从桂西地区金砷汞锑元素的区域分布探讨金的物质来源

文章分析对比了桂西地区Ａｕ、Ａｓ、Ｈｇ、Ｓｂ元素的时空区域分布,并经与岩石样对比,发现上古生界以碳酸盐岩为主的地层为高背景,三叠系为低背景,Ａｕ的高背景区呈ＮＷ向展布,这与右江裂谷区地壳演化的独特历史有关。桂西地区上古生界金主要来自深源,三叠系碎屑岩中金主要来自陆源。从Ａｕ元素丰度与存在形式考虑,高背景的碳酸盐岩夹泥岩、硅质岩、火山岩建造及毗邻的碎屑岩对金成矿更有利。     

CSCO_3 CYCLES IN SALAWUSU RIVER BASINSINCE 150KA B.P.

About 70years ago，Frenc卜卜alaeohdoglst回LL sc卜dars al卜ome and a卜road卜ave successively con－HARD de Chardin P．et al．Initiated the Quaternary ducted large amount ofwork on the Later Quaternarygeologlcal research In the ＞alawusu River Basin of strata（TEILHARD，1924； YUAN，1978； LI，1987；desert region of Northern China and established th，ZHENG，1989； SUN et al，1996； LI et al，1993），Salawusu Formation门EILHARD，1924）．Sine，then，palaeobiology…     

湖南省慈利县农作物富硒程度调查评价与富硒农业发展建议

针对慈利县重点区域进行了农作物富硒程度专项调查,通过建立湖南省相关农作物富硒标准,发现采集的十种农作物中大部分达到富硒标准,其中油菜、水稻、玉米等硒平均含量最高,分别达到0.285mg/kg、0.136 mg/kg以及0.118 mg/kg。通过对比根系土硒含量,研究了十种作物硒富集规律,得出了各农作物硒富集系数,油菜硒富集能力最强,其次为大豆、大蒜。针对慈利县土壤、农作物含硒量特征提出了慈利县富硒农业发展的建议。     

Formation and evolution of Emeishan basalt saprolite in vadose zones of Touzhai landslide source rockmass

In order to explain the formation process of slope hazards, and to identify the key factors leading to instability of a slope, Emeishan basalt saprolite in vadose zones of the Touzhai landslide in Zhaotong, Yunnan, was studied. The formation and evolution of Emeishan basalt saprolite was examined using, amongst other techniques, field investigations, thin section analysis, scanning electron microscopy (SEM) observations, chemical analysis, physical and water-physical property tests of rock masses. Field observations revealed that the majority of the weathered rock blocks were presented as a concentric layer structure in which an internal corestone was enveloped with several layers of external saprolized crust. Chemical and mineralogical analysis identified that iron was the most sensitive element and that the weathering progress usually started with the oxidation of Fe²⁺ to Fe³⁺ in rock blocks. Alkaline elements such as Si, Ca, Mg, Na and K were also dissolved and Fe and Al were concentrated in saprolized crusts. Results indicated that loss on ignition (LOI) also increased significantly. SEM results showed that the weathering intensity of the basalt blocks decreased gradually from the outside to the inside, and the mineral morphology significantly differed on both sides of the weathering front. The saprolized crusts presented cellular microstructure features due to the generation of micropore and clay minerals. Thin section analysis showed that plagioclase was relatively more stable than pyroxene and chlorite during weathering. With a centripetal propagation of the weathering front, saprolized crusts became thicker and corestones became smaller; fresh Emeishan basalt blocks gradually turned into saprolized blocks. Due to the loose structure and low strength of saprolite, the quality of the Emeishan basalt mass significantly deteriorated, this being a potentially important factor which caused the Touzhai landslide to occur.     

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长江上游洪涝暴雨环流形势中期演变趋势分析

本文通过对1980年以来长江上游10次洪涝过程的500hpa环流形势分析,并用车比雪夫多项式对500hpa高度场进行展开,研究了各类洪涝过程的中期演变特征,发现代表不同洪涝过程环流形势变化的不同的车氏系数值都有明显的特征变化,结合欧洲中心中期数值预告96小时500hpa高度场的车氏系数分析,可为洪涝暴雨的中期预报提供一种新的思路。     

地形作用下有限振幅Rossby波的稳定性分析

本文用微分方程定性理论方法分析了地形对有限振幅Rossby波的稳定性影响。结果表明:地形北坡有利于波动出现不稳定,南坡使波动稳定;西坡使导式波动不稳定但使曳式波动稳定,东坡使导式波动稳定但使曳式波动不稳定。     

DISTRIBUTIVE TENDENCY OF ELEMENT CONCENTRATIONS IN LIMESTONE SOILS IN EASTERN CHINA

ＤＩＳＴＲＩＢＵＴＩＶＥＴＥＮＤＥＮＣＹＯＦＥＬＥＭＥＮＴＣＯＮＣＥＮＴＲＡＴＩＯＮＳＩＮＬＩＭＥＳＴＯＮＥＳＯＩＬＳＩＮＥＡＳＴＥＲＮＣＨＩＮＡＷｅｎＹａｎｍａｏ（温琰茂）；ＺｅｎｇＳｈｕｉｑｕａｎ（曾水泉）；ＰａｎＳｈｕｒｏｎｇ（潘树荣）；Ｌｕｏ...