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101.
塔里木盆地西部古岩盐地质地球化学特征与成钾条件分析 总被引:11,自引:1,他引:11
塔里木盆地是我国重要的成盐盆地,为我国最有远景的找古钾矿地区之一。本文通过多年野外实地调查和大量岩盐样品的化学分析,特别是岩盐中可以指示沉积阶段的Br×103/Cl系数等区域分布特征,联系前人研究资料,分别从构造环境、地层和岩相古地理、地球化学特征等方面进行了成钾条件分析。结果表明,莎车盆地西部喀什坳陷和库车盆地中部拜城坳陷宏观地质特征均有利于钾盐沉积;岩盐地球化学组成相对于正常海相沉积表现出明显的贫Br特征,属海陆交互相或海源陆相沉积。相比之下,莎车盆地的喀什次级坳陷是目前最有前景的找钾远景区。 相似文献
102.
楚雄盆地晚三叠世为一建立在扬子板块西缘前寒武纪基底之上的海相—海陆过渡相—陆相沉积盆地。中三叠世拉丁期—晚三叠世卡尼期沉积了一套深水的灰色薄层状粉砂质泥岩和泥质粉砂岩;诺利期早期以华坪隆起为界有两个沉降中心,华坪隆起以西的推覆体之上为广海陆架相的细碎屑岩沉积、远源浊积岩,以东为局限环境下的细碎屑岩沉积夹浊积岩;诺利期晚期为大规模的三角洲前缘砂体组成下超的复合体,古地理格局继续保持东西向分带,呈对称分布,盆地西部为陆相、海陆过渡相,盆地中部为海相沉积。瑞替期在原形盆地中形成舍资组的河流—滨岸沉积,在推覆体上形成白土田组的冲洪积物。总之,表现古地理变迁为一个由西东逐渐超覆、由下向上粒度逐渐变粗、由海相变为陆相的过程。 相似文献
103.
104.
ZHAO Pengda 《中国地质大学学报(英文版)》2004,15(3):245-252
“Three-component” method consists of three clase-connected aspects: geological anomaly,diversity of mineralization and mineral deposit spectrum. All these three concepts are not new separately, but it is a new approach to combine these three aspects in one single concept for quantitative mineral resources prediction and assessment and it is also the first time to conduct a more detailed study in each aspect. Investigation and clarification of geological anomalies, diversity of mineralization and spectrum of mineral deposits are realized by digitization and quantification of ore forming controlling factors, oreexisting symbols or marks, characteristics of mineralization and regulation of ore-genesis and laws of distribution. These procedures lead to construction of a “digital model“ for mineral resources prediction andassessment. 相似文献
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106.
提出了符合OpenGIS规范的二维地理信息系统组件软件MapManager的设计思想 ,介绍了MapManager的设计过程 ,并对其不足和进一步研究方向进行了讨论。 相似文献
107.
The aim of the study was to assess the environment-health development in different regions of China. 175 indicators, such as average life expectancy at birth, emission intensity of waste gas, GDP etc. were chosen to describe various aspects of the environment, health and development of China. Of all the indicators, life expectancy can sufficiently reflect health situation of population. Consequently, life expectancy was identified as key indicator, and 42 out of 175 indicators were selected for establishing the environment-health indicator framework with three grades of integrative indices to assess the development of environment-health of China. Based on the hierarchical relation between various grades of indices, the comprehensive environment-health index was calculated and contributed to classify the environment-health situation of 30 provinces, municipalities and autonomous regions in China which were divided into five grades by four predefined limits. Comprehensive assessment indicates that the environment-health situation of the eastern and coastal areas is superior to that of inland which is the western regions with underdeveloped economy and rigorous natural condition. Especially, the Qinghai-Tibet and Yunnan-Guizhou plateaus in southwestern China are most vulnerable in the environment and population health. These fit in with the pattern of national socio-economic development, which fully shows that socio-economic context plays a dominant role in the improvement of environment-health in China. 相似文献
108.
High buildings or architectural complex in urban areas remarkably distort the urban surface wind fields. As the air flow approaches,local strong wind may appear around the buildings. The strong wind makes the pedestrians on sidewalks, entrances and terrace very uncomfortable and causes the pedestrian level wind environment problem. In this studies, hot-wire wind measurement, wind scouring in wind tunnel and numerical computation were carried out to evaluate the wind environment of tall buildings in the prevailing flow conditions in Beijing areas. The results obtained by three techniques were compared and mutually verified. The conclusions drawn from three approaches agree with each other. Also the advantages and limitations of each method were analyzed. It is suggested that the combination of different techniques may produce better assessment of wind environment around high buildings. 相似文献
109.
Late Quaternary systematic stream offsets caused by repeated large seismic events along the Kunlun fault, northern Tibet 总被引:8,自引:0,他引:8
The Kunlun fault is one of the largest strike-slip faults in northern Tibet, China. In this paper, we focus upon the Kusai Lake–Kunlun Pass segment of the fault to understand the geomorphic development of offset streams caused by repeated large seismic events, based on tectono-geomorphic analysis of high-resolution satellite remote sensing images combined with field studies. The results indicate that systematic left-lateral stream offsets appear at various scales across the fault zone: Lateral offsets of small gullies caused by the 2001 Mw 7.8 Kunlun earthquake vary typically from 3 m to 6 m, meanwhile streams with cumulative offsets of 10 m, 25–30 m, 50–70 m, 250–300 m and 750–1400 m have resulted from repeated large seismic events during the late Quaternary. An average slip rate of 10 ± 1 mm/year has been estimated from the lateral stream offsets and 14C ages of alluvial fan surfaces incised by the streams. A three-dimensional model showing tectono-geomorphic features along a left-lateral strike-slip fault is also presented. The Kusai Lake–Kunlun Pass segment provides an opportunity to understand the relationship between geomorphic features produced by individual large seismic events and long-term geomorphic development caused by repeated large seismic events along a major strike-slip fault. 相似文献
110.
塔里木盆地西部古盐岩同位素地球化学与成钾预测研究 总被引:5,自引:0,他引:5
我国钾盐资源紧缺,寻找优质大型钾盐矿床一直是国家资源普查的重要目标这一。塔里木盆地在其地史发展过程中,曾与广海相通,多期海水的侵入和间断,以及适宜的构造、古地里环境具备成钾的基本地质条件,因此一直被列为我国寻找古钾矿的重点地区。为了更准备地判断其成盐的海陆相特征,即成盐物质的主要来源,以及岩盐沉积之前的古卤水蒸发浓缩阶段,预测更有前景的成钾远景区,论文选择了蒸发岩沉积序列中的石膏及石盐矿物,分别分析了其硫同位素及氯同位素分布特征。结果表明,非还原环境下沉积的石膏硫同位素可以准确判断盐岩沉积的海相、陆相和海陆交互沉积特征,氯同位素可以判断岩盐的沉积阶段。应用这两个同位素新指标分析,塔里木盆地西部喀什次级构造凹陷晚白垩世盐岩沉积接近海相沉积类型,而且岩盐沉积阶段较晚,是一最有利成钾远景区。 相似文献