甘肃北山孙家岭含钪岩体LA-ICP-MS锆石U-Pb测年及地质意义          下载免费PDF全文

谢燮  赵国斌  杨合群  杨生飞  任华宁  贾健  孙新春  黄增保 《中国地质》2018,45(3):483-492

孙家岭含钪岩体位于哈萨克斯坦板块中星星峡—明水—旱山微板块的雅满苏—红石山—黑鹰山晚古生代裂谷带。岩体侵位于下石炭统白山组,由含斜长石角闪石岩和角闪石岩组成,钪主要赋存于角闪石矿物中。含钪岩体属富铁质超基性岩,全岩成分以高碱、高铝为特征;稀土含量较高,轻稀土略富集,具有明显的负Eu异常;大离子亲石元素(LILE)K、Rb、Ba、Sr、U富集,相对亏损高场强元素(HFSE)Nb、Zr、Hf、Th及P。通过LA-MC-ICP-MS锆石U-Pb测年,首次获得孙家岭含钪岩体中角闪石岩形成于(339.5±2.6)Ma,表明该含矿岩体侵位及矿化作用发生于早石炭世,为裂谷拉张环境下伸展作用的产物。  相似文献   

西秦岭成矿带矿床成矿系列概论     

杨合群  赵国斌  姜寒冰  辜平阳  温志亮  李宗会 《西北地质》2022,(1):114-128

对西秦岭成矿带总结了 11个矿床成矿系列:①早古生代沉积作用有关钼-钒-锰-磷-石煤-石灰岩矿床成矿系列.②晚古生代沉积作用有关铅-锌-铁-磷-石灰岩-白云岩-石膏-煤-黏土-砚石矿床成矿系列.③晚古生代岩浆作用有关铜-铅-锌-锡-铬-饰面超基性岩矿床成矿系列.④中生代沉积作用有关白云岩-石灰岩-煤-油页岩矿床成矿系列...  相似文献   

淹没丁坝群二维水流数值模拟新方法     

许慧  李国斌  尚倩倩  张明 《水科学进展》2014,25(3):407-413

为模拟淹没丁坝群平面二维水流运动,提出了淹没丁坝群二维水流数值模拟新方法并建立了数学模型。新方法的主要实施方案:① 将丁坝视为无厚度坝,用网格线概化丁坝;② 采用新的网格节点布置形式,即水深、流速节点布置于网格界面上,水位节点布置于网格中心,有别于一般交错网格节点布置。模型采用基于结构网格下的有限体积法对方程组进行离散,同时将淹没丁坝坝顶水深代入离散方程中进行求解。采用已有的水槽试验资料,进行了初步验证,模拟了长江下游东流水道已建丁坝群工程实施后河道的流场和水位场,结果表明计算和实测符合较好。  相似文献   

Influence of vegetation factors on biological soil crust cover on rehabilitated grassland in the hilly Loess Plateau, China   总被引：1，自引：0，他引：1  

Jian Zhang  Guobin Liu  Mingxiang Xu  Ming Xu  Norikazu Yamanaka 《Environmental Earth Sciences》2013,68(4):1099-1105

Biological soil crusts (BSCs) perform essential ecosystem functions in arid and semi-arid ecosystems worldwide. The formation, development, and distribution of BSCs are influenced by changes in multiple environmental factors, including changes in the vascular plant community. The influence of changes in vegetation factors on BSC cover in 8-, 12-, and 16-year-old rehabilitated grasslands were studied in the hilly area of the Chinese Loess Plateau. The rate of degradation of BSCs underneath litter (P < 0.01) and the degradation cover of BSCs (P < 0.05) differed significantly between the 8- and 16-year-old successions. Stepwise multiple linear regression analysis showed that the main vegetation factors influencing the dynamics of BSC cover differed among the 8-, 12-, and 16-year-old rehabilitated grasslands. Basal cover, phytomass, and litter cover were the main vegetation factors influencing the dynamics of BSC cover on 8-year-old rehabilitated grassland. Phytomass, litter thickness, and litter cover were the main factors influencing the dynamics of BSC cover on 12-year-old rehabilitated grassland. On 16-year-old rehabilitated grassland, Pielou evenness index, litter thickness, and litter biomass were the main vegetation factors influencing degradation of BSC cover underneath litter, whereas basal cover, litter thickness, and litter biomass were the main vegetation factors influencing the degradation cover of BSCs. At particular stages of herbaceous succession, vegetation factors can have a large influence on changes in the community’s basal cover and litter, which are key factors influencing changes in BSC cover. The degradation of BSCs underneath litter may be a result of complicated eco-physiological processes.  相似文献   

Effect of black locust (<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis>) on soil chemical and microbiological properties in the eroded hilly area of China’s Loess Plateau     

Bing Wang  Guobin Liu  Sha Xue 《Environmental Earth Sciences》2012,65(3):597-607

Black locust (Robinia pseudoacacia) has been widely planted in the Chinese Loess Plateau for soil and water conservation as an important forest species. This study examined variations in topsoil organic C (OC), total N and P (TN and TP), available N, P and K (AN, AP and AK), and soil microbial biomass C, N and P (SMBC, SMBN and SMBP) contents and the activity of urease (URE), α-amylase (ALA), alkaline phosphatase (ALP), catalase (CAT), saccharase (SAC), polyphenol oxidase (PPO) and cellulase (CEL) in loessial soil of black locust with an age sequence of 5, 10 15, 20, 25, 30, 40 and 50 years in Zhifanggou watershed (8.27 km²), Shaanxi Province, Northwest China. Also cultivated fields and 80-year Chinese arborvitae (Platycladus orientalis) were selected for the comparison. The results showed that soil chemical properties, microbial biomasses and soil enzyme activities varied with the restoration age. After 50-year growth of black locust, OC, TN, AN, TP, AK, SMBC, SMBN, SMBP, URE, ALP, SAC and CEL in soil increased by 262, 193, 345, 22, 36, 210, 136, 85, 90, 108, 288 and 36%, respectively, while PPO decreased by 31%. Soil chemical properties of TN and soil microbial biomass of SMBC were linearly correlated with soil enzymes of URE, ALP and SAC. Moreover, nitrogen fixation of black locusts was not evident before it became mature, but more evident after it reached maturity. The results confirmed that black locusts have long-term benefits on the improvement of soil properties as exotic species on the Loess Plateau for the soil properties under black locusts were greatly improved compared to cultivated fields.  相似文献   

New U-Pb isotopic data on the age of metamorphic and igneous rocks of the western margin of the Selenga-Stanovoi orogenic belt     

A. S. Vakh  O. V. Avchenko  N. A. Goryachev  V. I. Gvozdev  V. I. Kiselev  V. G. Khomich  Yanchen Yang  Songqing Ye  Guobin Zhang 《Doklady Earth Sciences》2013,450(2):575-582

New data on the isotopic age of zircons from metamorphic and igneous rocks are given for the Berezitovoe and Kirovskoe deposits located in the eastern margin of the Selenga-Stanovoi orogenic belt. The zircons were studied with the LA-ICP-MS method in the State Key Laboratory of Continental Dynamics, Northwestern University, Sian, Shansi province, People’s Republic of China. The results allowed us to reveal three age epochs in formation of the eastern part of the Selenga-Stanovoi orogenic belt (1.87 Ga; 380–330 Ma; 138–125 Ma), which have significant importance for understanding of the geological structure of the south-eastern framework of the North Asian craton.  相似文献   

Effects of patterned Artemisia capillaris on overland flow velocity under simulated rainfall   总被引：2，自引：0，他引：2  

Guanhua Zhang  Guobin Liu  Guoliang Wang  Yuxia Wang 《水文研究》2012,26(24):3779-3787

Vegetation cover is an important factor for erosion control. Laboratory‐simulated rainfall experiments were conducted to quantify the effectiveness of patchy distributed Artemisia capillaris in retarding overland flow velocity. Simulated storms (60, 90, 120, and 150 mm h^?1) were applied on a bare plot (CK) and four different plant patterns, a banded pattern perpendicular to the slope direction (BP), a single long strip parallel to slope direction (LP), small patches distributed like a checkerboard (SP1), and small patches distributed like a letter “X” (SP2). All treatments had three replicates. Each plot underwent two sets of experiments, intact plant plots and root plots (the above‐ground parts were removed, only roots were reserved), respectively. Results showed that flow velocity increased with rainfall intensity, and the lower slope velocity (V_l) was higher than the upper slope velocity (V_u). The removal of grass shoots increased flow velocity. Compared with bare soil plot, intact plants reduced mean flow velocity by 14%–60%, whereas the reduction declined to <40% for the root plots. BP and both SP treatments performed more effectively than LP in retarding flow velocity, whereas no significant differences were identified between BP and SP. The contributions of A. capillaris shoots and roots to the reductions in flow velocity under different rainfall intensities were different. The shoots made greater contribution of 53%–97% at 60 and 90 mm h^–1, and the roots contributed more (51%–81%) at 120 and 150 mm h^–1. Runoff and sediment rate had significant (p < 0.05) linear correlations with mean flow velocity. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

黑龙江漠河县八里房金矿床地球化学特征及成因     

张国宾  杨言辰  王献忠  张志国  叶松青  李庆录  李向文  李海洋  王庆双 《吉林大学学报(地球科学版)》2013,43(6):1812

八里房金矿床位于黑龙江省漠河县西北部,是一个新发现的金矿床。矿体赋存于闪长岩和中侏罗统额木尔河组长石砂岩中,矿石由含金、黄铁矿的长石砂岩和石英细脉组成。岩石地球化学研究表明：闪长岩稀土总量中到低,富集大离子亲石元素(如K、Rb、Ba)和化学性质活泼不相容元素(如U、Th、Pb),相对亏损高场强元素(如Ta、Nb、P、Sr、Ti),球粒陨石标准化稀土配分模式为轻稀土富集、重稀土亏损的右倾型,具有弱的Eu负异常(δEu平均值为0.8),无Ce异常(δCe=0.9～1.0),元素地球化学性质反映出八里房闪长岩具有岛弧岩浆岩的特征;长石砂岩稀土元素总量(∑REE)变化较大,具弱Eu负异常(δEu平均值为0.8),无Ce异常(δCe=0.9～1.0),为活动边缘砂岩系列。含金石英脉中流体包裹体有气液两相、含CO₂三相和纯CO₂流体包裹体3种类型。气液两相包裹体均一温度为107.9～247.4 ℃,盐度(w(NaCl))为3.05%～8.55%,密度为0.84～1.00 g·cm^-3;含CO₂三相包裹体完全均一温度为269.8～332.7 ℃,盐度为4.41%～10.29%,成矿流体为中低温、低盐度的热液流体体系。基于矿床地质特征、岩石地球化学和成矿流体特征的研究,笔者认为八里房金矿床为造山型金矿床。  相似文献   

用无味变换法求解交会测量及其协方差传播     

李胜全  欧阳永忠  常国宾  金际航  李科 《海洋测绘》2012,(4):38-40

在交会测量中,交会角的测量误差会使得定位结果具有不确定性,定位坐标的均值和协方差用于表示定位结果及其不确定度。首先对基于一阶Taylor级数展开的前方交会测量及其协方差传播进行研究,分析发现该方法仅具有一阶精度,特别是在测量误差较大的场合,该方法精度较低。然后将无味变换方法用于前方交会测量定位问题,使定位精度、协方差传播精度均提高到二阶以上。最后通过数值仿真验证了无味变换方法在定位精度以及协方差传播精度方面的优势。  相似文献   

海上导航信息远程传输监控技术研究与应用     

李科  王智明  李胜全  金际航  常国宾 《海洋测绘》2013,33(1):22-25

将北斗通信技术、船舶自动识别系统技术、航标遥测遥控技术以及GPS差分技术进行有效结合,研制了海上导航信息远程传输监控系统,对我国中、远海海域装有AIS设备的船舶进行跟踪与监控、可疑船舶的辨认、船舶的岸基调度、航标遥测遥控、GPS差分信息远程播发等。相比单一技术的应用,海上导航信息远程传输监控系统不受天气条件限制,无需人员定期出海维护,具有设备集成度高、导航差错率低、功能全面、成本效益好等特点。  相似文献