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新疆塔里木地块北缘碱性岩(矿)带的地质构造环境 总被引：1，自引：0，他引：1
塔里木地块北缘碱性岩矿带位于哈萨克斯坦板块南缘和塔里木板块会聚的天山造山带中。碱性杂岩和矿产明显受深断裂控制,由北而南划分为活动陆缘深断裂、板边深断裂和板内深断裂三种不同构造类型。 相似文献
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Mineral Composition of Loess—Paleosol Samples from the Loess Plateau of China and Its Environmental Significance 总被引：1，自引：0，他引：1
34samples of loess-paleosol from the Luochuan and Xifeng sections in the Loess Plateau,northern China were eparated into sand,silt and clay fractions and analyzed for their mineral compositions.The results indicate that there is almost no difference between loess and paleosol in mineral composition.Major mineral species are quartz,mica,feldspar and chlorite,accounting for about 88-92% of the total;other minerals are kandite,smectite,vermiculite and a few heavy minerals.The calcite,magnetite and hematite were not taken into consideration because of their removal in the process of sample preparation.The main difference with respect to the mineral composition of samples collected from different sections and different statigraphic levels lies in the amount and grain size of minerals hosted.Comparisons between the Luochuan section and the Xifeng section,between paleosol and loess and between the upper part and the lower part of some paleosol layers show that the formers contain less feldspar but more mica and vermiculite and are finer in grain size,indicating the co-occurrence of both biochemical weathering process responsible for mineral change and physical weathering process leading to grain-size change during the soil-forming processes.This result favours such an explanation of the soil-forming mechanism that loess deposition and paleosol development occurred synchronously,though the rate of soil formation was greater than that of loess deposition,thus leading to soil development. 相似文献
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成矿作用演化与地壳演化密切相关。成矿作用不仅在空间分布上有规律，而且还具有形成上的深成性。成矿作用在一定的空间发生、发展和演化，因而具有大地构造指示意义。根据大地构造环境标志可以预测所要寻找的矿床类型和种类。文章例举了斑岩矿床浅成热液金矿床铅锌矿床及铬铁矿床。 相似文献
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李斌 《华北地质矿产杂志》1995,10(4):623-624
环境标志──环境保护的一种新途径李斌（山西省环境保护研究所）为积极开发有益于环境保护的产品，参与国际经济大循环，提高国际市场竞争力，促进企业合理利用资源和能源，并采用无废或少废工艺，提高公众参与意识，国家环境保护局于１９９３年３月决定在我国开展环境标... 相似文献
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