A 2500-year sea level change record in Fildes Peninsula, Antarctica

A detailed record of sea level changes during the last 2500 years is preserved in the northernwest coast of Fildes Peninsula in Antarctica. Fourteen marine alga layers were deposited in the beach with an altitude of 2.80 m, and one diatom layer deposited in the ancient lake on the terrace with an altitude of 6.84 m. A radiocarbon age of 695±70 aBP was obtained for the modern marine alga, and the age was used in correction for the carbon reservoir effect of the marine alga. Sea level fell 4.98 m from the 4th century B.C. to the early 13th century, at an average of -0.31 cm/a, then rose about 0.78 m during the early 13th to the middle 18th century, at an average of 0.14 cm/a. It has risen about 0.16 m since the middle 18th century, at an average of 0.07 cm/a.     

20世纪上半叶“扬黛抑钗”审美倾向浅探--钗黛形象接受史研究之三

“扬黛抑钗”的审美倾向贯穿于20世纪上半叶的四个历史阶段并各有特色，它鲜明地折射出每个时期的时代意识。     

华北克拉通恒山地区晚太古代变质火山岩的地球化学特征及构造意义

对恒山地区出露的变质火山岩开展岩相学、地球化学、锆石U-Pb年代学和Hf同位素研究,旨在确定其形成时代,探讨岩石成因及地球动力学意义。锆石U-Pb定年结果表明,这些变质火山岩喷发于新太古代晚期(2508±20Ma)。地球化学分析结果显示,恒山变质火山岩由变质玄武岩和变质玄武安山岩组成,SiO₂(45.51%～62.67%)、FeO_T (4.43%～15.72%)和MgO (3.75%～8.14%)含量变化幅度大,是幔源岩浆经单斜辉石、角闪石和磁铁矿分离结晶的产物。这些变质火山岩富集轻稀土(LREE)和大离子亲石元素(LILE),亏损重稀土(HREE)和高场强元素(HFSE),具有相对高的Th含量和Th/Yb比值,呈现钙碱性岛弧火山岩的特征。结合不相容元素比值Nb/Yb,Zr/Yb和(Nb/La)_N的特点,推测其来源于俯冲带具流体交代特征的富集地幔源区。结合区域构造背景,推断恒山变质火山岩形成于新太古晚期大陆弧环境。     

A new Euprox from the Late Miocene of Yuanmou,Yunnan Province,China,with interpretation of its paleoenvironment

The Yuanmou Basin of Yunnan Province is a hotspot for the research of early homind evolution and its environmental background.During the implementation of the Program“Research of the Origin and Evolution of Early Man and Its Environmental Baqckground” from 1998 to 2001,a huge quantity of hominoid and mammal fossils were collected.The present report systematically describes an Euprox robustus sp.nov.identified during the recent laboratory work on the collected material.Euprox is a group of earliest cervids with true antlers.The new species is the third one of the genus discovered in China.Judged by its morphologic characteristics,the new species feed on juicy and tender leaves of dicotyledon.It implies that the vegetation of its epoch in the Yuanmou Basin is a kind of southern subtropical evergreen forest and the climate is humid and temperate with evident seasonality.The latter is mostly influenced by the monsoon and secondly by the latitude.     

Initial organic geochemical investigation on Late Neoproterozoic-Early Cambrian sediments in the Yangtze region, China

Totally 19 samples of typical Upper Proterozoic-Lower Cambrian sedimentary rocks were collected and analyzed for an organic geochemical investigation. Almost all these rocks have high TOCs, super-maturities and similar biomarker distribution. As an exception, however, the Sinian Nantuo Tillite shows much lower TOCs and little phytane and pristane in comparison with those in other strata, which implies a very faint photosynthetic process, and a restricted euphotic zone and quite limited sunlight within the sedimentary water column during the Sinian glaciation age in the western Yangtze region providing an evidence for palaeo-oceanic environment of the Neoproterozoic Snowball Earth age.     

Triassic U-Pb age for zircon from granites in the Tonghua area and its response to the Dabie-Sulu ultrahigh-pressure collisional orogenesis

Single-grain zircon U-Pb dating was carried out to constrain the emplacement timing of granitic plutons at Chaxinzi, Xiaoweishahe and Longtou in the Tonghua area, south of Jilin Province. The results show that these plutons formed in the Triassic with ages of 203—217 Ma. Geological and geochemical characteristics indicate that the plutons are composed of quartz diorite and granite. The former was derived from partial melting of mafic lower crust, whereas the latter originated from thickened crust with garnet as the residue in the source. It appears that protoliths of these two types of granitits are different although they have the same emplacement age. Considering that these plutons are petrologically different from the coeval granites in the Xingmeng (Xing‘an-Mongolian) to Jihei (Jilin-Heilongjiang) orogenic belt in the north, it is suggested that their formation was related to the Dabie-Sulu ultrahigh-pressure collisional orogenesis since their ages are only 10—20 Ma younger than timing of the ultrahigh-pressure metamorphism, but comparable to that of the first rapid exhumation of the ultra-high-pressure metamorphic rocks and the emplacement of the post-collisional granites.     

吐哈盆地三叠纪孢粉地层学及古气候特征

吐哈盆地三叠系划分为韭菜园组、烧房沟组、克拉玛依组和黄山街组，通过对三叠纪地层的孢粉分析，建立了该盆地的四个孢粉组合带，Limatulasporites—Tae－niaesporites—Alisporites组合带、Aratrisporites—Punctatisporties组合带、Punc－tatisporites—Calamospora组合带和Cycadopites—Lophotriletes—Protoconiferus组合带。依据孢粉的演化得出吐哈盆地三叠纪的古气候为早期的干旱温暖到晚期的潮湿炎热。     

宇宙尘埃流入量与地球气候冷暖关系分析

宇宙尘埃流入量的多少具１０万年的周期变化。宇宙尘埃流入量增加，地球气候变暖，出现间冰期环境；当宇宙尘埃流入量减少，地球气候变冷，出现冰期环境，这是由于宇宙法埃对短波辐射和长波辐射的热效应不同所致。     

袁世凯与晚清宪政改革——兼谈袁世凯与宫廷各派之间的关系

袁世凯不仅促成了清廷预备立宪,而且还在预备立宪的过程中,做了一些别人做不到的事情。袁世凯在直隶试行立宪政治与改革,实际上是配合中央的宪政改革而进行的,其目的是为地方仿行立宪作出表率。尤其地方自治的实行,为接受新式教育的绅商活跃于各级地方政府的政治舞台创造了条件,有利于改变传统的地方和基层权力结构,使地方政治体制逐渐发生转型,朝着民主政治的方向发展。袁世凯的所作所为对近代中国政治的近代化起了一定的推动作用。     

济阳坳陷上第三系储层特征及天然气藏形成条件分析

济阳坳陷上第三系是胜利油田的主要产油气层段之一，也是今后进一步进行天然气勘探开发工作的主力目的层位。本文从上第三系储层的类型及其展布规律、岩性、储集物性、微观孔隙结构等方面，详细分析了天然气储层的特征。并在此基础上，讨论了天然气藏的形成条件及天然气富集规律。研究表明，天然气对储层储集物性的要求比石油更具广泛性；天然气藏的形成除必须具备一定的储层条件外，更重要的是受控于生成运移条件、盖层条件及一定构造背景等。