初论成矿场与矿产勘查意义     

魏俊浩 《地质科技通报》2020,39(1):114-129

成矿场是指地质历史时期某成矿地区引起岩石变形的应力场,承载成矿作用引起流体效应的流体场,以及成矿元素迁移、沉淀、富集、叠加改造形成的物质场的总称.分析了一个成矿地区应力场、流体场、物质场的空间关系、研究内容与研究方法.根据成矿背景、控制因素、成矿环境将其分为7类成矿场,即:逆冲(推覆)-后伸展构造背景成矿场、走滑-伸展(伸展-走滑)-后逆冲构造背景成矿场、中酸性火山(次火山)岩浆活动背景成矿场、基性-超基性岩浆活动背景成矿场、盆地裂谷-海底喷流环境成矿场、外生海相建造环境成矿场、外生陆相建造环境成矿场.对前5类成矿场(以内生矿产为主)进行了系统的内涵表述.在此基础上对前5类成矿场的矿产勘查过程中关键地质因素进行了归纳分析,这对具体矿产勘查工作具有现实的指导意义.  相似文献   

Comparative Analysis of Nutrient Composition of Caulerpa lentillifera from Different Regions     

Meijian Zhang  Yurong Ma  Xinyi Che  Zumei Huang  Peng Chen  Guanghua Xia  Meihui Zhao 《中国海洋大学学报(英文版)》2020,19(2):439-445

This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were determined and compared with those from Semporna(Malaysia),Sabah(Malaysia),Petchburi(Thailand),and two other species of seaweeds(Malaysia).The results showed that the polysaccharide and protein contents of C.lentillifera from Hainan(44.82%±0.98%and 12.5%±0.70%),Shandong(43.22%±1.42%and 14.7%±0.72%),Petchburi(59.27%±2.31%and 12.49%±0.30%),and Sabah(44.02%±2.01%and 19.38%±1.48%)were higher than those of Eucheuma cottonii(26.49%±3.01%and 9.76%±1.33%)and Sargassum polycystum(33.49%±1.70%and 5.40%±0.07%),respectively.The polyunsaturated fatty acid contents in C.lentillifera from Hainan(29.98%)and Shandong(22.11%)were higher than that in Semporna(16.76%±0.27%),Sabah(9.49%),and S.polycystum(20.34%±0.43%),but lower than that in E.cottonii(51.55%±0.57%).In Caulerpa lentillifera of Hainan and Shandong provinces,the essential amino acid(EAA)/total amino acid(TAA)ratios were 35.22%and 38.78%,respectively;and the EAA/ETAA ratios were 54.36%and 63.35%,respectively.The EAA composition of C.lentillifera was close to the ideal model of Food and Agriculture Organization/World Health Organization.C.lentillifera was rich in mineral elements,including calcium((3315.85±127.55)mg(100 g)^-1 and(3728.35±92.38)mg(100 g)^-1),magnesium((6715.74±82.58)mg(100 g)^-1 and(8128.59±242.72)mg(100 g)^-1),and trace elements,including iron((510.65±5.47)mg(100 g)^-1 and(1972.97±183.35)mg(100 g)^-1),selenium((1.04±0.08)mg(100 g)^-1 and(0.83±0.15)mg(100 g)^-1),and zinc((33.90±0.13)mg(100 g)^-1 and(11.75±2.05)mg(100 g)^-1).These results showed that C.lentillifera was more nutritious than S.polycystum or E.cottonii in terms of polysaccharide,protein,and fatty acid contents.Furthermore,both C.lentillifera species collected from Hainan and Shandong provinces show more basic nutrients.Therefore,C.lentillifera has important development and application prospects.  相似文献   

地理国情监测在领导干部自然资源资产离任审计工作中的应用探讨     

张峰 《测绘与空间地理信息》2017,(12):126-128

为积极配合审计部门开展领导干部自然资源资产离任审计工作,充分利用地理国情普查及监测成果,探索领导干部自然资源资产离任审计的内容、方法和评价指标体系,探讨了基于地理国情普查和监测数据成果、基础测绘及相关技术获取的各类自然资源资产基础数据。按专业部门现行标准与有关行业部门进行必要的专题数据整合和处理,建设市级自然资源本底数据库,摸清自然资源的存量与变量,为建立自然资源资产审计长效机制奠定扎实的基础。  相似文献   

块状岩石矿物组分热红外光谱反演实验研究     

李天子  王晓华  赵晨光 《测绘科学》2017,(12):190-194

针对地面研究用岩石的热红外光谱反演其矿物组分过程中,由于自然岩石内矿物组分分布不均匀,给确定观测区域内矿物组分的精确值造成困难的问题,该文采用块状矿物拼接的方法模拟自然岩石,使模拟岩石的矿物组分可以精确获取。进一步,针对模拟岩石制订旋转试样法观测方案,从理论上研究该方案存在的观测误差,并通过光谱解混验证其观测精度。  相似文献   

自然灾害对公共安全的影响及其监测预警科技发展战略          下载免费PDF全文

毕宝贵  李泽椿  郭安红  王月冬 《山东气象》2017,37(3):1-7

改革开放以来,我国在自然灾害监测预警的各个环节均取得了可喜的发展,对减轻灾害损失、保障人民生命财产安全和社会稳定繁荣发展发挥了重要作用。但仍需清醒地认识到,在灾害规律演变、社会经济发展的新形势下,各类自然灾害对国家公共安全仍存在很大的威胁;我国目前灾害监测预警能力与国家防灾减灾“三个转变”需求以及国际先进水平相比仍存在较大差距。因此,本文简要论述了气象、海洋、地质、地震、生物五大自然灾害对国家公共安全的影响,并根据我国目前监测预警状况和存在问题,提出未来5～10 a我国自然灾害监测预警科技发展战略要从加强预测预报基础理论研究、提升综合监测能力、构建高效自然灾害预警系统以及发展减灾避灾和救灾技术四个方面着手推进。  相似文献   

Perceptions of Local People on the Use of Nyabarongo River Wetland and Its Conservation in Rwanda     

Venuste Nsengimana  Simeon Weihler  Beth A. Kaplin 《社会与自然资源》2017,30(1):3-15

This research presents a case study on perceptions of local people on the use of Nyabrongo river wetland and its conservation in Rwanda. It critically examines the potential implications of a shift in wetland use and management practices for local people and presents empirical data from a household survey, group discussions, and observations from transect walks. Results showed that the change in the use and management regime of Nyabarongo river wetland poses substantial loss for local people in terms of provision of resources, income, and access to the wetland, so that the majority of the participants are not happy with the current use of the wetland. Research concluded that there should be participation of all stakeholders, including local people, during policy development in order to shift from command-and-control toward local stakeholder integration in decision making.  相似文献   

A mineral magnetic and scaled-chrysophyte paleolimnological study of two northeastern Pennsylvania lakes: records of fly ash deposition, land-use change, and paleorainfall variation   总被引：2，自引：0，他引：2  

K. P. Kodama  J. C. Lyons  Peter A. Siver  Anne-Marie Lott 《Journal of Paleolimnology》1997,17(2):173-189

A combined mineral magnetic and scaled chrysophyte study of lake sediments from Lake Lacawac and Lake Giles in northeastern Pennsylvania was conducted to determine the effects of land-use and sediment source changes on the variation of pH, conductivity, and alkalinity inferred from biotic changes. Ten 30–40 cm long gravity cores were collected from Lake Lacawac and three from Lake Giles. Isothermal remanent magnetizations (IRMs) were given to the lake sediments in a 1.3 T magnetic field to measure magnetic mineral concentration variations. IRM acquisition experiments were conducted to identify magnetic mineralogy. The bedrock, soils and a peat bog on the shores of Lake Lacawac were also sampled for magnetic analysis to determine possible lake sediment sources. The top 10 cm of sediment collected from Lakes Lacawac and Giles was two to four times more magnetic than deeper sediment. ²¹⁰Pb dating suggests that this intensity increase commenced circa 1900. SEM images of magnetic extracts from the highly magnetic sediments indicates the presence of magnetic fly ash microspheres from fossil fuel burning electric power generation plants. The similarity in magnetic coercivity in the top 8 cm lake sediments and in the peat bog supports an atmospheric source for some of the magnetic minerals in the youngest lake sediments. The highly magnetic sediments also contain an antiferromagnetic mineral in two cores closest to Lake Lacawacs southeastern shore. This magnetic mineral is only present deep in the soil profile and would suggest erosion and significant land-use changes in the Lacawac watershed as another cause for the high magnetic intensities (concentrations) in the top 10 cm of the lake sediments. The most significant changes in the scaled chrysophyte flora occurred immediately above the 10 cm level and were used to infer a doubling of the specific conductivity between circa 1910 and 1929. These variations also support land-use changes in the Lacawac catchment at this time. A similar shift in the scaled chrysophte flora was not observed in the top of Lake Giles, however, distinct changes were found in the deeper sections of the core coupled with a smaller peak in magnetic concentration. Fourier analysis of the ²¹⁰Pb-dated lake sediment magnetics indicates the presence of a 50 year period, low amplitude variation in the Lake Lacawac, Lake Giles, and Lake Waynewood (Lott et al., 1994) magnetic concentration records. After removal of the land-use/fly ash magnetic concentration peak by Gaussian filtering, the 50 year variation correlates strongly from lake to lake even though the lakes are in different watersheds separated by up to 30 km. When this magnetic variation is compared with Gaussian-filtered rainfall variations observed in New York City and Philadelphia over the past 120–250 years there is a strong correlation suggesting that magnetic concentration variations can record regional rainfall variations with an approximately 50 year period. This result indicates that magnetics could be used to document regional variations in climatic change.  相似文献   

中国人地关系及人地关系地域系统研究方法述评   总被引：4，自引：0，他引：4  

李扬  汤青 《地理研究》2018,37(8):1655-1670

人地关系及人地关系地域系统是地理学基础理论研究的本质所在,其研究方法的发展和完善不仅能促进人地关系研究的不断深化,而且可以更有效地解决经济社会发展中出现的复杂资源环境问题。在梳理人地关系及人地关系地域系统的内涵及研究脉络基础上,从哲学和环境史、可持续发展、人地关系地域系统研究方法、人地关系综合表征方法等四方面评述了中国人地关系及人地关系地域系统的研究方法,并提出了未来的发展趋势。① 伴随着人地关系及人地关系地域系统内涵的不断演变,人地关系地域系统的研究方法也不断发展,丰富了人地关系的理论内涵和方法体系。② 人地关系地域系统的不同研究方法各具特点,并且各有其适用性和局限性,总体上是往综合集成方向发展,如生态足迹和资源环境承载力等,是人地关系综合集成研究的有益探索。③ 提出人地关系地域系统研究方法未来的发展趋势包括发展自然要素和人文要素耦合的综合集成研究方法,加强新技术手段和新研究方法的运用,完善资源环境基础和资源环境承载力等综合研究的理论体系。  相似文献   

海南岛人工与天然红树林重金属污染、 富集与转运能力比较     

邱彭华  王德智  谢跟踪  徐颂军  曹瑞  王军广 《热带地理》2018,38(6):836-847

以海南岛东寨港、清澜港与三亚河3个红树林自然保护区为研究区,综合比较了人工与天然红树林6种重金属（Cd、As、Cu、Cr、Pb和Zn）的地累积指数、潜在生态危害指数、生物富集系数与转运系数的差异。结果表明：1）研究区红树林沉积物中,Cd呈现强度—极强度污染,As为中度—强度污染,Cr属中度污染,Zn为轻度污染,Cu与Pb表现为无至轻度污染;从区域空间看,Cd污染表现为：东寨港（强度—极强度）＞清澜港（强度）＞三亚河（无污染）,As污染表现为：清澜港（中度—强度）＞东寨港（中度—强度）＞三亚河（中度）;Cr污染表现为：东寨港（中度）＞清澜港（轻度）＞三亚河（无污染）。2）东寨港人工无瓣海桑、天然白骨壤、人工与天然桐花树、人工与天然海莲,清澜港的天然桐花树Cd的值（单一重金属潜在生态危害系数）属较强潜在生态风险,东寨港与清澜港的天然正红树林、清澜港的人工无瓣海桑、天然杯萼海桑和天然海莲Cd的值属中等潜在生态风险,其余红树植物6种参评元素的值与RI值（多重金属总潜在生态风险指数）均属轻微级;综合而言,Cd、As、Pb和Cr似乎更易引发海莲、桐花树与无瓣海桑的健康风险问题。3）人工与天然红树植物各器官对6种参评重金属的富集系数大体表现为：根＞枝＞叶;红树植物植株平均富集系数总趋势为：三亚河人工红树林＞三亚河天然红树林＞清澜港天然红树林＞东寨港天然红树林＞清澜港人工红树林＞东寨港人工红树林。4）人工与天然红树林的重金属转运系数都显示出：叶—枝＞枝—根＞叶—根;植株平均转运系数总趋势：三亚河人工红树林＞三亚河天然红树林＞东寨港天然红树林＞东寨港人工红树林＞清澜港天然红树林＞清澜港人工红树林。5）红树植物与林下沉积物重金属含量之间具有强的正相关关系,这表明控制沉积物重金属含量和减少外源重金属污染是维护红树林湿地生态系统健康重要而有效的环节。6）同一地区同种红树植物在吸附重金属能力上人工林略强于天然林,这可能与人工红树林的营林环境、人为扰动存在一定关联。  相似文献   

中国气温变化对全球变暖停滞的响应   总被引：4，自引：3，他引：1  

杜勤勤  张明军  王圣杰  车存伟  邱雪  马转转 《地理学报》2018,73(9):1748-1764

1998-2012年出现的全球变暖停滞（global warming hiatus）现象,近年来受到各界的广泛关注。基于中国622个气象站的气温数据,研究了全国及三大自然区气温变化对全球变暖停滞的响应。结果表明：① 1998-2012年间,中国气温变化率为-0.221 ℃/10 a,较1960-1998年增温率下降0.427 ℃/10 a,存在同全球变暖停滞类似的增温减缓现象,且减缓程度更明显,其中冬季对中国增温减缓的贡献最大,贡献率为74.13%,夏季最小;② 中国气温变化对全球变暖停滞的响应存在显著的区域差异,从不同自然区看,1998-2012年东部季风区和西北干旱区降温显著,其中东部季风区为中国最强降温区,为全国增温减缓贡献了53.79%,并且具有显著的季节依赖性,减缓期冬季气温下降了0.896 ℃/10 a,而夏季上升了0.134 ℃/10 a。青藏高寒区1998-2012年增温率达0.204 ℃/10 a,对全球变暖停滞的响应并不显著;③ 中国增温减缓可能受太平洋年代际振荡（PDO）负相位、太阳黑子数与太阳总辐照减小等因素的影响;④ 1998-2012年中国虽出现增温减缓现象,但2012年之后气温快速升高,且从周期变化看,未来几年可能持续升温。  相似文献