基于高分辨率DEM的裂点序列提取和古地震序列的识别——以霍山山前断裂为实验区

以霍山山前断裂为实验区,基于高分辨率IRS-P5 DEM数据提取了横穿断裂的冲沟,在23条冲沟纵剖面上识别出断裂活动诱发裂点.在其中5条冲沟上识别出1级裂点,裂点几乎位于断裂上;在2条冲沟上识别出2级裂点,最新裂点也位于断裂上.这些位于断裂上的裂点,高度达4～9m,推测它们形成之后并未向上游明显迁移,并可能接受了多次事...     

Rock lead isotopes in northeast Queensland

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.     

多源遥感信息在喀喇昆仑火烧云一带找矿预测中的应用

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。     

Chemical and isotopic variations in the Wiśniówka Mała mine pit water,Holy Cross Mountains (south-central Poland)

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 δ³⁴S_V-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 δ¹⁸O_V-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.     

Distribution of the Permian Monodiexodina in Karakorum and Kunlun and its Geological Significance

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...     

天沃煤矿聚煤特征及对恢复横断山古环境意义

从聚煤沉积环境与聚煤规律判断,矿床形成于古特提斯海消亡、金沙江板块碰撞结合带西侧的晚三叠世（T3）,古地理环境应为滨海海陆交互相。     

秦岭东部李官桥盆地玉皇顶组生物地层划分

长期以来,李官桥盆地始新统玉皇顶组的时代一直被认为是属早始新世。笔者通过野外追索,使盆地中原来分散的化石地点有了层位归属,并于玉皇顶组上部发现了新的哺乳动物化石群。本文将玉皇顶组分为上、中、下三段,并根据各层位哺乳动物化石性质,提出玉皇顶组的时代范围应为早始新世至中始新世早期。     

西天目山南坡垂直自然带分异规律

西天目山为国家自然保护区,生物物种丰富,其南坡垂直自然带谱明显,本文论述西天目山南坡垂直自然带分异规律。     

长白山雪蚀地貌发育特征

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。