福建戴云山中段变质岩中热液脉型金矿找矿前景分析          下载免费PDF全文

黄昌旗 《地质找矿论丛》2015,30(2):234-240

文章在综合分析福建戴云山中段的成矿地质背景、地球物理、地球化学特征、典型矿床和主要控矿因素的基础上,对该区变质岩中热液脉型金矿找矿潜力和找矿方向作了初步分析,提出了主要找矿靶区。  相似文献   

北京市地质环境质量综合评价     

贾三满  姜媛  赵越 《城市地质》2015,(Z1):111-116

本文选取山区泥石流、崩塌、滑坡、地面塌陷等突发性地质灾害,以及平原区地面沉降、地裂缝和活动断裂等缓变性地质环境问题,作为北京市地质环境质量影响因素。从城市工程地质学观点出发,首先制定各单灾种危险性评价标准,再叠加各因素进行地质环境综合分区评价,将北京市地质环境质量划分为良好、较差和差区。并结合城市规划与防治措施,分析各区地质环境特征及功能规划,为北京市城市规划提供科学依据。  相似文献   

山地休闲度假旅游适宜度评价体系构建与实证研究——以伊犁地区为例     

李东 《干旱区地理》2015,38(2)

山地休闲度假旅游在我国旅游业发展过程中具有重要地位,山地不仅适宜观光、休闲、度假和疗养,还便于开展丰富的休闲类运动和娱乐项目。通过采用特尔菲法和层次分析法,从气候舒适度、度假旅游资源、度假环境条件和区域发展条件4个方面构建山地休闲度假旅游适宜性评价体系,并以伊犁地区为案例进行实证研究,结论如下:(1)准则层的4项指标按照权重从大到小排序为气候适宜度、度假环境条件、度假资源条件和区域发展条件。(2)伊犁地区休闲度假旅游适宜度得分为4.016 6,属于"非常适宜"级别。研究揭示了影响山地休闲度假旅游适宜性的因素及相应的权重,研究结论不仅为山地休闲度假旅游适宜性评价提供新的方法与思路,也为山地休闲度假旅游开发提供了重要的参考依据。  相似文献   

北祁连阿柔地区奥陶纪火山岩岩石学特征及其喷发旋回研究          下载免费PDF全文

徐伟祥  徐均强  张恺  杜韦 《山东国土资源》2015,31(11)

北祁连阿柔地区奥陶纪火山岩分布广泛,发育在早奥陶世阴沟组和晚奥陶世抠门子组。对北祁连阿柔地区奥陶纪火山岩分布特征和岩石学特征进行了研究,划分了3类火山岩岩相：爆发相、喷溢相、喷发沉积相。并划分了2个火山岩喷发旋回：阴沟旋回和扣门子旋回。揭示了阿柔地区祁连洋（裂谷）演化特征,对北祁连地区火山岩区域对比及火山机构恢复具有一定的指导意义。  相似文献   

武隆县羊角场镇厚层灰岩山体大型危岩体破坏模式及成因机制研究   总被引：1，自引：0，他引：1  

王磊  李滨  冯振  高杨  朱赛楠 《地质学报》2015,89(2):461-471

厚层灰岩山体在我国滇黔渝鄂湘等西南山区分布广泛,研究这类山体的破坏模式和成因机理,是对这类危岩体灾害进行风险评估和工程治理的依据,具有重要的意义。本文以重庆武隆羊角场镇区域内大型危岩体为研究对象,通过现场调查,对危岩体的发育分布特征、破坏类型和形成机制进行分析。结果表明:羊角场镇后山陡崖带上分布有大型危岩体11个,总体积约1280×104 m3;根据危岩体形态、结构面特征、变形迹象,危岩体的破坏模式可划分为视向滑动式、滑塌式、倾倒式和落石破坏式4种类型;控制研究区大型危岩体形成的主要因素有斜坡结构类型、岩性组合、岩体结构、岩溶作用和采矿活动等。  相似文献   

Water resources in mountain regions: a methodological approach to assess the water balance in a highland‐lowland‐system     

Rolf Weingartner  Daniel Viviroli  Bruno Schädler 《水文研究》2007,21(5):578-585

Mountains and highlands are typically areas that provide considerable quantities of water, the latter being an important resource for the lowlands. These run‐off quantities remain discernible in the superior‐scale river systems and significantly contribute to the global water resources. Therefore, mountain regions ought to be given specific consideration with regard to management endeavours. Although well known in principle, details of water resources originating from mountains remain under discussion. A new approach has been introduced, which depicts the water balance of Switzerland in a spatially distributed manner, based on catchments of about 150 km². The main feature of this approach is the areal precipitation, which is calculated using run‐off, evaporation and storage change of glaciers, instead of being derived from gauged precipitation values. This methodology was selected because measurement and regionalization of precipitation remain subject to large uncertainties in mountainous areas. Subsequently, the view is widened to the European Alps, which, as compared with the surrounding lowlands, contribute considerably higher annual discharge, especially in the summer months. Finally, the focus is put on the hydrological significance of mountains in general. In dry regions, mountains, in particular, are indispensable contributors to the water resources downstream. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

新疆天山-北山成矿带区域地球化学特征     

王虹  刘拓  王庆明  郑启平 《地球科学与环境学报》2007,29(2):141-144

根据地质构造和矿产分布特征,将天山—北山成矿带划分为西南天山、东天山、西天山、北山4个单元。依据1∶20万水系沉积物测量数据,对比分析了主要成矿元素在整个成矿带及4个构造单元的背景值、元素的空间分布规律、元素富集特征及其与成矿的关系等。得出西南天山、西天山元素富集特征反映了以金为主的矿化特征;东天山反映以金、铜(镍)、银多金属为主的矿产格架,北山是以金为主矿化特征。  相似文献   

Characteristics of water stable isotopes and hydrograph separation in Baishui catchment during the wet season in Mt.Yulong region,south western China     

Tao Pu  Yuanqing He  Guofeng Zhu  Ningning Zhang  Jiankuo Du  Chunfeng Wang 《水文研究》2013,27(25):3641-3648

Glaciers are of crucial importance for the livelihood of the local populations, which depend on their meltwater for water and energy supplies. For this reason, seasonal variations of oxygen‐18 of glacial stream water and their sources within a small glacial catchment in south western China were investigated during the wet season. The results showed significant difference of oxygen‐18 existed among meltwater, rainwater, ground water and stream water, and significantly seasonal variation of precipitation occurred during the observed period. The streamflow of Baishui catchment was separated into components of ice‐snowmelt and precipitation using oxygen‐18. As shown by the result of the two‐component mixing model, on average, 53.4% of the runoff came from ice‐snowmelt during the wet season, whereas the remaining 46.6% were contributed by precipitation in the catchment. According to monthly hydrograph, the contribution of snow and glacier meltwater varied from 40.7% to 62.2%, and that of precipitation varied from 37.8% to 59.3% in wet season. Uncertainties for this separation were mainly caused by the variation of tracer concentrations. The roles of glacier and snow meltwater should be noticed in water resource management in those glacial regions in south western China. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Evaluating the use of a gridded climate surface for modelling groundwater recharge in a semi‐arid region (Okanagan Basin,Canada)     

B. D. Smerdon  D. M. Allen  D. Neilsen 《水文研究》2010,24(21):3087-3100

Spatially distributed groundwater recharge was simulated for a segment of a semi‐arid valley using three different treatments of meteorological input data and potential evapotranspiration (PET). For the same area, timeframe, land cover characteristics and soil properties, groundwater recharge was estimate using (i) single‐station climate data with monthly PET calculated by the Thornthwaite method; (ii) single‐station climate data with daily PET calculated by the Penman–Monteith method; and (iii) daily gridded climate data with spatially distributed PET calculated using the Penman–Monteith method. For each treatment, the magnitude and distribution of actual evapotranspiration (AET) for summer months compared well with those estimated for a 5‐year crop study, suggesting that the near‐surface hydrological processes were replicated and that subsequent groundwater recharge rates are realistic. However, for winter months, calculated AET was near zero when using the Thornthwaite PET method. Mean annual groundwater recharge varied from ～3·2 to 10·0 mm when PET was calculated by the Thornthwaite method, and from ～1·8 to 7·5 mm when PET was calculated by the Penman–Monteith method. Comparisons of bivariate plots of seasonal recharge rates estimated from single‐station versus gridded surface climate reveal that there is greater variability between the different methods for spring months, which is the season of greatest recharge. Furthermore, these seasonal differences are shown to provide different results when compared to the depth to water table, which could lead to different results of evaporative extinction depth. These findings illustrate potential consequences of using different approaches for representing spatial meteorological input data, which could provide conflicting predictions when modelling the influence of climate change on groundwater recharge. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

黄山冬季气温分类及雪、雨凇和雾凇的气候分析   总被引：18，自引：0，他引：18  

吴有训  陈健武  杨保桂  张兵  江斌  徐巍  王进宝 《气象学报》2000,58(3):376-384

用对应分析方法对黄山1956～1996年冬季气温进行聚类分析。结果表明：Ⅰ类冬季气温特点,后冬冷于前冬,隆冬气温很高,冬季气温低;Ⅱ类特点,前冬暖后冬冷,隆冬气温很低,冬季气温正常;Ⅲ类后冬暖前冬冷,隆冬气温偏高,冬季气温高。Ⅰ类冬季降雪、积雪、雨凇和雾凇日数多;Ⅱ类冬季积雪日数多,降雪、雨凇和雪凇日数少;Ⅲ类冬季降雪日数正常,雨凇日数偏多,积雪和雾凇日数偏少。各类冬季降雪、积雪、雨凇和雾凇日数的冬季月分布差异明显。ENSO对黄山冬季气温有明显影响,ElNino年黄山多为暖冬年份,冬季平均气温正距平百分比18．8％。关于中高纬度和极区环流与黄山冬季气温关系也进行了初步探讨。  相似文献