Timing and maximum flood level of the Early Holocene glacial lake Nedre Glomsjø outburst flood,Norway

This study discusses the timing and maximum flood level of the Nedre Glomsjø outburst flood, Norway, based on sediment records retrieved from 15 bog and lake basins located close to the purported maximum flooded level. The sediment records in 12 of the basins consist of a distinct light-coloured silty bed that is correlated to the outburst-flood-deposited ‘Romerike Silt Bed’ identified elsewhere in the region. The silt bed is recorded in basins up to a certain elevation and is absent above this level. The new maximum flood level inferred from the basin sediment records exceeds the established landform-induced palaeostage indicators by 5–10 m. The data indicate a higher maximum flood level and larger inundation area than previously suggested and highlight the importance of acquiring a wide range of geological data when reconstructing palaeofloods. Radiocarbon dates of terrestrial macrofossils found stratigraphically above and below the Romerike Silt Bed suggest that the glacial lake Nedre Glomsjø outburst flood occurred between 10.5 and 10.3 cal. ka BP. The new and well-constrained timing of the outburst flood is beneficial for reconstructing regional deglaciation and provides a precise age for the Romerike Silt Bed chronostratigraphical marker, which is of value for studies in SE Norway and adjacent regions.     

Hydrologic characteristics of floods in Ganges–Brahmaputra–Meghna (GBM) delta

In the middle of 2007, a severe flood affected the People’s Republic of Bangladesh. This is a natural disaster that takes people’s lives, destroys livestock, infrastructures and communication systems and, damages crops and fish ponds. Despite many adverse impacts, the flood situation is an accepted phenomenon to the citizens of Bangladesh, due to the immense increase of soil fertility due to the flood, plus, the recharge of aquifer, ecosystem and fish. The flood of 2007 was the 5th major flood of the last 20 years when more than thirty-five percent of the area of the country was inundated with flood water. As in the past, the flood of 2007 had its own significance. The geography of the country contains a floodplain delta of three major river basins: the Ganges, the Brahmaputra and the Meghna (GBM). The mean monthly rainfall plot from the TRMM satellite data has shown that for both the Meghna and Brahmaputra basins, the rainfall was higher during July 2007 than any other months of the last 2 years. This excess rainfall had accumulated in the Brahmaputra and Meghna rivers and carried downstream to Bangladesh. This was the main cause of the flooding in 2007. The first crossing above the danger level of the river waters was observed at Durgapur station of the Someswari and at Sunamganj station of the Surma on the nineteenth of July, 2007 inside Bangladesh. In terms of magnitude of the peak and duration of the flood, the Brahmaputra was higher in 2007 than during 2004. However, the Ganges river water level never crossed the danger level during flood of 2007. The Meghna was lower during the flood peak for the duration of the flood in 2007. The year–to-year variability in both the magnitude and duration of the flood suggests changes in rainfall and landuse pattern of the catchment.     

Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA

Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect glacial extent. The two areas are at similar latitudes and yield similar records of glacial growth and recession, even though UKL lies less than 200 km from the ocean and BL is in the continental interior. As sea level began to fall prior to the global Last Glacial Maximum (LGM), existing glaciers in the UKL area expanded. Near the beginning of the global LGM (26.5 ka), the BL record indicates onset of glaciation and UKL-area glaciers underwent further expansion. Both records indicate that local glaciers reached their maximum extents near the end of the global LGM, remained near their maxima for ~ 1000 yr, and underwent two stages of retreat separated by a short period of expansion.     

Vol.34 No.1( Sum136 )

Review on the development of studies on the tectonic and orogen process of　orogenic belt,and discussing on some new key problems 　　………………………　　　 ZH ANG Guo- wei,DONG Yun- peng,YAO An- ping(9)　…………………………A primary research on some major issues of desertification 　　………………………　　　 WANG Min,YUE L e- ping,LI Zhi- pei,NIE H ao- gang(1 7)　………………………On the put out fire in coal field burning regions of Xinjiang　　………………………　　　 ZH AN…     

Abstracts of Acta Geologica Sinica (ChineseEdition) Vol.78,No.6,2004

Discovery of Parachuaria from the Chuanlinggou Formation of the Changcheng System in the Yanshan Region and Its SignificanceSUN Shufen, ZHU Shixing, HUANG Xueguang, CAO Fang and XIN Houtian(Tianjin Institute of Geology and Mineral Resources, China Geological Survey, Tianjin 300170)     

Multiscale modelling of rainstorm-induced historical intermediate floods (June–November) in the Rhone River Basin

This study reveals the changes and evolution of rainstorm-driven intermediate floods occurring and driving multiple damaging hydrological events in the Rhone River Basin (RRB), since 1500 until 2010. A parsimonious approach was developed to simulate the major hydroclimatological flood-producing forcing, the Multiscale Rainstorm Climate Model (STORMCLIMM). We collected the frequency of intermediate floods—a type of particularly hazardous floods commonly taking place between June and beginning of November—from the RCB to be compared to STORMCLIMM estimates. The latter, smoothed by a moving window of 21 years, results in a high-pass filter in the time domain, which magnifies the signal of forcing variations causing intermediate floods. The RRB showed large temporal variations in both extreme rainstorms and associated multidecadal intermediate-floods (MUDIF) frequency at different climatic periods and land-use systems through historical times. An important peak was observed in the Maunder Minimum (1645–1715 AD). The model allowed detecting MUDIF occurred in the historical times. The situation becomes interesting with respect to recent times, because the Rhone landscape looks more vulnerable in the last decades as a consequence of land-use changes and climate shift towards more erratic and intensive storms. This evidence suggests that the interactions of land-use and climatic changes may turn into considerable vulnerability to fluvial flooding and agro-ecosystem connected to them for upcoming years. The Rhone, for example, provides basis for use of hydrological indicators (such as the one represented by STORMCLIMM) for one site or region and which, through minor modifications, can be made relevant to specific needs.     

AbstractsofActaGeologicaSinica(ChineseEdition) Vol.78,No.4,2004

A New Study on the Stratotype and Biostratigraphy of the Yixian Stage in the Yixian-Beipiao Region, Liaoning --Establishment and Study of the Yixian StratotypeWANG Wuli, ZHANG Lijun, ZHENG Shaolin, ZHENG Yuejuan, ZHANG Hong, LI Zhitong and YANG Fanglin (Shenyang Institute of Geology and Mineral Resources, Shenyang, Liaoning 110032)     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 79, No. 4,2005

On the Stratigraphic Sequence, Lithological Characteristics and Origin of the Lower Permian Pangduo Group in Lhunzhub County, TibetJI Zhansheng, YAO Jianxin, WU Guichun, ZHAN Lipei, JIANG Zhongti and FU Yuanhui(Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037; Geologica] Physical Data Center, Ministry of Land and Resources, P. R. China, Hebei 065201; China University of Geosciences, Beijing 100083)The paper deals with the sequence and lithologi…     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 78, No. 5,2004

Research on Conodont Biostratigraphy near the Bottom Boundary of the Middle Triassic Qingyan Stage in Southern Guizhou ProvinceYao Jianxin, Ji Zhansheng, Wang Liting , Wang Yanbin andWu Guichun(1. Institute of Geology, Chinese Academy of GeologicalSciences, Beijing, 100037; 2. Bureau of Geological and MineralResources Survey of Guizhou Province, Guiyang, Guizhou550004)     

Abstracts of Acta Geologica Simca(Chinese Edition) Vol.80,No.12,2006

Quantitative Determination of Chemical Compositions of Solid Exsolution Lamellae in Apatites from the Chinese Continental Drilling (CCSD) Project: An Application of Energy Dispersive Spectroscopy (EDS) with SEM CHEN Fangyuan, ZENG Lingsen and LIANG Fenghua (Key Laboratory for Continental Dynamics, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037) Solid exsolution lamellae of various sizes have been reported in rock-formimg process as well as acce…     

Abstracts of Acta Geologica Sinica (Chinese Edition)Vol. 79, No. 2,2005

The middle and late Permian faunas from the west Qinling Mountains have suffered a replacement event during the developing history. It behaves that the fusulinids occurring from the bottom of the late Maokouan Dieshan Formation of the middle Permian were sharply reduced or disappeared, and the brachiopods were prosperously developed. The fusulinids are well developed in the middle Maokouan Reranggou Formation,     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 79, No. 5,2005

Rheatian and Hettangian Ammonoid Assemblages from the Tibetan Himalayas and Their Pan-Tethyan Correlation YIN Jiarun(China University of Geosciences, Beijing 100083) On the basis of new collections from the Lanongla area, Nyalam County, Tibet, Rheatian and Hettangian ammonoid assemblages are recognized, including the Choristoceras marshi, Neophyllites-Choristoceras, Psiloceras calliphyllum and Discamphiceras pleuronotum assemblages. As the only Triassic and Jurassic boundary …     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 79, No. 6,2005

Morphologic Differentiation and Taxonomy of Anisograptus from the Lower OrdovicianLI Ming, FENG Hongzhen and LIU Bo(Department of Earth Sciences, Nanjing University, Nanjing, Jiangsu 210093; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing, Jiangsu 210008)Specimens from the Hule area of Ningguo County, Anhui Province and data of all 25 known species and subspecies shows that Anisograptus has apparent morphologic differentiation in the length of primary stripes, the…     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 76, No. 4,2002

This paper preliminary reports the carbon isotopic characteristicsof kerogen, individual hydrocarbons and associated carbonatepreserved in Paleo- to Neoproterozoic (1.9-0.85 Ga) sedimentsfrom Jixian strata section, North China. A comparison wascarried out between these isotopic data and independent     

Contents of Acta Geologica Sinica (Chinese Edition) Vol. 81,No. 3,2007

Planktonic Foraminiferal Zone，Climate，BioProductivity ExPlosion Event，and Time Limit Of Change in Subsiding Velocity in the South China Sea Basfon duringthe Neogene LIN Jin群ing，YANG Huining，J认NG Shijun，协俩NG ShaQfong，Z产IANG Jing，协五了Mingrui     

Abstracts of Acta Geologica Sinica (Chinese Edition)Vol. 78, No. 2,2004

Discovery of a Middle Jurassic Fossil Tadpole from the Ningcheng Region, Inner Mongolia, ChinaYUAN Chongxi, ZHANG Hongbin, LI Ming and JI Xinxin ( China University of Geosciences, Beijing 100083; China Dinosaur Park in Changzhou, Changzhou, Jiangsu 213022; Nanjing University, Nanjing, Jiangsu 210008)Mesozoic fossil amphibians are very rare in China, to name a few,     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 78, No. 3,2004

A Taxanomic Study on Primitive EuconodontsWU Guichun, YAO Jianxin and JI Zhansheng(Institute of Geology, Chinese Academy of Geological Sciences,Beijing 100037)Primitive euconodonts are extrmely abundant and varied in the Late Cambrian in western Shandong Province. Two new genera are established, including Camconodontus gen. nov. and Laiwunodus gen. nov. Among them the following species are described: Camconodontus rotundatus gen. et sp. nov., Camconodontus sp., Laiwunodus lateronodus gen. et sp. nov., and     

Abstracts of Acta Geologica Sinica (Chinese Edition) Vol. 78, No. 3,2004

A Taxanomic Study on Primitive EuconodontsWU Guichun, YAO Jianxin and JI Zhansheng(Institute of Geology, Chinese Academy of Geological Sciences,Beijing 100037)Primitive euconodonts are extrmely abundant and varied in the Late Cambrian in western Shandong Province. Two new genera are established, including Camconodontus gen. nov. and Laiwunodus gen. nov. Among them the following species are described: Camconodontus rotundatus gen. et sp. nov., Camconodontus sp., Laiwunodus lateronodus gen. et sp. nov., and