贵州台江县大塘铅锌矿找矿前景浅析

大塘铅锌矿位于黔东铅锌成矿带中段,区域性施洞口断裂北西侧,矿体及矿化体呈似层状、脉状和透镜状赋存于下寒武统清虚洞组及中寒武统石冷水组地层中,含矿岩系为角砾状白云岩,矿石矿物主要为闪锌矿、方铅矿及少量黄铁矿,脉石矿物主要为白云石及少量方解石。矿石结构以粒状结构和假象结构为主,矿石构造主要为浸染状、细脉状和角砾状构造。该类型铅锌矿矿床有一定的规模,找矿标志明显。黔东铅锌成矿带中段内有铅锌矿点和铅锌地球化学异常区多处,通过了解该类型铅锌矿床地质特征和找矿标志,可望找到更多、更大的铅锌矿。     

碎屑锆石对班公湖地区晚侏罗世-早白垩世沉积物源的制约

本文对班公湖地区中生代沙木罗组（J3—K1s）和日松组（J3r）地层的碎屑锆石进行了形态学及U-Pb年代学的研究。结果表明：锆石颗粒粒径约为100～150 μm,内部结构清晰,晶体为长柱状,自形程度较高,多数锆石不含暗色包体及浑圆形内核; 有些锆石颗粒有扇型分带结构。Th/U比值较大,多数大于0.1,均值约为0.86,说明岩浆的成因以锆石为主体,部分颗粒或晶体可能为变质成因; 锆石年龄主要分布在6个区间范围内： 1）180～100 Ma, 2）350～180 Ma, 3）600～450 Ma, 4）1100～600 Ma, 5）1800～1400 Ma, 6）2200～1800 Ma。锆石U-Pb年龄谱对应了羌塘地块经历的几次构造热事件,验证了晚侏罗世—早白垩世班公湖地区的物源主要来自其北部的羌塘地块。     

Human Health Risk Assessment Model of Organic Pollution in Groundwater: Shijiazhuang Industrial Zone

In this study, a risk-based management model is developed and applied to an industrial zone. The models proposed by the United States Environmental Protection Agency and Han Bing have been improved by adding a residual ratio of volatile organic compounds (VOC) after boiling and deleting the related parameters in half-life. Using this improved model, an integrated process was used to assess human health risk level in the study area. Compared with water quality analysis, the results highlight the importance of applying an integrated approach for decision making on risk levels and water protection. The results of this study demonstrated that: (1) Compared with these permissible level standards in China (GB 3838-2002) and National Primary Drinking Water Regulations of the United States, the residents’ daily life had not been affected by the groundwater in this area (except for relative bad water quality of HB3-4 and HB3-6); (2) The typical detected organic contaminants of all groundwater samples were chloroform, carbon tetrachloride, trichloroethylene and tetrachloroethene, and the pollution sources were mainly industrial sources by preliminary investigations; (3) As for groundwater, the non-carcinogenic risk values of all samples do not exceed the permissible level of 1.0 and the carcinogenic risk values are relatively lower than the permissible level of 1.00E-06 to 1.00E-04; (4) Drinking water pathway of trichloroethylene and tetrachloroethylene mainly contribute to increasing the health risk of residents’ in study areas; (5) In terms of non-carcinogenic risk and carcinogenic risk, the health risk order for drinking water pathway and dermal contact pathway was: drinking water pathway > dermal contact pathway.     

浙江萧山跨湖桥遗址动物骨骼表面微痕与人类行为特征

浙江跨湖桥遗址位于中国东南沿海,是距今约8000年左右的新石器时代遗址.遗址中出土有大量哺乳动物骨骼,通过显微观测和统计,发现遗址动物骨骼表面有丰富的人工改造痕迹,并有家畜狗的啃咬痕迹等.其中人工改造痕迹的比重,达到所观察标本总数的17.57%.人工改造痕迹的显微特征、排列规律、分布位置等,反映遗址古居民已熟练掌握了剥...     

甘肃省临夏盆地更新世早期湖泊沉积孢粉记录的古气候演化

根据孢粉组合特征,将临夏盆地早更新统东山组(2.50-1.76Ma)的孢粉划分为3个孢粉带(含6个亚带),即3个植被、气候阶段,第一阶段(2.50-1.91Ma,带Ⅰ),植被类型是以柏科、榆属和禾本科为优势种的温带森林,气候表现为温凉稍干,并有逐渐干旱化的趋势.第二阶段(1.91-1.80Ma,带Ⅱ)是以云杉属、榆属和...     

基于耦合关系的干旱绿洲区农村居民点整理分区研究——以张掖市甘州区为例

以张掖市甘州区为例,利用系统科学理论与方法,研究农村居民点整理与农村社会经济之间的动态耦合规律,并以甘州区18个乡镇为研究单元,构建了农村居民点用地整理分区评价指标体系,利用熵值法确定权重,计算农村居民点整理的综合评价值,运用层次筛选法将研究区划分为5个整理区。研究结果：①甘州区农村居民点与农村社会经济的耦合度演化分为3个阶段：1995—1997年,二者不甚协调;1998—2003年,二者都处于持续、稳定、最佳协调发展状态;2004—2007年,二者处于相对稳定协调状态;目前二者处于不甚协调发展阶段。②农村居民点整理分区包括优先整理区、强化整理区、适度整理区、一般整理区和完善整理区。     

The suitability of using leaf area index to quantify soil loss under vegetation cover

Soil erosion by water under forest cover is a serious problem in southern China. A comparative study was carried out on the use of leaf area index (LAI) and vegetation fractional coverage (VFC) in quantifying soil loss under vegetation cover. Five types of vegetation with varied LAI and VFC under field conditions were exposed to two rainfall rates (40 mm h⁻¹ and 54 mm h⁻¹) using a portable rainfall simulator. Runoff rate, sediment concentration and soil loss rate were measured at relatively runoff stable state. Significant negative exponential relationship (p < 0.05, R² = 0.83) and linear relationship (p < 0.05, R² = 0.84) were obtained between LAI and sediment concentration, while no significant relationship existed between VFC and sediment concentration. The mechanism by which vegetation canopy prevents soil loss was by reducing rainfall kinetic energy and sediment concentration. LAI could better quantify such a role than VFC. However, neither LAI nor VFC could explain runoff rate or soil loss rate. Caution must be taken when using LAI to quantify the role of certain vegetation in soil and water conservation.     

基于水污染物通量的小流域生态补水研究

为改善水质环境,对福建省龙江中下流进行补水效果实验.根据控制断面测得的水质浓度和流量数据,计算水污染物通量.使用该通量评估污染负荷,计算生态补水量.所得污染物通量良好地反映出流域污染状况,实验效果显著,河流水质达到了国家规定标准.     

滨海地区地下水泄流研究进展

20世纪90年代以来出现的对滨海地下水的研究方式取得了有意义的结果.其中W.S.Moore通过对226Ra富集揭示了地下水对海岸水体大量补给的研究以及Jacob、Sun等关于潮夕动力地下水流法的研究对解决环境地质问题具有一定的意义.     

Continual erosion of bare rocks after the Wenchuan earthquake and control strategies

The newly bared rocks created by the Wenchuan earthquake are undergoing continual intensive erosion in the form of detachment and movement of individual grains. Grain erosion is defined as the phenomenon of breaking down bare rocks under the action of insolation and temperature change, detachment of grains from the rockwalls by wind, flow down of grains on the slope under the action of gravity, and accumulation of grains at the toe of the mountain, forming a deposit fan. The Wenchuan earthquake, which occurred in Sichuan on May 12, 2008, caused thousands of avalanches and landslides and left scars on slopes and a huge area of bare rocks. Grain erosion causes flying stones, injured humans and resulted in numerous slope debris flows. The process of grain erosion and strategies to limit the erosion were studied by field investigations and field experiments. According to these field investigations and field studies, the most serious grain erosion occurs in spring and early summer when it is very dry. Rocks are broken down to grains under the action of insolation and temperature change. Then, wind blows the grains from the bare rock down slope. Experimental results showed that the amount of grains blown down by wind per area of rock surface per unit time is proportional to the fourth power of the wind speed. However, the size of the grains blown down by wind increases linearly with the wind speed. An experiment proved that grain erosion can be controlled with two moss species. Moss spores were mixed with clay suspension and splashed on bare rocks. The moss species germinated on the rock surface in one month and greened the bare rocks in two months. The moss layer protected the rocks from insolation and mitigated the effects of temperature change, thus effectively mitigated grain erosion.