Sm-Nd and Sr Isotope Geochemistry of Hydrothermal Scheelite from the Zhazixi W-Sb Deposit,Western Hunan     

PENG Jiantang  ZHANG Dongliang  HU Ruizhong  WU Mengjun  LIN Yuanxian 《地质学报》2008,82(11)

  相似文献   

Role of the oceanic channel in the relationships between the basin/dipole mode of SST anomalies in the tropical Indian Ocean and ENSO transition     

Xia Zhao  Dongliang Yuan  Guang Yang  Hui Zhou  Jing Wang 《大气科学进展》2016,33(12):1386-1400

The relationships between the tropical Indian Ocean basin(IOB)/dipole(IOD) mode of SST anomalies(SSTAs) and ENSO phase transition during the following year are examined and compared in observations for the period 1958–2008.Both partial correlation analysis and composite analysis show that both the positive(negative) phase of the IOB and IOD(independent of each other) in the tropical Indian Ocean are possible contributors to the El Nio(La Nia) decay and phase transition to La Nia(El Nio) about one year later. However, the influence on ENSO transition induced by the IOB is stronger than that by the IOD. The SSTAs in the equatorial central-eastern Pacific in the coming year originate from subsurface temperature anomalies in the equatorial eastern Indian and western Pacific Ocean, induced by the IOB and IOD through eastward and upward propagation to meet the surface. During this process, however the contribution of the oceanic channel process between the tropical Indian and Pacific oceans is totally different for the IOB and IOD. For the IOD, the influence of the Indonesian Throughflow transport anomalies could propagate to the eastern Pacific to induce the ENSO transition. For the IOB, the impact of the oceanic channel stays and disappears in the western Pacific without propagation to the eastern Pacific.  相似文献   

青藏高原祁漫塔格古生代以来主要岩浆活动及其意义     

刘栋梁  李海兵  孙知明  裴军令  王焕  潘家伟  王猛 《地质通报》2016,35(12):2014-2026

采用LA-ICP-MS方法对青藏高原祁漫塔格山西部枯草沟地区花岗岩和闪长岩进行锆石U-Pb测年,获得405.7±1.3Ma、420.8±1.6Ma、423.9±1.5Ma和421.0±1.7Ma四个年龄,属于晚志留世—早泥盆世。这些锆石具有高Th/U值,是典型的岩浆锆石,其结晶年龄代表岩石形成年龄。综合统计目前已有锆石U-Pb年龄数据表明,该地区主要存在2期岩浆活动:350~500Ma和200~350Ma,分别对应早古生代和晚古生代—早中生代。祁漫塔格早古生代岩浆活动年龄数量占统计的60%以上,为主要岩浆活动期,主要分布于祁漫塔格北部和西部。东昆仑晚古生代—早中生代的岩浆约占古生代以来岩浆总量的77%以上,为东昆仑主要岩浆活动期。祁漫塔格晚古生代—早中生代岩浆活动主要分布于其东南部,靠近东昆仑山,暗示其可能受东昆仑主要岩浆活动的影响。以上结果暗示,早古生代期间祁漫塔格洋的活动性强于东昆仑洋的活动性,祁漫塔格和东昆仑可能自晚古生代以来才逐步形成统一的造山带。  相似文献   

Recent changes in the active layer thickness across the northern hemisphere   总被引：1，自引：0，他引：1  

Dongliang Luo  Qingbai Wu  Huijun Jin  Sergey S. Marchenko  Lanzhi Lü  Siru Gao 《Environmental Earth Sciences》2016,75(7):555

  相似文献   

青藏高原地面感热及其异常的诊断分析   总被引：24，自引：2，他引：22  

李栋梁  李维京  魏丽  钟海玲  吕兰芝  季国良 《气候与环境研究》2003,8(1):71-83

利用青藏高原主体60个地面气象观测站1961～2000年历年各月本站气压、地面气温、风速、地表温度等资料,计算了高原地面拖曳系数CD和地面感热通量.通过主成分分析、主值函数和功率谱分析等方法,对各季代表月CD系数和地面感热通量的基本气候特征,以及地面感热通量异常变化的空间结构和时间演变趋势作了较系统的诊断研究.结果表明:利用40年资料计算的拖曳系数与地面感热通量可以较好的反应青藏高原下垫面感热的基本气候特征,即高原CD系数东南部大,西北部小;冬季大,夏季小.多年平均高原地面感热通量仅在冬季小范围出现弱的负值,其余季节感热均为正值.感热通量大的地方其年际变化也大,其年际异常的主要空间型,第一是南北差异,第二东西差异,第三为高原主体及东部地区与外围的差异.其在年际变化中存在明显的10年际以上变化趋势,具体表现在1961～2000年期间,冬季高原北部和西部地区地面感热有减弱趋势,而高原中部和东南部呈明显的上升趋势.夏季高原主体及东部地区感热通量不断加强,而高原西部地区则相反.春、夏、秋三季均以13年以上的长周期振荡为主,冬季第一主分量表现为准3年的短周期变化.    相似文献   

Co-seismic and cumulative offsets of the recent earthquakes along the Karakax left-lateral strike-slip fault in western Tibet   总被引：3，自引：0，他引：3  

Haibing Li  Jérôme Van der WoerdZhiming Sun  Jialiang Si  Paul Tapponnier  Jiawei Pan  Dongliang Liu  Marie-Luce Chevalier 《Gondwana Research》2012,21(1):64-87

The 400 km-long Karakax left-lateral strike-slip fault is the westernmost segment of the Altyn Tagh fault. It separates northwestern Tibet to the south from the Tarim basin to the north. The western section of the Karakax fault exhibits clear co-seismic surface ruptures of past large earthquakes. Geomorphic offset measurements from the field and high-resolution Ikonos images along 1.5 km across the Sanshiliyingfang fan and along 55 km of the fault, range from 3 to 28 m, with distinct clusters at 6 ± 2(3), 14 ± 2, 19 ± 2 and 24 ± 3 m. The cluster of the smallest offsets around 6 m (full range from 3 to 10 m) distributed over a minimum length of 55 km, is attributed to the last largest surface rupturing event that testifies of the occurrence of a magnitude Mw 7.4-7.6 earthquake along the Karakax fault. We interpret the other offset clusters as the possible repetition of similarly sized events thus favoring a characteristic slip model for the Karakax fault. In a 3 m-deep trench dug across the active trace of the fault we can identify the main rupture strands of the last and penultimate events. The penultimate event horizon, a silty-sand layer, has been radiocarbon dated at 975-1020 AD (AMS ¹⁴C age). It is proposed that large Mw 7.4-7.6 events with co-seismic slip of about 6 m rupture the Karakax fault with a return time of about 900 years implying an average slip-rate of about 6-7 mm/years during the late Holocene. These results suggest that the Karakax fault is the largest left-lateral strike-slip fault at the rim of northwestern Tibet accommodating eastward movement of Tibet due to the India-Eurasia collision.  相似文献   

柴达木西部地区新生代主控断裂演化过程及其意义   总被引：2，自引：0，他引：2  

李仕远  王亚东  张跃中  方小敏  王九一  刘栋梁 《地质科学》2010,45(3):666-680

基于主干地震剖面的解释结果,本文探讨了柴达木西部地区新生代主控性断裂的活动模式、活动时间及空间演化过程。结果表明,断裂演化明显存在两个大的旋回:路乐河组—下干柴沟组上段沉积期间(约54～31 Ma)和下油砂山组沉积至今(约22 Ma至今);其中第2个构造期断裂活动强烈,尤其是狮子沟组沉积以来(约8 Ma至今),中部及北部区域北西西向断裂开始大规模逆冲活动,反映了盆地晚期强烈变形过程。断层生长指数定量分析结果与其空间演化过程相吻合,共同记录了印度—欧亚板块碰撞远程效应控制下的柴达木盆地在新生代具有阶段性变形特征,从而为青藏高原东北部分阶段隆升模式提供了新的证据。  相似文献   

东亚副热带急流的空间结构及其与中国冬季气温的关系   总被引：5，自引：1，他引：4  

姚慧茹  李栋梁 《大气科学》2013,37(4):881-890

本文利用1950～2012 年NCEP/NCAR 逐月再分析风场资料和中国542 个台站逐日观测资料研究东亚副热带急流(EAJ)的空间结构及其与中国冬季气温的关系。结果表明,东亚副热带急流在空间呈不规则管状结构,冬季急流体积最大,垂直厚度范围自500 hPa 至100 hPa;夏季急流体积最小,仅存在于200 hPa 附近。急流管在秋、冬、春季略呈西南—东北走向,在夏季呈西—东走向。不同高度上的最大风速轴线在南北方向的移动不尽一致,春、秋季低层风速轴比高层偏北。东亚急流管不同区域下方的垂直运动及其年变化存在差异。冬季东亚副热带急流强度与同期中国气温关系密切,特别是高原上空的急流越强时,中国大部分地区冬季气温偏低。  相似文献   

桃源文化旅游探究——以常德桃花源为例     

黄少辉  张冬良  陈波  刘苑婷  詹伟芳 《热带地理》2011,31(1)

从解读陶渊明《桃花源记》入手,通过大量文献资料的查阅,对桃源是否存在及其发源地的南、北之争等问题进行历史脉络的梳理和探讨,提出桃源文化旅游的概念。对桃源文化旅游资源进行分类和对比,认为桃源文化的核心是桃源意境,即仙化田园,其由村民、村庄和村田3村要素构成,常德桃花源是我国历史最久、文物价值最高、保存规模最大的桃源文化遗存,在我国桃源文化中具有代表性。通过对桃源意境与乡村旅游金字塔模型的对比分析,认为从发生的年代性和内涵的一致性看,桃源意境是乡村旅游的原型;为保护和弘扬民族传统文化,将常德桃花源作为非物质文化传承的载体并申报国家非物质文化遗产具有现实和科学意义。最后,以常德桃花源为例,探讨如何建设大桃花源和实施桃源常德区域旅游发展战略以及打造常德桃源文化旅游品牌。  相似文献   

Effects of sunspot cycle length and CO2 on air temperature along Qinghai-Xizang railway and air temperature’s trend prediction     

Li  Dongliang  Guo  Hui  Wang  Wen  Wei  Li 《中国科学:地球科学(英文版)》2004,47(1):131-141

There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (T_rw) from 1935 to 2000 are constructed. The investigation is suggested that: T_rw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 15-year lagged concentration of atmospheric carbon dioxide (CO₂), and the correlation coefficients between them are -0.76 (SCL) and 0.88 (CO₂), respectively. The future SCL is predicted by the model of average generated function constructed with its main cycles of 76a, 93a, 108a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21st century, and then it could be becoming shorter in the second half of the 21st century. Based on the natural change of SCL and the effect of double CO₂ concentration, inrw in the 21st century is forecasted. It could warm up about 0.50°C in the first half of the 21st century compared with the last decade of last century. The mean maximum air temperature could be likely about 0.20°C in July and from 0.40°C to 1.10°C in January. The annual air temperature difference would likely reduce 0.3–1.00°C. The probability of above predictions ranges from 0.64 to 0.73.

  相似文献