青藏高原地质科学研究的新进展

《青藏高原隆升的地质记录及机制》科研项目实施4年取得一些新进展:证实西昆仑存在两种基底和4期构造变形;大幅度提高了可可西里盆地研究程度,重塑了滇西高原隆升史;厘定了冈底斯构造-岩浆岩带时空结构和地壳生长方式;进一步查明羌塘地区新生代火山岩存在3个亚带和4个活动高峰期;确定南迦巴瓦构造结为一楔入构造,由3个构造单元组成,南迦巴瓦群为元古宇;GPS监测获得高原北部地壳运动速率,发现两个涡旋构造;把高原岩石圈划分为3种类型,识别出3种地球化学端元;获得一批有关高原隆升、盆地沉积、地质年代等的新数据,对高原隆升及对气候影响等提出一些新认识。     

Problems of riverbed evolution in the basin of the Ural River

Aspects of riverbed evolution including bank erosion in the Ural River basin have been considered in this paper. The natural morphodynamic types of riverbeds have been described. The spatial features of their genesis have been characterized within the Ural River basin. To study the riverbed processes, decoding of remote sensing data of the water surface has been used. The risks for the infrastructure facilities and for the residential districts have been analyzed in terms of the bank erosion in the Ural River basin. The issues concerning the border between the Russian Federation and the Republic of Kazakhstan due to riverbed reconfiguration of the Ural River have been outlined. Maps of the development of bank erosion in the Ural River basin have been created. A way to solve the problem of riverbed evolution along the border area has been proposed by organizing an Intergovernmental Specially Protected Natural Zone.

     

A characterization and the formation conditions of the Callovian-Upper Jurassic deposits in the Akhtsu zone (Krasnodar Krai)

Deposits in the Akhtsu zone have been characterized, with the Mzymta River valley as an example. A lithological-paleontological and geochemical characterization of Callovian-Tithonian deposits has been given. A paleogeographic model has been proposed for the Akhtsu reef, and a chronostratigraphic profile has been established for the Callovian-Albian sedimentary basin in the Easter Black Sea region.     

ESR dating and the human evolution: contribution to the chronology of the earliest humans in Europe

In the last 20 years, the electron spin resonance (ESR) dating method has allowed the establishment of a chronological time frame over most of the history of human evolution. Despite many difficulties found for ESR dating of bones and carbonates, tooth enamel dated by ESR has been proven as a reliable method in its application to fossil teeth and quartz. Both of the latter materials have allowed dating of Early and Middle Pleistocene sites which are not datable using other methods such as the Argon–Argon method. In particular, recent discoveries of human remains in western Europe have been proposed to be sites of the earliest arrival of humans there, and have been dated to the Early Pleistocene by ESR using quartz and tooth enamel.Combined ESR and U-series dating of fossil herbivore teeth are the only means of dating layers from which such ancient remains have been recovered in western Europe. Good examples are the sites of Atapuerca Gran Dolina, Spain and Visogliano, Italy which have been dated using tooth enamel.When no bones and teeth can be found in prehistoric sites, ESR dating on quartz extracted from sediments has been used to date sites whose ages range over the entire Quaternary period. We present here two examples that occur in fluvial terraces of the river Creuse, France and at Monte Poggiolo site, Italy, where several artefacts of an archaic pebble industry have been recovered.     

青藏铁路沿线融区的特征及其变化趋势

基于青藏铁路多年冻土区工程长期监测系统所获取的地温与变形资料,对铁路沿线4处融区的特征及其变化趋势进行了分析。这4处融区分别为沱沱河北面洼地辐射-渗透融区（R1）、休冬曲北岸河流融区（R2）、扎加藏布河西岸河流融区（R3）与洼里希里唐盆辐射-渗透融区（R4）。结果表明：R1土体温度处于升温中,融区正在发展;R2土体温度较为稳定,位于融区边缘地带;R3土体升温趋势明显,融区处于快速发展之中;R4深部土体温度较为稳定,融区仍处于稳定状态。在R1、R3与R4,路基下未形成隔年冻土;但在R2融区,路基下有形成隔年冻土的可能。监测期内,路基累计沉降变形小于50 mm,满足铁路路基设计规范的要求。     

21世纪初10年火山与地球内部化学研究进展

进入21世纪,我国除了在长白山天池火山、五大连池火山和腾冲火山三个主要活动火山区进行监测与研究,还开展了中国其他第四纪火山区的活动火山调查工作,发现并确定了一些新的活动火山,如镜泊湖、大兴安岭、乌兰哈达等第四纪火山区中存在的全新世火山.自峨眉山大火成岩省被确定以来,我国近10年在大火成岩省研究方面取得了重要进展,并新确定了一些新的大火成岩省,如塔里木大火成岩省和措美大火成岩省,逐渐为国际地学界所接受.     

On the problem of water diffusion in the cordierites

The dehydration of cordierites in vacuo has been studied by mass spectrometry. Activation energies of dehydration from cordierites of epidote-amphibolitic, amphibolitic and two-pyroxenitic facies have been established to be 25–40, 30–50 and 50–65 kcal/mol, respectively. The conclusion drawn, based on these values, is that natural cordierites with higher H_aO were cooled at depth, or that they have been formed not by metamorphic processes of normal subsidence but by additional thermal sources.     

雅鲁藏布江缝合带开合演化模式的探讨

通过对雅鲁藏布江缝合带的蛇绿岩、构造混杂岩的地质调查及其岩石化学、地球化学特征的分析,进一步证实了雅鲁藏布江缝合带萨嘎分岔的存在,探讨了雅鲁藏布江缝合带的演化模式。将雅鲁藏布江缝合带分为南、北两带,南带起始于二叠纪末期印度板块向北漂移过程中的伸展作用,到三叠纪末-早侏罗世,雅鲁藏布江缝合带南带伸展作用加剧,并伴有洋壳的裂陷和蛇绿岩的侵位,在较短暂的双向俯冲、碰撞后焊接了仲巴陆块。晚侏罗世到早白垩世之后,雅鲁藏布江缝合带北带再次扩张、俯冲,直到始新世晚期整个缝合带开始剧烈碰撞、造山、隆起,形成了雄伟的青藏高原。     

Sources of the RCR catalog with normal and flat spectra according to data from the Planck microwave survey

Fields of the Planck cosmic-microwave background maps in the regions of radio sources of the RCR catalog have been studied. Using measurements from the Planck catalog, calibration curves have been plotted in order to determine the objects’ luminosities. The flux densities at millimeter and submillimeter wavelengths of 83 objects with normal radio spectra have been estimated for the first time; their spectra have also been constructed, they have been optically identified, and information available in various databases has been collected. A statistical comparison with a sample of sources with steep radio spectra has been carried out. Faint, difficult to characterize microwave sources make an additional contribution to the secondary anisotropy on angular scales < 7′. An algorithm for selecting candidate objects with the Sunyaev–Zel’dovich effect has been proposed, based on the use of data on the radio spectral indices and the signal in cosmic-microwave background maps.     

Acritarchs from the Lower Palaeozoic succession on the south County Wexford coast,Ireland: new age constraints for the Cullenstown Formation and the Cahore and Ribband Groups

Lower Palaeozoic sediments crop out on the southern coast of County Wexford, Ireland, comprising three distinctive lithostratigraphical units: from west to east the Cahore Group, the Blackhall Formation of the Ribband Group and the Cullenstown Formation. The three units are largely devoid of macrofossils and thus their ages have to date been uncertain and, in the case of the Cullenstown Formation, speculative. In the Cahore Group, a diverse assemblage of acritarchs composed of seventeen species has been recorded indicating a middle Early Cambrian age. This is similar to the age of the lithologically identical Bray Group to the north, in County Wicklow. In the Ribband Group, two very distinct assemblages have been noted. Both are poorly preserved, but diagnostic species have been determined giving a biostratigrapical range of early Mid‐Cambrian to Llanvirn. Palynomorphs have been recorded for the first time from the Cullenstown Formation allowing comparison with eastern Newfoundland where a similar, less diverse assemblage has been recorded. The age indicated is latest Mid‐Cambrian to early Late Cambrian. Overall, despite generally poor preservation of the organic matter, some 45 acritarch species have been distinguished, among which one new combination is proposed: Retisphaeridium postae instead of Cymatiosphaera postae. Copyright © 2004 John Wiley & Sons, Ltd.     

Changes in the mass balance of the Antarctic Ice Sheet over 50 years

The mass balance of the Antarctic Ice Sheet has been calculated based on instrumental estimates of the grounded ice discharge and snow accumulation data. The boundaries and sectional areas of the main ice catchment basins in West and East Antarctica have been determined, and the data on the grounded ice discharge and snow accumulation in these basins have been systematized. The intensity of accumulation and ablation processes in Antarctica has noticeably increased over the last 50 years. The mass balance of the ice sheet in East Antarctica has been and remains positive, while in West Antarctica it was positive in the middle of the last century and has become negative by now. The mass balance of the entire Antarctic Ice Sheet has been and remains positive, while the mass growth has noticeably decreased over the last 50 years.     

青阳水库坝基帷幕灌浆防渗工程施工方法

介绍了青阳水库坝基基岩帷幕灌浆防渗工程的施工工艺以及在钻孔和灌浆施工过程中,针对特殊情况所采取的技术措施。     

Kinematic History and Changes in the Tectonic StressRegime during the Cenozoic along the Qinling andSouthern Tanlu Fault Zones

Since the mid-late Eocene, North China has been subjected to extensional stress, resulting in the formation and development of basins. The dynamic origin of this crustal extension has long been an issue of debate. This paper presents the results of kinematic analyses of faults obtained from two seperated areas in North China. In the Weihe graben situated on the southernmost margin of the Ordos block, analyses of fault kinematics were coupled with an analysis of the basin's subsidence history. Three successive extensional tectonic phases accompaning the basin's formation and development have been distinguished. The Palaeogene extension was oriented in a WNW-ESE direction; the Neogene extension in a NE-SW direction and the Pliocene-Quaternary extension in a NW-SE direction. Such changes have also been recorded by fault kinematics along the southern Tanlu fault zone. This has been demonstrated by three successive sets of fault striations indicating normal dip slip resulting from NW-SE extension, then left-     

试刀山隧道岩溶破碎体的成因分析及处理措施

本文从气象，构造，水文地质条件，工程地质条件等方面综合分析了试刀山隧道特大“岩溶破碎体”复杂的地质成因，并总结了经过施工，运营考验的成功的“管梁”处理措施方案，希望能为类似工程地质条件下工程的处理提供有益的借鉴。     

Influence of the Sedimentary Cover in the Cologne Area on the Shape of Response Spectra

For the greater area of the city of Cologne a microzonation from an earthquake engineering perspective was introduced. The area has been divided into eight subregions with approximately uniform soil profile. For all regions the influence of the sediments on simulated earthquakes has been investigated by three well known methods: 2-layer solution, SHAKE 91, HASKELL matrix algorithm. The transfer functions and response spectra were computed and compared to the elastic acceleration response spectra of the German building code E-DIN 4149. Two different methods for the generation of synthetic accelerograms and the three wave propagation analysis procedures have been compared and a series of issues relevant to the practical application of them were discussed.     

Self-purification in the context of the problems of anthropogenic ecology of the sea

Some laws governing the self-purification of marine waters from oil products have been considered using the Sea of Azov and the NW shelf of the Black Sea as models. A number of principally important features of this process have been established including marked spatial heterogenity, and capacity for a sharp decline in the efficiency of destruction during anthropogenic transformations of marine ecosystems, etc. On the basis of a special mathematical model and numerous experiments, an estimation in the first approximation was made of the efficiency of the self-purification of the areas investigated and their characteristic regions. The value obtained is significantly smaller than the actual amount of oil products entering the sea as runoff. A number of recommendations have been made on the use of self-purification values for establishing standards for discharges of waste waters.     

Neotectonics of the Manych Trough

The general (regional) and local neotectonic features of the Manych Trough have been discussed. It has been shown that the trough’s bottom was generally immersed at a slow but stable rate of 0.1 mm/year with an amplitude of 40–50 m. Additionally, migration of portions of the maximal and minimal immersion has been identified. All the local tectonic rises in the Manych Trough were thresholds during the existence of the strait in the past and various evidence for their neotectonic activity, with the maximums in Early and Late Khazarian epochs, has been found.     

SPOT卫星影像在德尔尼铜矿区域地质研究中的应用

利用卫星遥感影像对青海省德尔尼铜矿区的区域地质做了判释性研究 :( 1)判释出 3条左旋平移断层及一组羽式构造 ,并测得其中一条断层的左旋平移距离为 12 50m ,而在以往 1∶2 0万和 1∶5万的地质填图中均未发现这 3条断层的平移性质 ;( 2 )判释出作为蛇绿岩组成部分的地幔橄榄岩呈现与一般岩浆岩不同的影像特征。     

A first insight into the constitution of the upper mantle under the hoggar area (Southern Algeria): The lherzolite xenoliths in the alkali-basalts

Quaternary alkali olivine basalts and nephelinites from the Hoggar area (Southern Algeria) contain numerous lherzolite inclusions. The investigated nodules have been classified into three textural categories: coarse, porphyroclastic and granuloblastic. Microprobe analyses have been carried out on the coexisting phases (olivine, clinopyroxene, orthopyroxene, spinel, pargasite, Al rich glass) from 10 selected samples, with a special attention to pyroxene porphyroclasts which are zoned in Al and Cr. Most of the porphyroclastic xenoliths contain secondary pargasite (or its breakdown products) which is thought to reflect a metasomatic event in mantle conditions. Equilibrium temperatures and pressures have been calculated for the three groups, using the single-pyroxene method: the coarse samples have been equilibrated at higher pressures (20–25 kb) and temperatures (1,000° C–1,100° C) than the granuloblastic samples (about 10 kb and 900° C); with regards to the porphyroclastic xenoliths, the estimated T and P have been related to two stages of crystallization (corresponding to porphyroclasts and neoblasts). Relationships between phase compositions, rock-textures and metasomatism are briefly discussed.     

A contribution to the migration of gold in the biosphere of the humid mild zone

The content of gold in plants has been used as an indicator in the prospecting for gold. For this purpose non-destructive analytical methods have been developed. In the humid mild zone — where the process of weathering is of a kaolinitic character — there is practically no migration of gold, and consequently its increased content indicates the presence of a gold deposit.