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81.
本文在系统收集内蒙古林西-东乌旗地区晚古生代-早中生代岩浆岩的年代学、岩石地球化学以及锆石Hf同位素资料基础上,通过分析岩浆岩岩石组合随时空的变化规律,并结合区域地质资料,探讨了中亚造山带东南部洋盆演化和地壳增生等重要地质问题。研究结果表明,二连浩特-贺根山蛇绿岩带南、北两侧晚古生代-早中生代岩浆岩在年代学上显示不同的活动期次,具有不同岩石组合和地球化学特征,指示它们分属于不同的构造岩浆岩带。蛇绿岩带以北晚泥盆世-中二叠世岩浆活动在时间上呈连续分布的特征,并在晚石炭-早二叠世时期达到活动峰值。火成岩构造组合分析表明,晚泥盆世-石炭纪和早-中二叠世岩浆活动分别与二连浩特-贺根山洋盆向乌里雅斯太大陆边缘之下的俯冲和洋盆闭合后俯冲板片断离引起的软流圈上涌造成的区域伸展背景有关。蛇绿岩带以南岩浆活动时间上呈现石炭纪、早-中二叠世、晚二叠世-三叠纪幕式分布特征,各期岩浆活动前锋有随时间向南迁移的趋势。这三期岩浆活动分别与古亚洲洋板片向宝力道岛弧之下的俯冲、板片后撤以及洋盆消失之后古板块的碰撞造山作用有关。锆石Hf同位素分析表明,中亚造山带东南部晚古生代至早中生代时期存在显著的地壳增生;其中二连浩特-贺根山蛇绿岩带以北表现为地壳的垂向增生,以南表现为地壳的侧向增生。 相似文献
82.
83.
南海西南部新生代盆地类型及演化历史 总被引:4,自引:0,他引:4
南海西南部地区发育了多种类型的新生代沉积盆地,各种类型的盆地具有各自的结构特征和演化历史,走滑-周缘前陆盆地-曾母盆地发育了渐新-中中新统层系,晚中新统层系和上新-第四系层系第三套地层,曾母盆地经历了三个发育阶段,拉张剪切盆地-万安盆地发育下第三系-下渐新统层系,上渐新统一中中新统层系和上中新统一第四系层系三套地层,万安盆地经历了四个发育阶段。 相似文献
84.
The Zoige Basin is located in the eastern margin of the Qinghai-Xizang Plateau, in which two cores, RH and RM, have been drilled,
with the depths of 120 m and 310 m respectively. The former with the bottom age of 826 kaB. P. has been divided into 21 stages
according to the multi-proxy analysis, which could be basically compared with the oxygen isotope record of deep-sea core.
The palaeoclimatic and palaeoenvironmental process of the Zoigê Basin over the past 900 kaB. P. is reconstructed, and the
comparison of core RH with the Luochuan Loess record is made. 相似文献
85.
MohammedHazaea HUKe MohammedMattash CHENBing M.O.AI-JabaliAref MohammedAbdussalam 《东北亚地学研究》2004,7(2):181-184
The chemical composition of several thermal springs around Changbaishan area has been investigated. Cenozoic basaltic rocks are widely distributed in Northeast China and geothermal characteristics have been described. About one hundred hot springs exist around Changhaishan Volcano at the border between China and D.P.R.Korea with high temperature about 82~C. The pH values of the spring water range from 6.9 to 7.1 and the total flow rate is about 4.8 L/sec. The chemical composition of the thermal springs is sodium carbonate; the high-mineral contents of thermal water are believed to have medicinal properties. Bathhouses are already built along the hot springs to take the advantage of the supposed healing properties. The high quality of those hot springs is believed to be utilitized for mineral water. The chemical equilibrium temperatures were estimated at about 160℃ based on the Na-K-Ca geochemical thermometer. 相似文献
86.
<正>The Huang Shui River,a main tributary of the Yellow River,crosses a series of tectonically subsided and uplifted areas that show different patterns of terrace formation.The distribution of fluvial terrace of the Huang Shui River is studied through topographic and sedimentologic terrace mapping.Three terraces in the Haiyan Basin,four terraces in the Huangyuan Basin,19 terraces in the Xi'ning Basin(the four high terraces may belong to another river),nine terraces in the Ping'an Basin, five terraces in the Ledu Basin and 12 terraces in the Minhe Basin are recognized.Sedimentology research shows that the geomorphologic and sedimentological pattern of the Huang Shui River,which is located at the margin of Tibet,are different from that of the rivers at other regions.The formation process of the terrace is more complicated at the Huang Shui catchment:both accumulation terrace and erosion terrace were formed in each basin and accumulation terraces were developed in some basins when erosion terraces were formed in other basins,indicating fluvial aggradation may occur in some basins simultaneously with river incision in other basins.A conceptual model of the formation process of these two kinds of fluvial terraces at Huang Shui catchment is brought forward in this paper.First,the equilibrium state of the river is broken because of climatic change and/or tectonic movement,and the river incises in all basins in the whole catchment until reaching a new equilibrium state.Then,the downstream basin subsides quickly and the equilibrium state is broken again,and the river incises at upstream basins while the river accumulates at the subsidence basin quickly until approaching a new equilibrium state again.Finally,the river incises in the whole catchment because of climatic change and/or tectonic movement and the accumulation terrace is formed at the subsidence basin while the erosion terrace is formed at other basins.The existence of the accumulation terrace implied the tectonic subsidence in the sub-basins in Huang Shui catchment.These tectonic subsidence movements gradually developed from the downstream Minhe Basin to the upstream Huangyuan Basin.Dating the terrace sequence has potential to uncover the relationship between the subsidence in the catchment and the regional tectonic at the northeastern Tibetan Plateau. 相似文献
87.
大别山构造带东段杨山组煤的变质演化 总被引:2,自引:0,他引:2
采用地史分析与数值模拟相结合的研究方法,对下石炭统杨山组煤的变质演化历程进行了定性和定量研究。结果表明:杨山组煤的变质作用经历了海西旋回中期和燕山旋回中-晚期两个演化阶段,煤级在第一阶段异常低热古地热场中深成变质作用下达到焦煤,第二阶段却在异常高热古地热场导致的热变质作用下剧增至超无烟煤。在包括研究区在内的大别山构造带北麓,海西旋回中期可能具有冷盆的特征,而燕山旋回中-晚期却表现出热盆的性质。 相似文献
88.
Ignacio Ferreras Alessandro Melchiorri Domenico Tocchini-Valentini 《Monthly notices of the Royal Astronomical Society》2003,344(1):257-261
The age of the Universe has been increasingly constrained by different techniques, such as the observations of type Ia supernovae (SNIa) at high redshift or dating the stellar populations of globular clusters. In this paper, we present a complementary approach using the colours of the brightest elliptical galaxies in clusters over a wide redshift range ( z ≲ 1) . We put new and independent bounds on the dark energy equation of state parametrized by a constant pressure-to-density ratio w Q and by a parameter (ξ) which determines the scaling between the matter and dark energy densities. We find that accurate estimates of the metallicities of the stellar populations in moderate and high-redshift cluster galaxies can pose stringent constraints on the parameters that describe dark energy. Our results are in good agreement with the analysis of dark energy models using SNIa data as a constraint. Accurate estimates of the metallicities of stellar populations in cluster galaxies at z ≲ 2 will make this approach a powerful complement to studies of cosmological parameters using high-redshift SNIa. 相似文献
89.
Polyc·lonal antibodies raised against LHC II isolated from SDS-solubilizedBryopsis corticulans thylakiod membranes by SDS-PAGE, were characterised by double immunodiffusion, Rocket immunoelectrophoresis and antigen-antibody
crossed immunoelectro-phoresis assays showed the antibodies had strong cross-reaction with allB. corticulans LHC II components (even with those which were incubated in boiling water) and showed immunological cross-reactivity with
LHC II polypeptides of spinach and the marine green algaCodium fragile. The results suggested that LHC II of different species had similar antigenic determinants and also conservation of amino
acid sequences of the polypeptides during evolution, and that the antibodies could cross react with apoproteins of D2 proteins (which contain P680) fromB. corticulans, spinach andC. fragile, but not with apoproteins of P700 Chl-proteins. Our results indicated some similarities in primary structure between LHC II of different species, and between
LHC II and D2 proteins of marine green algae and spinach. Our finding that D2 and P700 Chl-proteins are not immunologically related suggested that P700 Chl-proteins and D2 proteins pass through independent evolutionary pathways.
Contribution No 1717 from the Institute of Oceanology, Academia Sinica, This subject was supported by the National Science
Foundation of China. 相似文献
90.
地热勘查孔(探采结合孔)是在矿山钻探施工工艺的基础上进行的探索性施工。着重介绍了福建省泉州市聚龙小镇DZK1地热勘查孔在钻探施工过程中遇到的施工难题以及新技术、新工艺的应用。如大口径单管取心、空压机洗井和活塞洗井相结合的洗井方法、套管的隔级使用、深孔测试钻杆密闭性、深孔磨钻头、在涌水量大的地层钻进等。 相似文献