中国东北全新世干湿状况的演变

通过综合分析植物花粉,沙土埋藏土壤,泥炭形成与发展,沙丘活动历史,黄土状土堆积和黑土发育等多种资料表明,我国东北地区的湿润程度或土壤水分含量在５ｋａ ＢＰ以前的早中全新世较低,中晚全新世不能增加,早中全新世最干燥时段出现的＾１４Ｃ年代９－８ｋａ ＢＰ,中晚全新世湿润时期可能是最近的２ｋａ,近现代气候比过去１０ｋａ平均状况湿润。     

长白山天池火山全新世喷发与岩石地球化学特征

全新世以来长白山天池火山以爆炸式喷发为特点,其喷发物包括空降堆积浮岩、熔结凝灰岩和碎成熔岩,除了极少量粗面质成分（SiO2<65％）,均属于碱流质火山碎屑岩（SiO2＝70%～73％,K2O+Na2O=10%～11%）。火山岩的矿物学（造岩矿物和残余矿物）和主微量元素、SrNd同位素地球化学研究表明,天池火山全新世火山岩与造锥阶段、造盾阶段火山岩是同源（幔源）岩浆演化的产物,全新世火山岩都具有强烈而相似的Eu、Ba、Sr、Ti负异常,指示了岩浆演化主要受斜长石的强烈分离结晶作用控制。     

天桥沟-黄羊川活动断裂带的几何学和运动学特征

依据１ ：５０ ０００ 地质填图资料,对天桥沟—黄羊川活动断裂带晚更新世以来的几何学和运动学特征进行了详细的论述．认为该断裂带可分为逆走滑（ 左旋） 的天桥沟断裂段和正走滑（ 左旋） 的黄羊川断裂段,其主要活动时期是晚更新世,滑动速率为４ ～５ ｍ ｍ／ａ ．全新世早期,该断裂带活动强度逐渐减弱,其最后一次活动的时间为距今０ ．７５９ ×１０４ ～１ ．０２ ×１０４ 年     

用水氡最大变化率法对强震时间作中短期预报

介绍了水氡变化率的物理含义以及变化率动态图象的生成方法,强震前在动态图象上存在着变化率≥０．０６高值异常区,异常区中心的最大变化率随时间有规律地演化,且与发震时间有着良好的统计关系。据此提出４个时间预测指标。检验性预测结果表明,预测的发震时间段长短大多数为２至６个月,可满足强震的中短期预报尺度的需要。     

走滑活动断裂带断错冲沟变形角特征及其构造意义初探

阐述了通过走滑活动断裂断错冲沟形成变形角研究冲沟形成年代,进而探讨断裂活动特征的方法。并以天桥沟－黄羊川断裂东段为例,对变形角大小和冲沟形成年代及冲沟水平断错距之间的关系进行了探讨,结果表明它们之间关系密切。最后论述了变形角用于走滑活动断裂研究的可能性及意义。     

Tree-Ring δD as an Indicator of Asian Monsoon Intensity

Oxygen and hydrogen isotopic compositions of meteoric water are known to correlate with surface air temperature, except in tropical areas. This relationship has been described using a number of terms corresponding to specific observations, such as latitude, altitude and seasonal effects. However, these temperature effects do not seem to apply to precipitation in monsoonal areas of Asia. Questions have been raised as to whether the isotopic composition of meteoric water can be used to reconstruct paleomonsoon intensity. Tree rings of two modern spruce trees (Picea meyeri) and a 10,000-yr-old timber (Picea jezoensis) were analyzed for hydrogen isotopic composition. On average, the older tree is depleted in deuterium by 45‰ compared to the modern trees. We attribute this isotopic depletion to the strength of summer monsoons, which were more intense in the early Holocene than at present. Although this study is not definitive, it suggests that paleomonsoon intensity can be reconstructed by direct or proxy methods that yield the oxygen or hydrogen isotopic composition of meteoric water.     

Integrating Stalagmite, Vertebrate, and Pollen Sequences to Investigate Holocene Vegetation and Climate Change in the Southern Midwestern United States

Speleothem carbon and oxygen isotopic records from Onondaga Cave, south-central Missouri, and Beckham Creek Cave, north-central Arkansas, are compared with the Cupola Pond and Oldfield Swamp pollen series from southeastern Missouri and the Rodgers Shelter and Modoc Shelter vertebrate biostratigraphic sequences from central Missouri and southwestern Illinois. Similar, and roughly contemporaneous, shifts between deciduous forest and steppe indicators throughout the Holocene are revealed in each database. These independent proxies record steppe conditions between approximately 9000 and 1500 cal yr B.P. A shift toward lighter speleothem carbon may reflect a change from warm and dry to cool and dry conditions between 4500 and 3000 yr B.P. The sensitive response of speleothem δ¹³C to changes in vegetation emphasizes their importance as paleoclimate records in an area containing few other millenial-scale climate proxies.     

Role of coal type and rank on methane sorption characteristics of Bowen Basin, Australia coals

The effect of coal composition, particularly the organic fraction, upon gas sorption has been investigated for Bowen Basin and Sydney Basin, Australia coals. Maceral composition influences on gas retention and release were investigated using isorank pairs of hand-picked bright and dull coal in the rank range of high volatile bituminous (0.78% R_{o max}) to anthracite (3.01% R_{o max}). Adsorption isotherm results of dry coals indicated that Langmuir volume (V_L) for bright and dull coal types followed discrete, second-order polynomial trends with increasing rank. Bright coals had a minimum V_L at 1.72% R_{o max} and dull coals had a minimum V_L at 1.17% R_{o max}. At low rank, V_L was greater in bright coal by about 10 cm³/g, but as rank increased, the bright and dull trends converged and crossed at 1.65% R_{o max}. At ranks higher than 1.65% R_{o max}, both bright and dull coals followed similar trends. These competing trends mean that the importance of maceral composition on V_L varies according to rank. In high volatile bituminous coals, increases in vitrinite content are associated with increases in adsorption capacity. At ranks higher than medium to low volatile bituminous, changes in maceral composition may exert relatively little influence on adsorption capacity. The Langmuir pressure (P_L) showed a strong relationship of decreasing P_L with increasing rank, which was not related to coal type. It is suggested that the observed trend is related to a decrease in the heterogeneity of the pore surfaces, and subsequent increased coverage by the adsorbate, as coal rank increases. Desorption rate studies on crushed samples show that dull coals desorb more rapidly than bright coals and that desorption rate is also a function of rank. Coals of lower rank have higher effective diffusivities. Mineral matter was found to have no influence on desorption rate of these finely crushed samples. The evolution of the coal pore structure with changing rank is implicated in diffusion rate differences.     

北海外沙泻湖全新世微体古生物群特征及其古地理意义

通过对北海外沙泻湖CK10 钻孔岩芯进行硅藻、有孔虫、孢粉的综合分析, 发现全新世地层中有8 个硅藻组合带,5 个孢粉组合带和5 个有孔虫组合。结合14C测年资料与沉积物特征, 认为该泻湖全新世地层可划分为早全新世、中全新世、晚全新世。植被演替为混有落叶阔叶林的亚热带常绿阔叶林→亚热带常绿林→亚热带、热带常绿阔叶林→混杂有中、北亚热带落叶阔叶林的南亚热带季风雨林→南亚热带常绿阔叶林。气候演变依次为热湿偏凉干→热湿→炎热潮湿→热湿偏凉→热湿。沉积相发展顺序为河漫滩相→河口沼泽相→河漫滩相→河口沼泽相→河口湾相→泻湖相→河口湾相→泻湖相。     

Holocene environmental change according to lake core in Fildes Peninsula of King George Island,Antarctica

Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Through measuring the organic carbon, magnetic susceptibility, granularity and organic carbon isotope of GA7, by use of 14C age it was estimated that there were four periods of high temperature in Fildes Peninsula; 4800-4400 aB. P. , 3600-3350 aB. P. ,2100 - 1800 aB. P. and 900 aB. P. - present. Meanwhile, results showed that there was a strikingly positive correlation between the content of organic carbon and that of organic carbon isotope (δC01213 ) which could be the substitute indicators of environmental temperature.