共查询到11条相似文献,搜索用时 93 毫秒
1.
SHANGQinghua 《科学通报(英文版)》2004,49(24):2613-2619
The Zhesi (Jisu) Formation of the Middle Permian in Nei Mongol (Inner Mongolia) was commonly considered to be a shallow marine sequence. Here I report the radiolarians found in the argillite bed of that formation in Zhesi and Xilinhot areas. This fact indicates a deep marine sedimentary facies persisted during the Middle Permian, and suggests that the ocean between the North China Block and Siberian Craton was not closed until the Late Guadalupian. The suture of this two blocks is probably extends along the Linxi ophiolite belt, south of the Hegenshan ophiolite belt. 相似文献
2.
许武成 《西华师范大学学报(哲学社会科学版)》2008,29(4)
基于月降水和月平均气温资料,分析了川中丘陵区近50年降水和气温的变化特征及其与太平洋年代际振荡指数(PDOI)的关系.结果表明,川中丘陵区气候存在明显的年代际趋势和突变特征.相关分析和独立样本T检验表明,川中丘陵区夏季气温、年平均气温和秋季降水量与年PDOI均有显著的相关关系,PDO冷位相(1977年以前)对应着高温、多秋雨,而PDO暖位相(1977年以后)对应着夏季和年均温下降,秋季雨水减少. 相似文献
3.
Linear relationship between the interdecadal and interannual variabilities of North China rainfall in rainy season 总被引:9,自引:2,他引:7
LURiyu 《科学通报(英文版)》2003,48(10):1040-1044
Interdecadai and interannuai timescales are dominant in the North China rainfall in rainy season (July and August). On the interdecadai timescale, the North China rainfall exhibited an abrupt decrease at the end of 1970s. In this study, we examined the effect of this abrupt rainfall decrease on the association between rainfall and circulation on the interannuai timescale, and found that the interdecadal variation does not change the physical mechanism responsible for the interannuai variation of North China rainfall.There is a linear relationship between the interdecadai and interannuai variabilities of North China rainfall in rainy season. 相似文献
4.
Correlations between North Atlantic Oscillation Index in winter and eastern China Flood/Drought Index in summer in the last 530 years 总被引:4,自引:0,他引:4
FU Congbin ZENG Zhaomei 《科学通报(英文版)》2005,50(21):2505-2516
The time series of winter North Atlantic Oscillation Index (NAOI) in the period of 1429-1983 developed by Glueck and summer Flood/Drought Index (FDI) of eastern China in the period of 1470-1999 from I00 stations are used in this paper to study the potential impact of North Atlantic Oscillation on the climate in China. The analysis has explored some significant lag correlations between FDI and NAOI. The maximum positive correlation coefficients between NAOI and area-mean FDI in eastern and northern China lagging 2-3 years reach at 0.001 significance level, and while there are also negative correlation between NAOI and FDI in central and southern China at significance level of 0.05-0.01. The correlation between FDI and NAOI is time-dependent, i.e. the correlation coefficients between two indices vary from period to period. The highest correlation appeared in the period of 1636-1742, around the Little Ice Age, with the significant level of far above 0.001. The second significant period was from 1951 to 1999, at the level of 0.005-0.002. Both the power spectrum analysis and Morlet wavelet transformation have presented an interesting phenomenon: the area-mean FDIs in eastern and northern China share almost the same oscillation periods with NAOI in the inter-annual, decadal and centurial scales' oscillations, i.e. 4-5, about I0, 20-30, around 50 and 80-100 years, etc. The Mann-Kendall Rank Statistic test reveals the significant trend and decadal abrupt changes in the series of area-mean FDIs in eastern and northern China in the past 530 years, while the NAOI in the past 400 years, did not show such trend at the significance level, but presented more frequent changes than those of FDI in China. This difference is perhaps due to the fact that the amplitude of the extremes of reconstructed NAOI series is less than that from instrumental records. 相似文献
5.
Interannual variation of North China rainfall in rainy season and SSTs in the equatorial eastern Pacific 总被引:4,自引:2,他引:4
LU Riyu 《科学通报(英文版)》2005,50(18):2069-2073
The rainfall in North China during rainy season (July and August (JA)) exhibits a strong interannual variability. In this study, the atmospheric circulation and SST anomalies associated with the interannual variation of JA North China rainfall are examined. It is found that on the interannual timescale, the JA North China rainfall is associated with significant SST anomalies in the equatorial eastern Pacific, and the North China rainfall and SST anomaly in the equatorial eastern Pacific correspond to the similar variation of the upper-level westerly jet stream over East Asia. A possible mechanism is proposed for the influence of the SST anomalies in the equatorial eastern Pacific on the North China rainfall. 相似文献
6.
CASHL华东北三省高校文献传递服务的现状与思考 总被引:4,自引:1,他引:3
周海花 《科技情报开发与经济》2008,18(13):77-78
对CASHL华东北三省高校文献传递服务现状进行了分析,指出了存在的问题,并提出了相应的对策。 相似文献
7.
Shuangying Li Zaifei Ji Song Wang Cheng Cheng Lixiang Guo Dongdong Yang Hao Niu 《科学通报(英文版)》2014,59(7):645-650
Late Carboniferous fossils (such as Boultonia? sp., Tabulata, and spiriferoid specimens with smooth she/Is), bioclastic material (such as crinoid stems and sponge fragments), and Late Ordovician microfossils of the conodont Belodina have been discovered in the lower part of the strata typically referred to as the Neoproterozoic on the boundary of the provinces of Anhui and Henan in the southern margin of the North China Block. These findings prove that the strata contain macrofossils belonging to the Late Carboniferous, which belonged to a carbonate debris flow deposit that was formed under a carbonate slope environment. The conodont fossils might belong to a detrital deposit. Thus, it is possible to reset the stratigraphic sequences and tectonic attributes belonging to the North Huaiyang tectonic belt and limit the Shouxian fault to the boundary between the Dabie Orogen and North China Block. 相似文献
8.
华北和华南块体古生代至中生代古地磁极移曲线与古纬度的分布变化 总被引:5,自引:0,他引:5
本文是对近年来国内外学者,对华北和华南块体古地磁研究工作的初步总结分析,和对笔者1990年古地磁极移曲线编制工作的补充和修正。在收集整理关于华北和华南块体古生代至中生代古地磁研究成果的基石出上,结合笔者的新成果,按照一定的规则选取部分数据,经统计分析计算,得到两大块体的古地磁极移曲线和古纬度分布变化,据此推导出两大块体的运动形式和北向运动的速率及规模,指出两块体拼合的时限。 相似文献
9.
LA-(MC)-ICPMS U-Pb zircon geochronology and Lu-Hf isotope compositions of the Taihua complex on the southern margin of the North China Craton 总被引:15,自引:0,他引:15
Widely distributed on the southern margin of the North China Craton, the Taihua complex extends roughly in an east-west direction and the relatively complete successions are found in Lushan County, Henan Province. Like many other Archean terranes, the Taihua Complex can be divided into two major lithological units along the Dangze River, namely gneisses series and supracrustal rocks. The former is located on the north side of the river and chiefly composed of TTG gneisses and amphibolites; the latter on the south side of the river is mainly supracrustal rock. Coupled with the previous studies, the results obtained by this study show that the Taihua complex was formed in a large time span from Neoarchean to Palaeoproterozoic. The TTG gneisses and amphibolites are dated at Neoarchean (2794–2752 Ma). The 2.9 Ga and 3.1 Ga zircons in amphibolites could be xenocrysts. In the North China Craton, the 2.8–2.7 Ga old rocks crop out in several areas e.g. western Shandong Province, Jiaodong Peninsula and Lushan area of Henan Province. In addition, 2.8–2.7 Ga detrital zircons or xenocryst zircons have been recognized in Huai’an, Fuping, Wutai areas of North China Craton and also reported in the Early Paleozoic diamondiferous kimberlites in Mengyin and Fuxian. All these age results indicate that the 2.8–2.7 Ga rocks may have been developed much broader region than today’s outcrops. Zircon Hf and whole rock Nd isotopes show that the 2.8–2.7 Ga tectono-thermal event represents an important period of crustal growth with minor ancient crust reworked in the North China Craton. However the formation of supracrustal rocks is limited to 2.2–2.0 Ga in the Palaeoproterozoic time, not the Archaean, as previously believed. Combined with the chronological data of aluminium-rich metamorphic rocks (Khondalite series) on the southern margin of the North China Craton and adjacent areas, it is suggested that the above areas have widely developed Paleoproterozoic passive continental margin environment. 相似文献
10.
Wan YuSheng Miao PeiSheng Liu DunYi Yang ChongHui Wang Wei Wang HuiChu Wang ZheJiu Dong ChunYan Du LiLin Zhou HongYing 《科学通报(英文版)》2010,55(13):1278-1284
This paper reports detrital zircon age distributions of meta-sedimentary rocks of the Gaofan, Hutuo and Dongjiao groups in the Wutai and Dongjiao areas of the North China Craton. Detrital zircons of a quartzite from the Gaofan Group are mainly ~2.5 Ga in age, with some ~2.7 Ga and older. A quartzite pebble from the basal conglomerate of the Hutuo Group is similar in detrital zircon age distribution to the quartzite of the Gaofan Group. For a meta-feldspar-quartz sandstone from the Dongjiao Group, the age of... 相似文献
11.
Disequilibria between 210Po and 210Pb in the upper water and their potential applications as a proxy of particle export and remineralization were examined in the Southern Ocean (station IV3) and the South China Sea (NS44). 210Po was deficit in surface waters but excessive relative to 210Pb in subsurface waters. Good positive correlation between 210Po and particulate organic carbon (POC) indicated deficits and excess of 210Po resulted from particulate organic matter (POM) export and remineralization respecti... 相似文献