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WU Guanghui YUAN Yajuan HUANG Shaoying Thomas Matthew Vandyk XIAO Yang CAI Quan LUO Bingxu 《《地质学报》英文版》2018,92(1):74-88
Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of a large conjugate strike-slip fault system from the intracratonic Tarim Basin, NW China. Within our study area, "X" type NE and NW trending faults occur within CambrianOrdovician carbonates. The dihedral angles of these conjugate faults have narrow ranges, 19° to 62° in the Cambrian and 26° to 51° in the Ordovician, and their modes are 42° and 44° respectively. These data are significantly different from the ～60° predicted by the Coulomb fracture criterion. It is concluded that:(1) The dihedral angles of the conjugate faults were not controlled by confining pressure, which was low and associated with shallow burial;(2) As dihedral angles were not controlled by pressure they can be used to determine the shortening direction during faulting;(3) Sequential slip may have played an important role in forming conjugate fault intersections;(4) The conjugate fault system of the Tarim basin initiated as rhombic joints; these subsequently developed into sequentially active "X" type conjugate faults; followed by preferential development of the NW-trending faults; then reactivation of the NE trending faults. This intact rhombic conjugate fault system presents new insights into mechanisms of dihedral angle development, with particular relevance to intracratonic basins. 相似文献
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Tropical cyclone(TC) genesis over the western North Pacific(WNP) is analyzed using 23 CMIP5(Coupled Model Intercomparison Project Phase 5) models and reanalysis datasets. The models are evaluated according to TC genesis potential index(GPI). The spatial and temporal variations of the GPI are first calculated using three atmospheric reanalysis datasets(ERA-Interim, NCEP/NCAR Reanalysis-1, and NCEP/DOE Reanalysis-2). Spatial distributions of July–October-mean TC frequency based on the GPI from ERA-interim are more consistent with observed ones derived from IBTr ACS global TC data. So, the ERA-interim reanalysis dataset is used to examine the CMIP5 models in terms of reproducing GPI during the period 1982–2005. Although most models possess deficiencies in reproducing the spatial distribution of the GPI, their multimodel ensemble(MME) mean shows a reasonable climatological GPI pattern characterized by a high GPI zone along 20?N in the WNP. There was an upward trend of TC genesis frequency during 1982 to 1998, followed by a downward trend. Both MME results and reanalysis data can represent a robust increasing trend during 1982–1998, but the models cannot simulate the downward trend after 2000. Analysis based on future projection experiments shows that the GPI exhibits no significant change in the first half of the 21 st century, and then starts to decrease at the end of the 21 st century under the representative concentration pathway(RCP) 2.6 scenario. Under the RCP8.5 scenario, the GPI shows an increasing trend in the vicinity of20?N, indicating more TCs could possibly be expected over the WNP under future global warming. 相似文献
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XIA Bin YUAN Yajuan ZHANG Yuquan WANG Min XIA Lianze LI He WANG Fangyue ZHANG Hong WU Weiping 《地质学报》2012,86(4)
本文分析了安徽潜山双河大理岩的岩石化学成分、微量元素和稀土元素,并通过锆石“CL”图像,确定变质锆石和变质复合锆石测点位置.定年结果:①变质复合锆石中老核“继承锆石”,共测定32个点,年龄范围在2357～342 Ma:属于元古宙的15个,年龄范围在2357～572 Ma,古生代17个,年龄范围在524～342 Ma;②变质锆石共测定8个点,其中5个点年龄范围在249～234 Ma,相当超高压变质时间,年龄范围在228～221Ma,即退变质时间.前述大量古生代的岩浆碎屑锆石(继承锆石)的存在,表明双河大理岩的原岩泥灰岩,时代不会早于古生代. 相似文献
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对青海共和高寒沙地植被恢复区不同林龄(6年、11年、16年和21年)乌柳(Salix cheilophila)人工防护林根系分布及根量进行了调查、测定,同时测定了土壤有机质含量的垂向变化。结果表明:①不同林龄乌柳林根系主要由中根和细根构成,其数目占土壤剖面根系总数的90%以上,其中又以直径小于2.0mm细根所占比例最高,细根占剖面根系总数的50%以上;②各林龄乌柳根系在0~50cm土层分布较为集中,在30cm以下土层,根量随深度的增加逐渐减少,6年生乌柳林根系垂直分布在0~130cm,20年生乌柳可达200cm,随植被恢复时间的增长,各林龄根量显著增加(p0.05);③各林龄乌柳林有明显发达的垂直主根,属典型的垂直状根系,随植株不断生长,根系表现出深根性;④以不同深度根系重量作为解释变量,以土壤有机质含量作为响应变量,回归结果显示不同林龄乌柳林根系重量显著影响土壤有机质含量(p0.001),这也为评价沙地植被改良土壤功能提供了依据。 相似文献
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非饱和土壤水分运动参数空间变异性研究进展与展望 总被引：7，自引：0，他引：7
非饱和土壤水分运动参数的空间特征是科学认识大尺度土壤水分动态变化的基础和先决条件。在参考国内外大量文献的基础上,对非饱和土壤水分运动参数的研究进展从模型研究到空间尺度研究进行了分析与评述,指出机理模型研究是未来土壤水分运动参数空间变异性研究的方向,而尺度研究目前研究的精度不够;在对土壤水分运动参数的空间变异性研究各类方法分析和归纳后,指出土壤水分运动参数变异性研究的方法包括直接测定方法和间接估计方法两种,并对各种方法的优缺点及适用条件进行了总结;最后指出土壤水分运动参数空间变异性研究存在的问题主要集中在土壤水分运动参数的空间变异性结果的标准化问题和不同尺度土壤水分运动参数的相互转化等问题。 相似文献
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清洁能源的开发利用已成为当前能源发展的重要途径。为了客观评价赤峰市太阳能资源的储量与开发潜力,利用赤峰市14个国家气象观测站1986—2015年的日照时数资料,采用GIS技术和气候学方法,分析了当地太阳能资源的储量和稳定程度。结果表明:赤峰市太阳能资源储量丰富,年总辐射量在5600.78~6262.45 MJ/m2,平均为6025.16 MJ/m2,属于太阳能资源很丰富区且非常稳定,但太阳能资源的空间差异非常显著,特别在西部和北部的多山地区表现尤为明显。基于地形的太阳能资源开发适宜性区划分析表明,次适宜开发的面积最高达41.4%,最适宜和次适宜开发的总面积占全市面积的76.8%。同时考虑开发建设成本及环境保护因素,适合太阳能开发建设的草地和裸地,在最适宜和次适宜开发利用类别中占比分别达26.4%和30.7%,因此,赤峰市太阳能资源开发利用潜力巨大。 相似文献
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针对大比例尺地形图质量检验工作中外业工作占比大、检验效率低的状况,提出了利用车载移动测量系统进行大比例尺地形图质量检验,设计了一套新的检验工作流程,并通过与常规检验方式的比较,验证了新技术应用于质检工作中的可行性和有效性,为建立高效率的质检模式提供了全新思路。 相似文献