bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconstruction of Ore‐controlling Structures Resulting from Magmatic Intrusion into the Tongling Ore Cluster Area during the Yanshanian Epoch
Authors: Jun DENG , Qingfei WANG , Liqiang YANG , Bangfei GAO , Dinghua HUANG , Yan LIU , Hao XU , Shaoqing JIANG
Published: February 2011

Abstract:The Tongling ore cluster area experienced intensive compression and associated shearing during the Indosinian‐Yanshanian Epoch, which formed a trunk ore‐controlling fold and fault system in the caprock. The magmatic intrusion in the Yanshanian Epoch induced a multi‐stage unmixing of poly‐phase fluids, resulting in mineralization characterized by multi‐layer, wide‐range, and multiform styles. The magmatic intrusion in the Tongling area not only supplied the essential ore‐forming materials, but also reconstructed the ore‐controlling structures according to a trend surface simulation of the following five strata boundaries: Silurian‐Devonian, Devonian‐Carboniferous, Carboniferous‐Permian, Middle Permian‐Upper Permian and Permian ‐Triassic. The result of this simulation shows that there exists a significant difference between the strata in the upper part and those in the lower. The lower trend surfaces are antiform whereas the upper trend surfaces are synform. In addition, superposing of the trend surfaces of adjacent bed boundaries (such as, Silurian‐Devonian boundary superposed upon Devonian‐Carboniferous boundary) shows that the lower trend surface always pierces the one above. Moreover, the position and orientation of the pierced parts of the different superposed trend surfaces are similar and show E‐W‐trending zonal distribution in accordance with the distribution of the regional E‐W‐trending magmatic‐metallogenic belt. Based on comprehensive analysis of the mechanical properties of the strata, structural deformation mechanisms, and field phenomena, it seems that the special characteristics of the stratal trend surface resulted from jacking due to magmatic intrusion into the caprock previously controlled by an E‐W‐trending basement fault. Therefore, it is deduced that the major ore‐controlling structures, which formed during regional horizontal compression, were reconstructed by the vertical jacking function of ore‐forming magmas during the Yanshanian Epoch. During the ore‐forming process, the local vertical jacking of magmas, coupled with the regional horizontal compression, optimized an extensive environment in the fluid‐conduit network and accelerated the unmixing of poly‐phase fluids following magmatic emplacement. Jacking also strengthened the vertical and lateral fluid‐guiding structures, supplying more suitable physical conditions for multi‐layer emplacement and wide‐ranging transport of poly‐phase fluids.
Precious Fossil‐Bearing Beds of the Lower Cretaceous Jiufotang Formation in Western Liaoning Province, China
Authors: Lijun ZHANG , Yajun YANG , Lidong ZHANG , Shengzhe GUO , Wuli WANG , Shaolin ZHENG
Published: February 2011

Abstract: Based on the subdivision into three members of the Lower Cretaceous Jiufotang Formation in western Liaoning, this paper deals mainly with the division and correlation of precious fossil bird‐and reptile‐bearing beds of the formation in the Dachengzi, Chaoyang, Dapingfang‐Meileyingzi and Fuxin‐Yixian basins. Among them, the precious fossil‐bearing beds in the Dachengzi Basin may be recognized as the Xidagou Bed of the second member and the Yangcaogoudonggou Bed of the third member; those in the Chaoyang Basin may be confirmed as the Shangheshou Bed of the second member and the Dongpochi Bed of the third member; those in the Dapingfang‐Meileyingzi Basin are as the Lamagou Bed of the second member, the Huanghuagou Bed of the lower third member and the Yuanjiawa Bed of the upper third member; and those in the Fuxin‐Yixian Basin are listed as the Tuanshanzi Bed of the second member and the Pijiagou Bed of the third member. Since these basins are distinctly separated and the bird and reptile fossils are mostly new genera and species, we have to use the associated fossil ostracod assemblages as index to correlate the Xidagou Bed with the Shangheshou Bed and the Lamagou Bed, and to correlate the Yuanjiawa Bed with the Yangcaogoudonggou Bed and the Pijiagou Bed. Primarily, we established the sequence of the precious fossil‐bearing beds of the Jiufotang Formation in western Liaoning. They are represented by, in ascending order, the Xidagou Bed of the second member, the Huanghuagou Bed of the lower third member, and the Yuanjiawa Bed of the upper third member. Obviously, this work has significance for the study on the time‐space distribution and radiation of birds and dinosaurs during the period of the middle Early Cretaceous.
Miocene Tectonic Evolution from Dextral‐Slip Thrusting to Extension in the Nyainqĉntanglha Region of the Tibetan Plateau
Authors: Zhenhan WU , BAROSH Patrick J. , Xun ZHAO , Zhonghai WU , Daogong HU , Qisheng LIU
Published: February 2011

Abstract: Dextral‐slip in the Nyainqĉntanglha region of Tibet resulted in oblique underthrusting and granite generation in the Early to Middle Miocene, but by the end of the epoch uplift and extensional faulting dominated. The east‐west dextral‐slip Gangdise fault system merges eastward into the northeast‐trending, southeast‐dipping Nyainqĉntanglha thrust system that swings eastward farther north into the dextral‐slip North Damxung shear zone and Jiali faults. These faults were took shape by the Early Miocene, and the large Nyainqĉntanglha granitic batholith formed along the thrust system in 18.3–11.0 Ma as the western block drove under the eastern one. The dextral‐slip movement ended at ∼11 Ma and the batholith rose, as marked by gravitational shearing at 8.6–8.3 Ma, and a new fault system developed. Northwest‐trending dextral‐slip faults formed to the northwest of the raisen batholith, whereas the northeast‐trending South Damxung thrust faults with some sinistral‐slip formed to the southeast. The latter are replaced farther to the east by the west‐northwest‐trending Lhünzhub thrust faults with dextral‐slip. This relatively local uplift that left adjacent Eocene and Miocene deposits preserved was followed by a regional uplift and the initiation of a system of generally north‐south grabens in the Late Miocene at ∼6.5 Ma. The regional uplift of the southern Tibetan Plateau thus appears to have occurred between 8.3 Ma and 6.5 Ma. The Gulu, Damxung‐Yangbajain and Angan graben systems that pass east of the Nyainqĉntanglha Mountains are locally controlled by the earlier northeast‐trending faults. These grabens dominate the subsequent tectonic movement and are still very active as northwest‐trending dextral‐slip faults northwest of the mountains. The Miocene is a time of great tectonic change that ushered in the modern tectonic regime.
Diagenesis and Fluid Flow History in Sandstones of the Upper Permian Black Jack Formation, Gunnedah Basin, Eastern Australia
Authors: Guoping BAI , KEENE John B.
Published: February 2011

Abstract: The fluid flow history during diagenesis of sandstones in the Upper Permian Black Jack Formation of the Gunnedah Basin has been investigated through integrated petrographic observations, fluid inclusion investigations and stable isotope analyses. The early precipitation of mixed‐layer illite/smectite, siderite, calcite, ankerite and kaolin proceeded at the presence of Late Permian connate meteoric waters at temperatures of up to 60°C. These evolved connate pore waters were also parental to quartz, which formed at temperatures of up to 87°C. The phase of maximum burial was characterized by development of filamentous illite and late calcite at temperatures of up to −90°C. Subsequent uplifting and cooling led to deep meteoric influx from surface, which in turn resulted in dissolution of labile grains and carbonate cements, and formation of second generation of kaolin. Dawsonite was the last diagenetic mineral precipitated and its formation is genetically related to deep‐seated mamagtic sourced CO2.
Burial Records of Reactive Iron in Cretaceous Black Shales and Oceanic Red Beds from Southern Tibet
Authors: Yongjian HUANG , Chengshan WANG , Xiumian HU , Xi CHEN
Published: February 2011

Abstract: One of the new directions in the field of Cretaceous research is to elucidate the mechanism of the sedimentary transition from the Cretaceous black shales to oceanic red beds. A chemical sequential extraction method was applied to these two types of rocks from southern Tibet to investigate the burial records of reactive iron. Results indicate that carbonate‐associated iron and pyrite are relatively enriched in the black shales, but depleted or absent in red beds. The main feature of the reactive iron in the red beds is relative enrichment of iron oxides (largely hematite), which occurred during syn‐depostion or early diagenesis. The ratio between iron oxides and the total iron indicates an oxygen‐enriched environment for red bed deposition. A comparison between the reactive iron burial records and proxies of paleo‐productivity suggests that paleo‐productivity decreases when the ratio between iron oxides and the total iron increases in the red beds. This phenomenon could imply that the relationship between marine redox and productivity might be one of the reasons for the sedimentary transition from Cretaceous black shale to oceanic red bed deposition.
Genetic Relationship between Natural Gas Dispersal Zone and Uranium Accumulation in the Northern Ordos Basin, China
Authors: Huajun GAN , Xianming XIAO , Yongchao LU , Yongbin JIN , Hui TIAN , Dehan LIU
Published: February 2011

Abstract: The Ordos Basin is well‐known for the coexistence of oil, natural gas, coal and uranium. However, there has been little research to discuss the genetic relationship between them. In this paper, a case study of the Zaohuohao area in Dongsheng, Inner Mongolia, China, is conducted to investigate the genetic relationship between the natural gas and the uranium accumulation. Fluid inclusion data from the uranium‐bearing sandstone samples indicate that the fluid inclusions formed in a gas‐water transition zone. Using the homogeneous temperatures of aqueous inclusions coeval with hydrocarbon‐bearing inclusions, combined with the buried history and paleo‐temperature data, the gas‐water transition zone reached the area at about 110 Ma. On the basis of this, the contents of Uranium (U) and Total Organic Carbon (TOC) of the samples were analyzed, and there was no obvious relation between them. With regard to the available data from both publications and this study, it is found that the U mineralization has a spatiotemporal accordance with the gas‐water dispersal zone. Thus, it is believed that the natural gas in the gas‐water zone is an effective reducer to the U‐bearing ground water abundant in oxygen, which is the main factor to U accumulation. This result can be used as the reference to the U mines predicting and prospecting.
Phases of Environmental Evolution Indicated by Primary Chemical Elements and Paleontological Records in the Upper Pleistocene‐Holocene Series for the Salawusu River Valley, China
Authors: Baosheng LI , Xiaohao WEN , Shifan QIU , ZHANG David Dian , Shuhuan DU , Deniu CHEN , Xianjiao OU , Dongfeng NIU
Published: February 2011

Abstract: Studies of lithology, sedimentary facies and the distribution regularity of SiO2 and Al2O3 contents and Al2O3/SiO2 ratio allow us to divide the Upper Pleistocene‐Holocene Series represented by the Milanggouwan section in China's Salawusu River valley into six segments: MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6. The boundary ages for MGS1 (the Dishaogouwan and Dagouwan Formations), MGS2 (the upper Chengchuan Formation), MGS3 (the middle Chengchuan Formation), MGS4 (the lower Chengchuan Formation), MGS5 (most strata of the Salawusu Formation) and MGS6 (the bottom of the Salawusu Formation and the top of the Lishi Formation) correspond to those of MIS1, MIS2, MIS3, MIS4, MIS5 and MIS6, respectively, from deep sea sediments or continental glaciers. MGS5 can be subdivided into five subsegments (MGS5a, MGS5b, MGS5c, MGS5d and MGS5e) and the boundary ages of these subsegments correspond to those of MIS5a, MIS5b, MIS5c, MIS5d and MIS5e, respectively. Based on the paleoenvironment and paleoecology indicated by the primary chemical elements, fossil vertebrates, mollusks and pollen grains, we hypothesize that MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6 and the subsegments of MGS5 match the corresponding stages for oxygen isotopes in the deep sea sediments and continental glaciers, and the substages of MIS5 in terms of climatic characters, further explaining the phenomena that determined the formation of the late Quaternary strata and the paleontology of the Salawusu River valley. These phenomena relate to fluctuations in the global climate (and particularly in the East Asian monsoon) during the glacial and interglacial periods.
Paleoecology of Late Carboniferous Phylloid Algae in Southern Guizhou, SW China
Authors: Enpu GONG , Yongli ZHANG , Changqing GUAN , SAMANKASSOU Elias , Baoliang SUN
Published: February 2011

Abstract: Phylloid algae are important reef‐builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well‐exposed reefs in Ziyun County, Guizhou Province. Phylloid algae growing closely packed are attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup‐shaped, cabbage‐shaped and clustering cup‐shaped. The thalli are of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine organisms are relatively scarce. Obviously, phylloid algae are stronger competitors for living space than other co‐occurring organisms.
Mesozoic‐Cenozoic Basin Features and Evolution of Southeast China
Authors: Liangshu SHU , Xinmin ZHOU , Ping DENG , Wenbin ZHU
Published: February 2011

Abstract: The Late Triassic to Paleogene (T3‐E) basin occupies an area of 143100 km2, being the sixth area of the whole of SE China; the total area of synchronous granitoid is about 127300 km2; it provides a key for understanding the tectonic evolution of South China. From a new 1:1500000 geological map of the Mesozoic‐Cenozoic basins of SE China, combined with analysis of geometrical and petrological features, some new insights of basin tectonics are obtained. Advances include petrotectonic assemblages, basin classification of geodynamics, geometric features, relations of basin and range. According to basin‐forming geodynamical mechanisms, the Mesozoic‐Cenozoic basin of SE China can be divided into three types, namely: 1) para‐foreland basin formed from Late Triassic to Early Jurassic (T3‐J1) under compressional conditions; 2) rift basins formed during the Middle Jurassic (J2) under a strongly extensional setting; and 3) a faulted depression formed during Early Cretaceous to Paleogene (K1‐E) under back‐arc extension action. From the rock assemblages of the basin, the faulted depression can be subdivided into a volcanic‐sedimentary type formed mainly during the Early Cretaceous (K1) and a red‐bed type formed from Late Cretaceous to Paleogene (K2‐E). Statistical data suggest that the area of all para‐foreland basins (T3‐J1) is 15120 km2, one of rift basins (J2) occupies 4640 km2, and all faulted depressions equal to 124330 km2 including the K2‐E red‐bed basins of 37850 km2. The Early Mesozoic (T3‐J1) basin and granite were mostly co‐generated under a post‐collision compression background, while the basins from Middle Jurassic to Paleogene (J2‐E) were mainly constrained by regional extensional tectonics. Three geological and geographical zones were surveyed, namely: 1) the Wuyishan separating zone of paleogeography and climate from Middle Jurassic to Tertiary; 2) the Middle Jurassic rift zone; and 3) the Ganjiang separating zone of Late Mesozoic volcanism. Three types of basin‐granite relationships have been identified, including compressional (a few), strike‐slip (a few), and extensional (common). A three‐stage geodynamical evolution of the SE‐China basin is mooted: an Early Mesozoic basin‐granite framework; a transitional Middle Jurassic tectonic regime; intracontinental extension and red‐bed faulted depressions since the Late Cretaceous.
First Record of Fossil Mesocupes from China (Coleoptera: Archostemata: Cupedidae)
Authors: Jingjing TAN , Diying HUANG , Dong REN
Published: February 2011

Abstract: Three new fossil species of the genus Mesocupes of fossil cupedids, M. angustilabialis sp. nov., M. latilabialis sp. nov. and M. collaris sp. nov., are described from the Jiulongshan Formation of Inner Mongolia, China. These new species are the first three records of fossil Mesocupes in China as well as the oldest ones in the world now. This finding also extends the geographical distribution of this genus from Central to East Asia. In addition, based on the ratio of the length of the last to the penultimate abdominal ventrites of new beetles distinctly lower than that of the species from the Karabastau Formation, the age of Daohugou fossil‐bearing beds might be older than that of Karatau assemblage and consequently of Middle Jurassic.
The Tunggurian Stage of the Continental Miocene in China
Authors: Tao DENG , Sukuan HOU , Hongjiang WANG
Published: February 2011

Abstract: The Tunggurian Age was nominated in 1984, and the Second National Commission on Stratigraphy of China formally suggested establishing the corresponding chronostratigraphic unit, the Tunggurian Stage, based on the Tunggurian Age in 1999. The name of this stage comes from a lithostratigraphic unit, the Tunggur Formation, and the stratotype section is located at the Tunggur tableland, 15 km southeast of Saihan Gobi Township, Sonid Left Banner, Inner Mongolia. The Tunggurian Age is correlated to the Astaracian of the European land mammal ages, and they share the same definition of the lower boundary at the base of the paleomagnetic Chron C5Bn.1r with an age of 15.0 Ma. In the Tairum Nor section on the southeastern edge of the Tunggur tableland, this boundary is situated within the successive deposits of reddish‐brown massive mudstone of the lower part of the Tunggur Formation, with a distance of 7.6 m from the base of the grayish‐white sandstones in the middle part of the section. The Tunggurian is approximately correlated to the upper part of the marine Langhian and the marine Serravallian in the International Stratigraphical Chart. The Tunggurian Stage includes two Neogene mammal faunal units, i.e. NMU 6 (MN 6) and NMU 7 (MN 7/8). The Tairum Nor fauna from the Tairum Nor section corresponds to NMU 6, and the Tunggur fauna (senso stricto) from the localities on the northwestern edge of the Tunggur tableland, such as Platybelodon Quarry, Wolf Camp and Moergen, corresponds to NMU 7. Among the Middle Miocene mammalian faunas in China, the Laogou fauna from the Linxia Basin, Gansu, the Quantougou fauna from the Lanzhou Basin, Gansu, the Halamagai fauna from the northern Junggar Basin, Xinjiang, and the Dingjiaergou fauna from Tongxin, Ningxia correspond to NMU 6.
Formation Mechanism and Controlling Factors of Natural Gas Reservoirs of the Jialingjiang Formation in the East Sichuan Basin
Authors: Guangyou ZHU , Shuichang ZHANG , Yingbo LIANG , Guoyuan ZHOU , Zhengjun WANG
Published: February 2011

Abstract: The Lower Triassic Jialingjiang Formation reservoirs are distributed widely in the East Sichuan Basin, which are composed mainly of fractured reservoirs. However, natural gas with high concentration of H2S, ranging from 4% to 7%, was discovered in the Wolonghe Gas pool consisting primarily of porous reservoirs, while the other over 20 fractured gas reservoirs have comparatively low, tiny and even no H2S within natural gases. Researches have proved the H2S of the above reservoirs are all from the TSR origin. Most of the Jialingjiang Formation natural gases are mainly generated from Lower Permian carbonate rocks, the Wolonghe gas pool's natural gases are from the Upper Permian Longtan Formation, and the natural gases of the Huangcaoxia and Fuchengzhai gas pools are all from Lower Silurian mudstone. The formation of H2S is controlled by the characteristics and temperature of reservoirs, and is not necessarily related with gas sources. The Jialingjiang Formation in East Sichuan is buried deeply and its reservoir temperature has ever attained the condition of the TSR reaction. Due to poor reservoir potential, most of the gas pools do not have enough room for hydrocarbon reaction except for the Wolonghe gas pool, and thus natural gases with high H2S concentration are difficult to be generated abundantly. The south part of East Sichuan did not generate natural gases with high H2S concentration because the reservoir was buried relatively shallow, and did not suffer high temperature. Hence, while predicting the distribution of H2S, the characteristics and temperature of reservoirs are the necessary factors to be considerd besides the existence of anhydrite.
A New Species of the Ankylosaurid Dinosaur Crichtonsaurus (Ankylosauridae: Ankylosauria) from the Cretaceous of Liaoning Province, China
Authors: Junchang LÜ , Qiang JI , Yubo GAO , Zhixin LI
Published: February 2011

Abstract: A new ankylosaurid species of Crichtonsaurus, C. benxiensis sp. nov., is erected based on a well preserved skeleton and a nearly complete skull found in the Sunjiawan Formation (Cenomanian‐Turonian), Beipiao, Liaoning Province. Crichtonsaurus benxiensis sp. nov. is characterized by width 84.6% of length of the skull, a deep depression located medial to the notch between the orbit and the squamosal horn, paroccipital processes fused to the quadrates, fused scapula and coracoid, a large foramen for the supracoracoid nerve to enter the coracoid and to exit out from the scapula. Based on the new specimen, Crichtonsaurus is assigned to Ankylosauridae.
Discovery of Pseudofrenelopsis gansuensis from the Lower Cretaceous of Wangqing, Jilin Province, and Its Significance in Correlation of Cretaceous Red Beds in China
Authors: Xiaoju YANG , Shenghui DENG
Published: February 2011

Abstract: New data from abundant vegetative shoots and cuticular analysis are provided for the Cretaceous cheirolepidiaceous conifer Pseudofrenelopsis gansuensis Deng, Yang et Lu. The material was found from a new locality of the Lower Cretaceous strata in the Luozigou Basin, Wangqing, Jilin Province, northeastern China. Pseudofrenelopsis is a common plant in the Dalazi Formation of the Yanji Basin about 150 km from Wangqing, but there exists different species, Pseudofrenelopsis dalatzensis only. Both P. dalatzensis and P. gansuensis have been recorded from the Lower Cretaceous of Jiuquan, Gansu Province, but they are in different stratigraphic horizons. The Lower Cretaceous plant‐bearing strata in Luozigou have used to correlate with the Dalazi Formation of the Yanji Basin. The discovery of P. gansuensis, which is lower in horizon than P. dalatzensis in Jiuquan, may indicate that they are also different in horizon in Jilin. Cheirolepidiaceous conifers are among the few fossils of red beds of the Early Cretaceous in China. The present discovery of Pseudofrenelopsis gansuensis provides important evidence for classification, correlation and determination of geological ages of the Early Cretaceous non‐marine red deposits of the two separate basins in remote areas of North China.
Stratigraphy of the Lower Cretaceous Sediments from the Carpathian Bend Area, Romania
Authors: MELINTE‐DOBRINESCU Mihaela‐Carmen , JIPA Dan C.
Published: February 2011

Abstract: The Lower Cretaceous sediments of the Ceahla̧au Nappe (from the bend region of the Romanian Carpathians) were investigated from lithological and micropaleontological (calcareous nannoplankton) points of view. Our investigations revealed that the studied deposits were sedimented within the latest Tithonian‐Albian interval. The calcareous nannofossil assemblages of the turbidite calcareous successions (the Sinaia Formation) were assigned to the NJK‐?NC5 calcareous nannofossil zones, which cover the Late Tithonian‐Early Barremian interval. The sandy‐shaly turbidites, which followed the calcareous turbidites of the Sinaia Formation, are Early Barremian‐Early Albian in age (interval covered by the ?NC5‐NC8 calcareous nannofossil zones). Because the studied deposited are mainly turbidites, many reworked nannofossils from older deposits are present in the calcareous nannofloras. Thus, some biozones (i.e., NC5), defined based on the last occurrences of nannofossils, could not be identified. The calcareous nannofossil assemblages are composed of Tethyan taxa (which dominate the nannofloras) and cosmopolitan taxa. During two intervals (the Late Valanginian and across the Barremian/Aptian boundary), Tethyan and cosmopolitan nannofossils, together with Boreal ones, were observed. This type of mixed calcareous nannoplankton assemblage is indicative for sea‐level high‐stand, which allows the nannofloral exchange between the Tethyan and Boreal reaa̧ms, within the two‐above mentioned intervals.
Basin Fluid Mineralization during Multistage Evolution of the Lanping Sedimentary Basin, Southwestern China
Authors: Xuexiang GU , Yongmei ZHANG , Shuyi DONG , Juxing TANG , Chengshan WANG , Jianping CHEN
Published: February 2011

Abstract: The Lanping sedimentary basin has experienced a five‐stage evolution since the late Paleozoic: ocean‐continent transformation (late Paleozoic to early mid‐Triassic); intracontinental rift basin (late mid‐Triassic to early Jurassic); down‐warped basin (middle to late Jurassic); foreland basin (Cretaceous); and strike‐slip basin (Cenozoic). Three major genetic types of Ag‐Cu polymetallic ore deposits, including the reworked hydrothermal sedimentary, sedimentary‐hydrothermally reworked and hydrothermal vein types, are considered to be the products of basin fluid activity at specific sedimentary‐tectonic evolutionary stages. Tectonic differences of the different evolutionary stages resulted in considerable discrepancy in the mechanisms of formation‐transportation, migration direction and emplacement processes of the basin fluids, thus causing differences in mineralization styles as well as in genetic types of ore deposit.
Response of Reactive Phosphorus Burial to the Sedimentary Transition from Cretaceous Black Shales to Oceanic Red Beds in Southern Tibet
Authors: Yongjian HUANG , Chengshan WANG , Xi CHEN
Published: February 2011

Abstract: The mechanism of sedimentary transition from the Cretaceous black shales to the oceanic red beds is a new and important direction of Cretaceous research. Chemical sequential extraction is applied to study the burial records of reactive phosphorus in the black shale of the Gyabula Formation and oceanic red beds of the Chuangde Formation, Southern Tibet. Results indicate that the principal reactive phosphorus species is the authigenic and carbonate‐associated phosphorus (CaP) in the Gyabula Formation and iron oxides‐associated phosphorus (FeP) in the Chuangde Formation which accounts for more than half of their own total phosphorus content. While the authigenic and carbonate‐associated phosphorus (CaP) is almost equal in the two Formations; the iron oxides‐associated phosphorus is about 1.6 times higher in the Chuangde Formation than that in the Gyabula Formation resulting in a higher content of the total phosphorus in the Chuangde Formation. According to the observations on the marine phosphorus cycle in Modern Ocean, it is found that preferential burial and regeneration of reactive phosphorus corresponds to highly oxic and reducing conditions, respectively, leading to the different distribution of phosphorus in these two distinct type of marine sediments. It is the redox‐sensitive behavior of phosphorus cycle to the different redox conditions in the ocean and the controlling effects of phosphorus to the marine production that stimulate the local sedimentary transition from the Cretaceous black shale to the oceanic red beds.
Stable Carbon Isotopic Compositions of Methylated‐MTTC in Crude Oils from Saline Lacustrine Depositional Environment: Source Implications
Authors: Hong LU , Linhui HOU , Tengshui CHEN , Ping'an PENG , Guoying SHENG
Published: February 2011

Abstract: Significantly high abundant methyl‐MethylTrimethylTridecylChromans (MTTCs) have been detected in aromatic hydrocarbon fractions in crude oils from the Jizhong Depression and Jianghan Basin. The distribution of these compounds is dominated by methyl‐MTTC and dimethyl‐MTTC series, which indicate diagenetic products of a hypersaline depositional environment in the early stage and show a low degree of methylation. The occurrence of significantly high abundant methyl‐MTTC depends mainly on good preservation conditions with a strongly reductive, hypersaline and water‐columned depositional environment and subsequent non‐intensive diagenetic transformations. The stable carbon isotopic compositions of the methyl‐MTTCs and dimethyl‐MTTCs in two samples are far different from the stable carbon isotopic composition of C30 hopane of apparent bacteria biogenesis (up to 4.11%a̧ and 5.75%a̧, respectively). This obviously demonstrates that the methyl‐MTTC and dimethyl‐MTTCs cannot be of bacteria origin, which is different from the previous point of view about non‐photosynthetic bacteria products or possible bacteria‐reworked products. On the contrary, the stable carbon isotopic compositions of methyl‐MTTC and dimethyl‐MTTCs in the two samples were similar to that of the same carbon‐numbered n‐alkanes (nC27‐nC28‐nC29), which indicates that they share the same source origin. Especially in the crude oil from the Zhao61 well, stable carbon isotopic compositions are also similar to that of the same carbon‐numbered steranes with ααα‐20R isomer (mostly less than 0.4%). In consideration of the results of previous studies on saline lake ecological sedimentation, the authors hold that the methyl‐MTTC and dimethyl‐MTTCs in the saline lake sediments should be of algal biogenesis origin.
A New SHRIMP Age of the Xiamaling Formation in the North China Plate and Its Geological Significance
Authors: Linzhi GAO , Chuanheng ZHANG , Xiaoying SHI , Hongrui ZHOU , Ziqiang WANG , Biao SONG
Published: February 2011

Abstract: Setting up the hypostratotype of late Precambrian is the main aim of the research on the Meso‐ and Neoproterozoic in North China. The chronostratigraphic position is the key in this study. However, many key horizons have not been calibrated with the high‐quality isotopic ages. Using the reported new U‐Pb age with the Sensitive High‐Resolution Ion Microprobe (SHRIMP II), a zircon U‐Pb age was obtained of the ash bed in the Xiamaling Formation in North China Plate, yielding a weighted mean 206Pb/238U age of 1368±12 Ma. It is the first SHRIMP U‐Pb age from the Xiamaling Formation in the North China Plate, and represents the depositing time of the middle part of the Xiamaling Formation. The zircon age plays an important role to understanding geological evolution of the North China Plate during Meso‐ and Neoproterozoic.
Parametric Numerical Study of Flow and Heat Transfer in Microchannels With Wavy Walls
Authors: Gong Liang , Kota Krishna , Tao Wenquan , Joshi Yogendra
Published: February 2011

Wavy channels were investigated in this paper as a passive scheme to improve the heat transfer performance of laminar fluid flow as applied to microchannel heat sinks. Parametric study of three-dimensional laminar fluid flow and heat transfer characteristics in microsized wavy channels was performed by varying the wavy feature amplitude, wavelength, and aspect ratio for different Reynolds numbers between 50 and 150. Two different types of wavy channels were considered and their thermal performance for a constant heat flux of 47 W/cm2 was compared. Based on the comparison with straight channels, it was found that wavy channels can provide improved overall thermal performance. In addition, it was observed that wavy channels with a configuration in which crests and troughs face each other alternately (serpentine channels) were found to show an edge in thermal performance over the configuration where crests and troughs directly face each other. The best configuration considered in this paper was found to provide an improvement of up to 55% in the overall performance compared to microchannels with straight walls and hence are attractive candidates for cooling of future high heat flux electronics.
Nanorobot Propulsion Using Helical Elastic Filaments at Low Reynolds Numbers
Authors: K. Deepak , Rathore J. S. , Sharma N. N.
Published: February 2011

Swimming in micro/nano domains is a challenge and involves a departure from standard methods of propulsion, which are effective at macrodomains. Flagella based propulsion is seen extensively in nature and has been proposed as a means of propelling nanorobots. Natural flagella actively consume energy in order to generate bending moments that sustain constant or increasing amplitude along their length. However, for man-made applications fabricating passive elastic filaments to function as flagella is more feasible. Of the two methods of flagellar propulsion, namely, planar wave and helical wave, the former has been studied from a passive filament point of view, whereas the latter is largely unexplored. In the present work an elastohydrodynamic model of the filament has been created and the same is used to obtain the steady state shape of an elastic filament driven in a Stokes flow regime. A modified resistive force theory, which is very effective in predicting propulsion parameters for a given shape, is used to study the propulsive dynamics of such a filament. The effect of boundary conditions of the filament on determining its final shape and propulsive characteristics are investigated. Optimization of physical parameters is carried out for each of the boundary conditions considered. The same are compared with the planar wave model.
Lumen Irregularity Dominates the Relationship Between Mechanical Stress Condition, Fibrous-Cap Thickness, and Lumen Curvature in Carotid Atherosclerotic Plaque
Authors: Teng Zhongzhao , Sadat Umar , Ji Guangyu , Zhu Chengcheng , Young Victoria E. , Graves Martin J. , Gillard Jonathan H.
Published: February 2011

High mechanical stress condition over the fibrous cap (FC) has been widely accepted as a contributor to plaque rupture. The relationships between the stress, lumen curvature, and FC thickness have not been explored in detail. In this study, we investigate lumen irregularity-dependent relationships between mechanical stress conditions, local FC thickness (LTFC), and lumen curvature (LClumen). Magnetic resonance imaging slices of carotid plaque from 100 patients with delineated atherosclerotic components were used. Two-dimensional structure-only finite element simulations were performed for the mechanical analysis, and maximum principal stress (stress-P1) at all integral nodes along the lumen was obtained. LTFC and LClumen were computed using the segmented contour. The lumen irregularity (L-δir) was defined as the difference between the largest and the smallest lumen curvature. The results indicated that the relationship between stress-P1, LTFC, and LClumen is largely dependent on L-δir. When L-δir≥1.31 (irregular lumen), stress-P1 strongly correlated with lumen curvature and had a weak/no correlation with local FC thickness, and in 73.4% of magnetic resonance (MR) slices, the critical stress (maximum of stress-P1 over the diseased region) was found at the site where the lumen curvature was large. When L-δir≤0.28 (relatively round lumen), stress-P1 showed a strong correlation with local FC thickness but weak/no correlation with lumen curvature, and in 71.7% of MR slices, the critical stress was located at the site of minimum FC thickness. Using lumen irregularity as a method of identifying vulnerable plaque sites by referring to the lumen shape is a novel and simple method, which can be used for mechanics-based plaque vulnerability assessment.
Radial compression studies of WS2 nanotubes in the elastic regime
Authors: Kalfon-Cohen Estelle , Goldbart Ohad , Schreiber Roy , Cohen Sidney R. , Barlam David , Lorenz Tommy , Enyashin Andrey , Seifert Gotthard
Published: February 2011

Multiwalled nanotubes and nanoparticles of metal dichalcogenides express unique mechanical and tribological characteristics. A widely studied member of this class of materials is the WS2 nanotube whose structure consists of layers of covalent W-S bonds joined by the van der Waals interactions between the sulfur layers which mediate any interlayer sliding or compression. One of the intriguing aspects of these structures is the response of these layers under mechanical stress. Such internal degrees of freedom can profoundly impact on the overall mechanical response. The fact that the internal structure of these nanotubes is well characterized enables a full treatment of the problem. Here, the authors report an experimental and modeling study of the radial mode of deformation. Three independent atomic force microscope experiments were employed to measure the nanomechanical response using both large (radius=100 nm) and small (radius=3–15 nm) probe tips. Two different analytical models were applied to analyze the results. The modulus values derived from the analytical models were used as initial input for a finite element analysis model to yield a refined value of this parameter. The obtained values compare favorably with density functional tight binding calculations. The results indicate a strong influence of interwall shear on the radial modulus.
Vibrationally Quantum-State–Specific Reaction Dynamics of H Atom Abstraction by CN Radical in Solution
Authors: Greaves Stuart J. , Rose Rebecca A. , Oliver Thomas A. A. , Glowacki David R. , Ashfold Michael N. R. , Harvey Jeremy N. , Clark Ian P. , Greetham Gregory M. , Parker Anthony W. , Towrie Michael , Orr-Ewing Andrew J.
Published: February 2011

Molecular vibrations in a solution-phase reaction are detected at a level of detail rivaling that of gas-phase studies.
Cascading Effects of Bird Functional Extinction Reduce Pollination and Plant Density
Authors: Anderson Sandra H. , Kelly Dave , Ladley Jenny J. , Molloy Sue , Terry Jon
Published: February 2011

Loss of pollinator services is reducing the population density of a New Zealand shrub.
A Translational Pause to Localize
Authors: Ron David , Ito Koreaki
Published: February 2011

Cells optimize the response to protein stress by controlling the localization and splicing of an mRNA that encodes a transcription factor.
Can Obama Strike a Deal With House Republicans?
Authors: Mervis Jeffrey
Published: February 2011

Science
talked with three Republican House members with seats on committees that oversee science about possible areas of agreement with the White House. Their answers suggest there may be some room for compromise on how best to foster innovation.
USDA Decides Against New Regulation of GM Crops
Authors: Stokstad Erik
Published: February 2011

After nearly 4 years of a court-imposed ban, U.S. farmers will once again be able to plant genetically modified alfalfa. The high-stakes decision was announced last week by the U.S. Department of Agriculture.
Assessment of Five Antigens from Mycobacterium tuberculosis for Serodiagnosis of Tuberculosis
Authors: He Xiu-Yun , Li Jing , Hao Juan , Chen Hong-Bing , Zhao Ya-Zhen , Huang Xiang-Yu , He Ke , Xiao Li , Ye Li-Ping , Qu Yi-Mei , Ge Lin-Hu
Published: February 2011

Tuberculosis (TB), caused byMycobacterium tuberculosis, is a major public health issue, particularly in developing countries, and thus effective diagnostic methods for TB remain a central theme in basic and clinical research. To evaluate five antigens (38-kDa protein [38kDa], Rv3621c, Rv3618, 38kDa-ESAT-6 [38E6], and Ag85B-HBHA [AH]) in serological tests for TB patients, we recruited 288 patients and 201 healthy controls. The median IgG reactivity to 38kDa, 38E6, and AH was higher than that to Rv3618 and Rv3621c in pulmonary TB. 38kDa and 38E6 provided high sensitivities in pulmonary TB but low sensitivities in extrapulmonary TB (EPTB). The specificities achieved by 38kDa and 38E6 ranged from 82.0% to 93.9% in patients with non-TB respiratory disease (PD) and in controls. 38kDa and 38E6 exhibited lower sensitivities and higher specificities than their combinations with Rv3618. These findings provide useful information on the relative importance of the above five antigens and suggest that combinations of Rv3618 with 38kDa and 38E6 can increase their sensitivities, but their specificities need to be further increased.
Mutation Detection and Accurate Diagnosis of Extensively Drug-Resistant Tuberculosis: Report from a Tertiary Care Center in India
Authors: Ajbani Kanchan , Rodrigues Camilla , Shenai Shubhada , Mehta Ajita
Published: February 2011

We screened and spoligotyped 150 consecutive phenotypically confirmed extensively drug-resistant
Mycobacterium tuberculosis
(XDR-TB) isolates (January 2008 to March 2009) for rifampin, isoniazid, fluoroquinolone, and aminoglycoside resistance targeting
rpoB
,
inhA
,
katG
,
gyrA
,
gyrB
, and
rrs
. Mutations predominant among XDR-TB were S315T (
katG
) (100% of isolates), S531L (
rpoB
) (97% of isolates), D94G (
gyrA
) (53% of isolates), and A1401G (
rrs
) (71% of isolates). Spoligotyping revealed 62% of the isolates to be Beijing.
Chronic Q Fever-Related Dual-Pathogen Endocarditis: Case Series of Three Patients
Authors: Kampschreur Linda M. , Oosterheert Jan Jelrik , de Vries Feyens Cornelia A. , Delsing Corine E. , Hermans Mirjam H. A. , van Sluisveld Ingrid L. L. , Lestrade Peter J. , Renders Nicole H. M. , Elsman Peter , Wever Peter C.
Published: February 2011

Following
Coxiella burnetii
infection, there is a 1 to 5% risk of chronic Q fever. Endocarditis, mycotic aneurysm, and vascular prosthesis infection are common manifestations. We present three patients with endocarditis by
C. burnetii
concomitant with another bacterial pathogen. Chronic Q fever should therefore be considered in all endocarditis patients in regions where Q fever is endemic.
Interaction of Autographa californica Multiple Nucleopolyhedrovirus Cathepsin Protease Progenitor (proV-CATH) with Insect Baculovirus Chitinase as a Mechanism for proV-CATH Cellular Retention
Authors: Hodgson Jeffrey J. , Arif Basil M. , Krell Peter J.
Published: February 2011

The insect baculovirus chitinase (CHIA) and cathepsin protease (V-CATH) enzymes cause terminal host insect liquefaction, enhancing the dissemination of progeny virions away from the host cadavers. Regulated and delayed cellular release of these host tissue-degrading enzymes ensures that liquefaction starts only after optimal viral replication has occurred. Baculoviral CHIA remains intracellular due to its C-terminal KDEL endoplasmic reticulum (ER) retention motif. However, the mechanism for cellular retention of the inactive V-CATH progenitor (proV-CATH) has not yet been determined. Signal peptide cleavage occurs upon cotranslational ER import of the
v-cath
-expressed protein, and ER-resident CHIA is needed for the folding of proV-CATH. Although this implies that CHIA and proV-CATH bind each other in the ER, the putative CHIA–proV-CATH interaction has not been experimentally verified. We demonstrate that the amino-terminal 22 amino acids (aa) of
Autographa californica
multiple nucleopolyhedrovirus (AcMNPV) preproV-CATH are responsible for the entry of proV-CATH into the ER. Furthermore, the CHIA–green fluorescent protein (GFP) and proV-CATH-red fluorescent protein (RFP) fusion proteins colocalize in the ER. Using monomeric RFP (mRFP)-based bimolecular fluorescence complementation (BiFC), we determined that CHIA and proV-CATH interact directly with each other in the ER during virus replication. Moreover, reciprocal Ni/His pulldowns of His-tagged proteins confirmed the CHIA–proV-CATH interaction biochemically. The reciprocal copurification of CHIA and proV-CATH suggests a specific CHIA–proV-CATH interaction and corroborates our BiFC data. Deletion of the CHIA KDEL motif allowed for premature CHIA secretion from cells, and proV-CATH was similarly prematurely secreted from cells along with ΔKDEL-CHIA. These data suggest that CHIA and proV-CATH interact directly with each other and that this interaction aids the cellular retention of proV-CATH.
Psychogeometrics and behaviour assessment techniques
Authors: Leyland Alan
Published: February 2011

Is psychogeometric testing relevant to the veterinary profession? While it may be viewed with suspicion or indifference by some, it is valued by many commercial companies and government organisations. Alan Leyland outlines two testing techniques and discusses how they may be used by practices.
Comments on the dilemma in the January issue: ‘Farm cat with TB’
Authors: Mullan Siobhan
Published: February 2011

The dilemma in the January issue concerned a pet cat that had been diagnosed with tuberculosis on a dairy farm (In Practice, January 2011, volume 33, pages 46–47). The cat was a much‐loved pet of the farmer's young daughter. Martha Cannon commented that factors to be considered included the effect on the quality and quantity of the life of the cat and its owners, as well as the financial implications for the farm. While Mycobacterium bovis was a potentially zoonotic infection, the risk of spread from cats to humans appeared to be small, but was not non‐existent. It was also unlikely that the cat would be a source of infection to the cattle. Treating the cat was not a straightforward option and the prognosis was unlikely to be good. Euthanasing the cat would affect family members in different ways and could involve sadness, grief, guilt or even relief. A possible way forward would be to make the owners aware of the small potential risk to their health from ongoing contact with the cat, and ensure they consider the practicalities of dosing their cat with several drugs twice daily, every day for six to 12 weeks. If the decision was made to opt for euthanasia, the young daughter should be involved in the discussion and must be made aware that the decision was reached in the cat's best interests to prevent future distress, rather than for financial reasons relating to the dairy herd.
Cerebrospinal fluid: analysis and interpretation in small animals
Authors: Lowrie Mark , Anderson James
Published: February 2011

Cerebrospinal fluid (CSF) bathes the brain and spinal cord, which are ensheathed by the meninges. Any disease occurring within this compartment has the potential to alter the characteristics of this fluid. CSF analysis forms part of the diagnostic evaluation of animals with neurological disease. It is especially useful for the diagnosis of inflammatory diseases such as meningitis, encephalitis or myelitis that affect the central nervous system, the surrounding meninges and nerve roots. This article describes the indications for performing CSF analysis and describes the techniques that can be employed to obtain a sample. It explains how to handle and analyse CSF samples, with particular emphasis on cytological interpretation. Examples of diseases in which CSF analysis is essential in obtaining a definitive diagnosis are used to illustrate the importance of this procedure.