积过程

中亚干旱区是全球重要的粉尘源区,是全球变化与区域响应研究的关键区域之一。中亚粉尘形成搬运沉积过程一直是全球变化研究的热点科学问题。本文选取位于伊犁盆地北部、北天山南麓不同地形和气候条件下的两处黄土剖面,对其沉积速率最高的层段进行了粒度测试分析,结合聚类分析和粒度分布曲线拟合两种方法,重建了黄土粉尘的堆积过程。伊犁盆地黄土主要由远源和近源物质组成,分别由高空西风和中尺度的区域风搬运而来。高空西风所携带的远源粘粒级矿物颗粒对盆地东部降雨较高地区有一定的贡献,而在盆地西部不容易沉降下来。中尺度区域风所搬运的近源物质组成了黄土沉积物的主体,而近源区沉积物的可用性在黄土的形成过程中扮演着重要角色。另外,非风暴过程中(沙尘暴过后)出现的浮尘在沙尘暴天气频率减少的时期对黄土的发育有重要贡献,而在沙尘暴天气频发的时期,较差的植被覆盖度能够使得已经沉降下来的浮尘组分重新被扬起至大气中。由此建立了一个粉尘堆积的概念模型。认识黄土粉尘的堆积过程对现代沙尘天气的治理和人类生存环境的改善具有重要作用。     

青海达布逊湖50万年以来气候变化的孢粉学证据

基于青海柴达木盆地达布逊湖达 1井岩芯样品孢粉分析结果,将孢粉谱划分为Q₂ 、Q₃ 和Q₄ 三个孢粉带;并根据孢粉组合特征讨论了过去 5 0万年中研究区植被演化和古气候变化问题。达 1井沉积剖面年龄根据古地磁测定。研究结果表明,柴达木盆地中更新世中、晚期 ( 5 0 0～ 130kaBP)气候可能为暖温带半潮湿型,晚更新世 ( 130～ 10kaBP)气候为温带半干燥型,全新世 ( 10～ 0kaBP)气候为寒温带干燥型。晚更新世气候变化与青藏高原古里雅冰芯所记录的冷暖事件演变基本一致.     

新疆和田河流域柽柳沙堆的生物地貌发育过程

Tamarix nabkha is one of the most widespread nabkhas,distributing in the arid region of China.Based on the observations outdoors and the simulation experiments in laboratories,analysis in this paper refers to the biological geomorphologic features and growth process of Tamarix nabkhas in the middle and lower reaches of the Hotan River,Xin- jiang.And the results indicate that the ecological type of Tamarix in the study area is a kind of Tugaic soil habitat based on the deep soil of the Populus Diversifolia f...     

Relationship between surface pollen assemblages and vegetation in Luonan Basin,Eastern Qinling Mountains,Central China

The catchment of South Luohe River in Central China is an important region for investigating modern pollen-environment relationship, because it is located in the transitional zone between south and north China, an environment which is sensitive to climate changes. In this study, 40 surface samples under ten vegetation types were collected to reveal the relationship between pollen assemblages and vegetation. The results show that the surface pollen assemblages reflect the vegetation quite well. In forest topsoils, the average of arboreal pollen content is greater than 40%, and the Selaginella sinensis spore is high. As to sparse forest grassland and shrub community, the average arboreal pollen is 13.2% and 16.6% respectively, and the shrub pollen is relatively higher than that of grassland samples. The grassland and farmland are characterized by low percentage of tree and shrub pollen (<10% and <1%), and high percentage of herbs (>80%). Pinus, Quercus and some other arboreal pollen can indicate the regional vegetation because of their dispersal ability. Quercus pollen is under-representative and so is Pinus. Artemisia pollen is significantly over-represented, has poor correlation with the plant coverage, and may reflect human disturbance. Gramineae can indicate plant quite well, but with low representation. High content of Chenopodiaceae probably suggests human impact. Predominant Selaginella sinensis can be used as an indicator of forest environment. Cluster analysis and principal components analysis of pollen assemblages can distinguish forest and non-forest vegetation well. The former method is better at separating pine and mixed forests, while the latter is more stable and could better differentiate farmland and other non-forest area. The first axis of PCA mainly reflects the humidity.     

柴达木盆地察尔汗湖相沉积物的粒度分布模式及其环境意义

对柴达木盆地察尔汗地区ISL1A孔的湖相沉积物样品进行了粒度分布特征分析,研究表明：（1）样品的粒度特征呈三峰模式,部分高盐阶段样品缺失第三峰,为双峰模式;（2）2～10 μm部分以湖成组份为主;10～70 μm和70～650 μm部分以风成组份为主;（3）<2 μm的组份可能与湖泊的生物化学成因有关。上述各组份与气候变化密切相关,且各自代表的环境意义也不同：<2 μm和2～10 μm部分反映了湖泊淡化-咸化程度和水量变化过程。10～70 μm部分可能在一定程度上反映了东亚冬季风的强度;70～650 μm部分反映了尘暴天气的程度。环境指标的对比分析很好地验证了ISL1A孔样品粒度各个组份划分的准确性,并可反演92.9 ka以来该地区的古气候演化过程。     

新疆和田河流域土地利用/覆被变化及其驱动力分析

土地利用／覆盖变化及其驱动力分析是土地利用／覆盖研究的一个主要核心内容。利用1990年、1999年和2005年和田河流域3期土地利用数据,对和田河流域1990—2005年土地利用/覆被变化进行了定量的分析研究,同时利用相关分析和主成分分析探讨了土地利用/覆被变化的驱动力。研究结果表明:在15 a尺度上研究区土地利用/覆被变化总特征是耕地、林地、水域和建设用地面积增加,草地和未利用地面积减少;土地利用程度变化量为0.56%,流域土地利用处于发展时期;优势度没有发生明显的变化,未利用地一直最高。研究区土地利用/覆被变化的主要驱动力为人口因素、经济因素、富裕程度、政策因素、技术因素和水文因素等,各驱动因素以合力形式作用于土地利用/覆被使其变化,其中,人口因素在土地利用/覆被变化中起主导作用。