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U‐Pb and Th‐Pb studies of rocks from an extensive Palaeozoic volcano‐plutonic province in northeast Queensland support conclusions derived from a previous Rb‐Sr study. The data oppose an earlier hypothesis, that two widespread and fundamentally different magma types are present. Interpretation of the lead data, however, must be treated with some caution since uranium movement apparently begins at a very early stage of weathering; X‐ray fluorescence data are displayed in a manner which suggests a simple rejection criterion. 相似文献
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多源遥感信息在喀喇昆仑火烧云一带找矿预测中的应用 总被引:1,自引:0,他引:1
本文采用多源遥感数据,开展新疆喀喇昆仑萨岔口-火烧云一带铅锌矿找矿预测工作。在对研究区典型矿床不同岩、矿石光谱特征测量的基础上,总结分析其光谱特征。赋矿灰岩具有强CO_3~(2-)吸收峰、弱Al-OH吸收峰,铅锌矿化体具有CO_3~(2-)吸收峰、Fe~(3+)吸收峰和Al-OH吸收峰。利用比值分析、密度分割和多特征匹配滤波等方法对ASTER数据有针对性地提取方解石、铁染、Al-OH遥感异常信息,异常呈北西向带状展布与区域地质体展布相吻合。本文以火烧云铅锌矿区为例,建立了区域铅锌矿床以"强方解石、弱Al-OH异常,伴有铁染异常"为特征的遥感找矿标志。结合Worldview-2高分辨率遥感影像特征及构造解译,以及成矿信息综合分析的基础上,对研究区内遥感异常信息进行筛选。利用相似类比理论,圈定五处找矿有利部位。结合异常查证,显示萨岔口、马鞍山、牛郎山、歪头山、金鱼山具有较好的铅锌矿找矿前景。利用多源遥感信息有助于推动喀喇昆仑这类高寒景观区的铅锌找矿工作。 相似文献
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Zdzisław M. Migaszewski Agnieszka Gałuszka Stanisław Hałas Józef Dąbek Sabina Dołęgowska Irena Budzyk Ewa Starnawska Artur Michalik 《Environmental Geology》2009,57(1):29-40
In 2005 and 2006, hydrogeochemical study was carried out in the bipartite Wiśniówka Mała pit lake of the Holy Cross Mountains
(south-central Poland). This is the largest acidic water body in Poland. This report presents the element concentrations in
the water and sediment, stable sulfur and oxygen isotope ratios in the soluble sulfates, and stable oxygen isotope ratio in
the water. The scope of the investigation also encompassed mineralogical examinations (scanning electron microscope, X-ray
diffraction) of the sediment. The results of this study show that there is a spatial and temporal variability in concentrations
of most elements and sulfur isotope ratios in the examined pit lake. The water of the western pond displayed a lower pH with
a mean of 3.73 and higher conductivity (390 μS cm−1) as well as higher concentrations of sulfates (156 mg L−1) and most of the cations and anions. The concentrations of Fe2+ and Fe3+ averaged 0.8 and 0.4 mg·L−1. In contrast, the eastern pond water revealed a higher pH (mean of 4.36), lower conductivity (293 μS cm−1) and lower sulfate (90 mg L−1) and trace metal levels. Similar variations were recorded in the stable sulfur isotope ratios. The δ34SV-CDT(SO4
2−) values in the water of the western pit pond were in the range of −6.7 to −4.6‰ (mean of −5.6‰), whereas that in the eastern
pit pond ranged from −2.2 to −0.9‰ (−1.6‰). The alkalinity of the entire lake water was below 0.1 mg·L−1 CaCO3. No distinct difference in the δ18OV-SMOW(SO4
2−) was noted between the western and eastern pit ponds. Compared to the Purple Pond in the Sudetes (Poland) and similar sites
throughout the world, the examined pit lake is highlighted by distinctly low concentrations of sulfates, iron and other trace
metals. Based on this and other studies performed in the Holy Cross Mountains, a conclusion can be drawn that the SO4
2− in the Wiśniówka Mała pit lake water is a mixture of SO4
2− derived from the following sources: (1) pyrite oxidation (especially in the western pond water), (2) leaching of soluble
sulfates from soils and waste material, as well as (3) subordinate deposition of airborne sulfate precipitation. 相似文献
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YAO Jianxin WANG Naiwen XIAO Xuchang JI Zhansheng WU Guichun WU Zhenjie LI Boqin WANG Jun WANG Yong ZHAI Qingguo Institute of Geology Chinese Academy of Geological Sciences Beijing China Chang'an University Xi'an Shaanxi China 《《地质学报》英文版》2009,83(2)
The Permian fusulinoidean genus Monodiexodina is widely distributed in east Tethys.The genus might be an important indicator for the northern margin of Gondwana in northwestern China, but this is disputed.Monodiexodina-bearing areas can be restored as in either northern or southern middle latitudes with a symmetrical distribution between a high latitudinal,cool/cold water climatic realm and a paleotropical,warm water realm.Permian strata bearing Monodiexodina in Karakorum, Muztag Pear,and Buka Daban Pear... 相似文献
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长白山雪蚀地貌发育特征 总被引:1,自引:0,他引:1
在中国东北长白山广泛发育着雪蚀地貌,尤其以雪蚀洼和高夷高阶地最为多见。与世界其它地区相比,长白山发育的雪蚀地貌具有规模小,形成年代久,成因复杂等特点,此外,通过野外半定位观测发现,雪蚀洼地年下蚀作用存在着不均一性,本着重对上述方面进行论述。 相似文献