南极海冰变化异常与全球海平面变化(英)

In this paper, the long-term variation trend of the Antarctic sea ice in 1973～1994 and the inter-decade variation rule of the global sea level are analyzed. It is foundthat, the Antarctic sea ice area in 1980's was significantly less than in 1970's but with regional difference:decreasing in Regions Ⅰ, Ⅱ, and Ⅲ, and increasing in Region Ⅳ, the average global sea levelheightvalue in 1980's was also significantly higher than in 1970's but also with very large regional difference.Connecting variation of both to analyze their physical mechanism, it is pointed that, the accumulated seaice anomaly value in 1980's less than in 1970's means a global climate warming, the sea watertemperature and air temperature rising, sea water volume expanding, and more icebergs transportingfrom the ice cover on the Antarctic continent to ocean in the warmer years. As a result, the global sealevel raised significantly with the global average sea level value in 1980's was 22 mm higher than in 1970's. The Sea Level Raising (SLR) distributed uneven. It is especially true in the Pacific Ocean andAtlantic. This kind of uneven SLR distribution closely relates to, or is introduced by the uneven sea ice change of the Antarctic Regions.     

云南三江并流地区气候变化及其对生态环境的影响

利用EOF等方法通过计算1971-2000年30年来云南三江并流地区6个气象台站气温、降水、蒸发资料，分析了云南三江并流地区近30年来气候变化的异常特征及其对生态环境的影响，结果表明：云南三江并流地区气候变化表现为气温升高、降水略有减少和蒸发增大的干旱化气候变化趋势，同时，在气候干旱化和人为活动的影响下出现草场退化、冰川萎缩、雪线上升、土壤沙化和水土流失等生态环境荒漠化问题。     

渤海湾盆地早第三纪水平面升降和全球海平面升降的不一致性

本文通过对渤海湾盆地下第三系中半咸水化石纵向分布特点研究,并根据新的地层划分方案,利用古生物－岩相综合分析方法绘制了该地区早第三纪水平面升降曲线,发现半咸水生物出现在水进初期,在最大水进期消失,水平面升降曲线一全球海平面升降曲线无直接关系,即水平面的上升示受海平面上升的影响,从而证明此阶段无海侵发生,非海侵观点对于总结我国陆相地层的油气勘探理论及实践具有重要意义。     

Ice-core records of global climate and environment changes

Precipitation accumulating on the Greenland and Antarctic ice sheets records several key parameters (temperature, accumulation, composition of atmospheric gases and aerosols) of primary interest for documenting the past global environment over recent climatic cycles and the chemistry of the preindustrial atmosphere. Several deep ice cores from Antarctica and Greenland have been studied over the last fifteen years. In both hemispheres, temperature records (based on stable isotope measurements in water) show the succession of glacial and interglacial periods. However, detailed features of the climatic stages are not identical in Antarctica and in Greenland. A tight link between global climate and greenhouse gas concentrations was discovered, CO₂ and CH₄ concentrations being lower in glacial conditions by about 80 and 0.3 ppmv, respectively, with respect to their pre-industrial levels of 280 and 0.65 ppmv. Coldest stages are also characterized by higher sea-salt and crustal aerosol concentrations. In Greenland, contrary to Antarctica, ice-age ice is alkaline. Gas-derived aerosol (in particular, sulfate) concentrations are generally higher for glacial periods, but not similar in both the hemispheres. Marine and continental biomass-related species are significant in Antarctica and Greenland ice, respectively. Finally, the growing impact of anthropogenic activities on the atmospheric composition is well recorded in both polar regions for long-lived compounds (in particular greenhouse gases), but mostly in Greenland for short-lived pollutants.     

The Loess in the Qinling Mountains and Its Records of Palaeoenvironmental Changes

The Fengzhou loess section is very typical in the Qinling Mountains. The section, which is about 82 m thick and underlain by Neogene red clays, consists of 33 layers of loess and 33 layers of palaeosol. It covers the Brunhes normal polarity zone and Matuyama reversed polarity zone, and the B/ M boundary is located in the middle part of loess layer 8 (L8). The loess of the Matuyama reversed polarity zone records the Jaramillo, Olduvai and Reunion normal polarity subchrons. The boundary between the Matuyama reversed polarity zone and Gauss normal polarity zone (M / Ga) appears on the lithological boundary between loess and Neogene red clays. Loess accumulation in the Fengzhou section started before 2.48 Ma B.P. Based on the stratigraphical structure, the material composition and magnetic susceptibility curve of the Fengzhou loess section, the palaeoclimatic changes during the last 2.48 Ma in the Qinling Mountains are subdivided into 66 cold-dry and warm-humid stages, equivalent to 33 climatic cycles. The     

巴州坳陷下白垩统—中侏罗统的粘土矿物特征

根据岩石薄片、Ｘ衍射和扫描电镜分析资料,本文研究了巴州坳陷下白垩统—中侏罗统粘土矿物特征,发现粘土矿物分为伊利石、伊／蒙混层和绿泥石三种类型。粘土矿物的类型和含量随深度而变化,形成了伊／蒙混层带、混层迅速转化带和伊利石带。粘土矿物的转化和自生粘土矿物的形成是沉积地层非常重要的成岩变化。     

东海陆架全新统高分辨率层序地层学研究

在高分辨率１４Ｃ测年、岩石、生物、化学、同位素、气候及磁性地层学研究成果基础上,通过不同沉积背景典型钻孔的沉积学分析,运用层序地层学理论,对东海陆架全新统进行了高分辨率层序划分及对比;建立了全新世层序地层格架及海平面变化过程;提出了相应的层序成因模式。研究结果表明,东海陆架全新统相当于一个发育中的六级（１～１０ｋａ）层序,可进一步划分为３个七级（０．１～１ｋａ）层序和若干个更次级层序。代表１个六级或３个七级周期相对海平面变化过程中叠加有若干更次级的海平面波动,它们与地球旋回谱系中的太阳带、历法带密切相关。七级层序具有与三级层序相近的内部构型和成因格架。在东海陆架全新世沉积演化过程中,长江三角州至少有３次不同程度地越过东海陆架进入冲绳海槽,并滞留有至少３层海侵改造“残积砂”沉积。在东海陆架全新世海平面变化期间,最大海平面时期为约距今６～５ｋａ,大致高于现今海平面２～４ｍ,最低海平面在距今１０ｋａ左右,大约低于现今海平面１３０ｍ。目前,由于温室效应的影响,海平面仍呈小幅度波浪式上升。事实证明,层序地层学不仅丰富了现代海洋沉积学的内容,而且解决了许多海洋沉积学未能解决的问题。     

基准面变化与层序地层——以塔里木盆地陆相地层为例

以海平面变化 为基出的层序地层学理论在研制陆相盆地中遇到了困难,地层基准面变化 在解释地层层序成因和地层层序发挥了重要作用。     

塔里木盆地三大遗址群的兴衰与环境变化

塔里木盆地中的三大遗址群都经历了公元前的兴起、1～3世纪的兴盛和发展,以及7世纪的废弃。它们的兴衰变化具有一定的同步性。这意味着导致水资源条件变化的原因是共同的,即气候变化,而不是人为因素。