This work deals with the characteristics of mantle branch structure in western Shandong Province, China, with respect to the distribution characteristics and ages of the regional strata, the development of ring-like a...This work deals with the characteristics of mantle branch structure in western Shandong Province, China, with respect to the distribution characteristics and ages of the regional strata, the development of ring-like and radial faults, the development of gently inclined detachment-slip structures in the axial part, mantle-source magmatic activities, regional petrology, petrochemistry and isotope geology. The study indicated that the N-W sharply plunged ductile shear zone in the region of western Shandong cuts through the mantle rocks detached from the deep-seated North China mantle sub-plume, hence leading to unloading in response to depressurization and thereafter the formation of anatexis magma. The intense and complete magmatic evolution series not only manifests a variation trend of alkalinity of magma from high to low and its intrusive depth from deep to shallow, but also reflects that the wall-rock alteration shows a general evolution trend from strong to weak. The evolution of mantle structure played an important role in controlling endo-mineralogenesis, accompanied with the rise of the country rocks. As a result, typical mantle branch structures were formed as observed in western Shandong. At the top of the mantle branch structure was developed an obvious detachment-tilt fault block, and some endogenic ores, at the same time, were uplifted onto the shallow levels.展开更多
基于NCEP再分析资料的月平均500 h Pa高度场、NOAA月平均海温资料和山东省121个测站逐月降水资料,对1961—2015年山东省夏季降水与赤道中东太平洋海温对应关系的年代际变化进行研究。结果表明,山东省夏季降水在1970年代中期以及1980年...基于NCEP再分析资料的月平均500 h Pa高度场、NOAA月平均海温资料和山东省121个测站逐月降水资料,对1961—2015年山东省夏季降水与赤道中东太平洋海温对应关系的年代际变化进行研究。结果表明,山东省夏季降水在1970年代中期以及1980年代末、1990年代初发生了明显的转变。其中,在1970年代中期以前,山东省夏季降水量为线性减少趋势,总量偏多,而在1990年代以后,无明显变化趋势。山东省夏季降水与赤道中东太平洋前期冬季海温的关系在转变前后有明显差异:在1970年代中期之前,二者为反位相关系;1990年代之后,二者转为同位相关系。此外滑动相关结果也显示,1990年代以前,山东省夏季降水与Ni1o3区前期冬季海温为负相关关系,1990年代之后,二者为正相关关系。进一步研究发现,山东省夏季降水与西太平洋副热带高压之间的相关关系也发生了年代际变化:在前一时期,山东省夏季降水偏多年份的水汽主要来自东亚夏季风的输送;在后一时期,山东省夏季降水偏多的年份水汽主要来自El Ni1o次年夏季副热带高压西侧偏南气流的输送。展开更多
基金This research project was financially supported jointly by the NationaNatural Science Foundation of China (Grant No. 40272088), theLarge-scale Geological Survey in China (No. 2000110100038) and theCentral Mining Funds (2003-20).
文摘This work deals with the characteristics of mantle branch structure in western Shandong Province, China, with respect to the distribution characteristics and ages of the regional strata, the development of ring-like and radial faults, the development of gently inclined detachment-slip structures in the axial part, mantle-source magmatic activities, regional petrology, petrochemistry and isotope geology. The study indicated that the N-W sharply plunged ductile shear zone in the region of western Shandong cuts through the mantle rocks detached from the deep-seated North China mantle sub-plume, hence leading to unloading in response to depressurization and thereafter the formation of anatexis magma. The intense and complete magmatic evolution series not only manifests a variation trend of alkalinity of magma from high to low and its intrusive depth from deep to shallow, but also reflects that the wall-rock alteration shows a general evolution trend from strong to weak. The evolution of mantle structure played an important role in controlling endo-mineralogenesis, accompanied with the rise of the country rocks. As a result, typical mantle branch structures were formed as observed in western Shandong. At the top of the mantle branch structure was developed an obvious detachment-tilt fault block, and some endogenic ores, at the same time, were uplifted onto the shallow levels.
文摘基于NCEP再分析资料的月平均500 h Pa高度场、NOAA月平均海温资料和山东省121个测站逐月降水资料,对1961—2015年山东省夏季降水与赤道中东太平洋海温对应关系的年代际变化进行研究。结果表明,山东省夏季降水在1970年代中期以及1980年代末、1990年代初发生了明显的转变。其中,在1970年代中期以前,山东省夏季降水量为线性减少趋势,总量偏多,而在1990年代以后,无明显变化趋势。山东省夏季降水与赤道中东太平洋前期冬季海温的关系在转变前后有明显差异:在1970年代中期之前,二者为反位相关系;1990年代之后,二者转为同位相关系。此外滑动相关结果也显示,1990年代以前,山东省夏季降水与Ni1o3区前期冬季海温为负相关关系,1990年代之后,二者为正相关关系。进一步研究发现,山东省夏季降水与西太平洋副热带高压之间的相关关系也发生了年代际变化:在前一时期,山东省夏季降水偏多年份的水汽主要来自东亚夏季风的输送;在后一时期,山东省夏季降水偏多的年份水汽主要来自El Ni1o次年夏季副热带高压西侧偏南气流的输送。
