南黄海沉积物的元素地层学研究     

蓝先洪  张志珣  李日辉 《海洋地质前沿》2008,24(12):1-4

元素地层学是海洋沉积学研究的重要内容之一，海底沉积物中元素或元素组合的时间变化规律的研究可以用于地层的划分和对比。元素地层学取得较大进展的主要表现在大陆地质的研究中，而在海洋地质研究中却进展较缓慢。论述了近年来随着南黄海海洋地质调查的不断深入，在元素地层学研究中取得的成果。  相似文献   

组合异常分类及评序方法的应用     

赵冬波  赵莉  宋延山 《黑龙江国土资源》2009,(9):47-47

一、组合异常圈定 在圈定单元素异常的基础上，圈定组合异常。有三种以上单元素异常相套合的异常以作为一个组合异常，并给予编号。当二种单元素异常相重迭面积较大或含量较高者也可以圈定组合异常、并给予编号根据以上的原则，本区共圈定出组合异常28处。  相似文献   

Dynamics and relationships of Ca, Mg, Fe in litter, soil fauna and soil in Pinus koraiensis-broadleaf mixed forest   总被引：1，自引：0，他引：1  

Bo Song  Xiuqin Yin  Yu Zhang  Weihua Dong 《中国地理科学(英文版)》2008,18(3):284-290

The Liangshui Natural Reserve in Heilongjiang Province of China was selected as the study area. The authors collected the samples of forest litter （Tilia amurensis, Fraxinus mandshurica, Pinus koraiensis, Acer mono, Betula costata, and mixed litter）, soil in humus horizon （0--5cm） and soil horizon （5-20cm）, and soil macrofauna （Oligochaeta, Geophiloporpha and Juliformia） from 2001 to 2002. The role of soil macrofauna in the material cycle was analyzed through comparing the macro-element contents among various parts of the subsystems and using enrichment index （El）. The results indicate that dynamic changes of various litters are very complicated. The contents of Fe in each kind of litter increase firstly, and then decrease in the study period. The changes of macro-element contents are greater in the broad-leaf litter than in the coniferous litter, and the mixed litter is in the middle level, but the differences among them are not significant. The contents of Mg and Fe in humus are higher than those in soil, but the contents of Ca in soil are higher than that in humus. The dynamic changes of macro-element contents in soil and soil fauna are not consistent with those in litter. The diplopod presented obvious enrichment of Ca and Mg （E1〉1）, but it does not significantly enrich Fe. Earthworm has a stronger enrichment ability of Fe than diplopod and scolopendra, but E1〈1. Soil fauna can make great influences on the material cycle of the subsystems.  相似文献   

土地祛毒：为了中国农业的明天     

《国土资源》2004,(1):17-19

我国是一个农业大国。农业、农村和农民（即“三农”)问题的解决是关系改革开放和现代化建设全局的重大的基础性问题。  相似文献   

可可西里苟仁错湖泊沉积物元素地球化学特征及其环境意义   总被引：18，自引：4，他引：14  

吴艳宏  李世杰  夏威岚 《地球科学与环境学报》2004,26(3):64-68

湖泊沉积物元素地球化学特征及其比值，有效地揭示了湖泊沉积物物源区的化学风化程度．已成为反映古气候波动的有效指标。根据可可西里苟仁错湖泊沉积物的元素地球化学特征，通过CIA，ICV等元素比值的结果，揭示该地区1400AD以来化学风化作用十分微弱，因此湖泊沉积物元素组成，对气候变化非常敏感。研究表明1400AD以来该地区气候经历多次冷暖波动，且呈干旱化的趋势，1420AD左右进入小冰期，其中1480～1520AD最为寒冷，1900AD后干旱化加剧。  相似文献   

土壤离子电导率测量找矿中真假异常的判别及质量检验标准     

罗光熔 《地质与勘探》1990,26(10):52-54

针对应用土壤离子电导率测量法找矿预测出现的干扰异常,就如何识别真假异常进行了探讨.对该方法的质量检验标准从两个方面作了论述,并给出质量检验标准的计算公式  相似文献   

Isotopic tracing of ore-forming source materials for Dexing porphyry copper deposit of Jiangxi, China     

References： 《东北亚地学研究》2008,11(1):25-31

Dexing copper deposit is the biggest porphyry copper deposit in China. By researching isotopes of C, Si and Cu from the samples of Tongchang and Fujiawu ore-field, the authors found that δ^13 CpDB values of siderite were close to the δ^13 CpDB value of original magma; δ^30Si values of the samples at the ore-forming stage were close to the δ^30 Si value range of magma, δ^30Si values of partial samples were far away from it; Cu isotopic compositions of massive chalcopyrite formed at the early ore-forming stage are higher than that of veinal chalcopyrite formed at the later ore-forming stage. The results show that ore-forming materials were mainly derived from the porphyry body, and part of them were from wall rock materials.  相似文献   

Impacts of soil fauna on litter decomposition at different succession stages of wetland in Sanjiang Plain, China   总被引：1，自引：0，他引：1  

Haitao Wu  Xianguo Lu  Ming Jiang  Xiao Bao 《中国地理科学(英文版)》2009,19(3):258-264

Litter decomposition is the key process in nutrient recycling and energy flow. The present study examined the impacts of soil fauna on decomposition rates and nutrient fluxes at three succession stages of wetland in the Sanjiang Plain, China using different mesh litterbags. The results show that in each succession stage of wetland, soil fauna can obviously increase litter decomposition rates. The average contribution of whole soil fauna to litter mass loss was 35.35%. The more complex the soil fauna group, the more significant the role of soil fauna. The average loss of three types of litter in the 4mm mesh litterbags was 0.3–4.1 times that in 0.058mm ones. The decomposition function of soil fauna to litter mass changed with the wetland succession. The average contribution of soil fauna to litter loss firstly decreased from 34.96% (Carex lasiocapa) to 32.94% (Carex meyeriana), then increased to 38.16% (Calamagrostics angustifolia). The contributions of soil fauna to litter decomposition rates vary according to the litter substrata, soil fauna communities and seasons. Significant effects were respectively found in August and July on C. angustifolia and C. lasiocapa, while in June and August on C. meyeriana. Total carbon (TC), total nitrogen (TN) and total phosphorus (TP) contents and the C/N and C/P ratios of decaying litter can be influenced by soil fauna. At different wetland succession stages, the effects of soil fauna on nutrient elements also differ greatly, which shows the significant difference of influencing element types and degrees. Soil fauna communities strongly influenced the TC and TP concentrations of C. meyeriana litter, and TP content of C. lasiocapa. Our results indicate that soil fauna have important effects on litter decomposition and this influence will vary with the wetland succession and seasonal variation. Foundation item: Under the auspices of State Key Development Program for Basic Research of China (No. 2009CB421103), Key Program of National Natural Science Foundation of China (No. 40830535/D0101), Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-BR-16, KSCX2-YW-N-46-06)  相似文献   

科学家称生命进化曾因缺氧中断20亿年     

《海洋世界》2008,(4):6-6

一个国际科学家小组发现，由于缺氧和海洋中缺乏重金属元素钼，地球上生命的进化曾中断了约20亿年。  相似文献   

美国土地利用规划立法和编制的主要特点及其启示     

刘旭 《国土资源导刊(湖南)》2007,4(3):68-71

一、美国土地管理概况美国土地面积936.48万平方公里,人口3亿,人口密度为30人/平方公里。广阔的地域、肥沃的土壤、丰富的资源、稀少的人口为美国的长盛不衰提供了得天独厚的优越条件。美国是公私兼有的多元化资本主义土地所有制,其中私  相似文献