Dinosaur coprolites from the Late Cretaceous (Maastrichtian) Lameta Formation of India: isotopic and other markers suggesting a C₃plant diet     

Prosenjit Ghosh  S. K. Bhattacharya  Ashok Sahni  R. K. Kar  D. M. Mohabey  K. Ambwani 《Cretaceous Research》2003,24(6):743-750

A single locality of the Late Cretaceous (Maastrichtian) Lameta Formation at Pisdura in Central India has yielded a large number of coprolites attributed to titanosaurian dinosaurs. Internally the coprolites are dark grey and contain abundant plant tissues and other organic materials. The plant tissues are mostly of gymnospermous origin. In addition, remains of bacterial colonies, fungal spores and algae are seen in the macerated fraction under scanning electron microscope. The dark grey appearance is probably attributable to fine-grained organic matter within voids in tracheids or xylem. The average ¹³C/¹²C ratio of the organic matter in the coprolites is -24‰ (relative to PDB) suggesting that plants of C₃type were the main diet of their producers. A comparison of δ¹⁵N value (about 4‰ w.r.t. air) of the coprolites with that of faecal matter of modern herbivores and carnivores suggests that gut fermentation may not have been an active mechanism in the digestion process of titanosaurs.  相似文献   

中尺度模式中各种湿物理过程的数值模拟   总被引：14，自引：1，他引：14  

康丽莉  雷恒池  肖稳安 《南京气象学院学报》2003,26(1):76-83

利用PSU／NCAR的MM5对1999年6月下旬发生在江淮流域的梅雨锋暴雨进行数值模拟试验，研究MM5中不同湿物理过程中对MM5模拟梅雨锋暴雨的影响。试验结果显示：中尺度模式MM5能一定程度再现一些观测的中尺度特征，对流参数化方案对网格格距的大小比较敏感；显式云物理方案考虑冰相后可明显改善模式对暴雨的模拟能力，尤其是采用Reisner包含霰的混合相双变参数谱方案的双重嵌套网格对降水量的模拟取得较好的效果。  相似文献   

A　Comparative　Study　of　the　Atmospheric　Layers　below　First　Lifting　Condensation　Level　for　Instantaneous　Pre-Monsoon　Thunderstorm　Ocurence　at　Agartala(23°30′N,91°15′E)　and　Ranchi(23°14′N,85°14′E)　of　India     

Sarbari Ghosh  Utpal Kumar De Atmospheric Science Research  Department of Physics  Jadavpur University  Calcutta  India Received April    revised July   《大气科学进展》1997,(1)

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Evidence for the thrust emplacement of the ‘Lesser Himalaya’ Chur granite,Himachal Pradesh     

Dilip K Mukhopadhyay  Bidyut K Bhadra  Tamal K Ghosh  Deepak C Srivastava 《Journal of Earth System Science》1996,105(2):157-171

Numerous peraluminous and porphyritic granitic bodies and augen gneisses of granitic compositions occur in the nappe sequences of the Lower Himalaya. They are Proterozoic-to-lower Paleozoic in age and have been grouped into the ‘Lesser Himalaya granite belt’. The mode of emplacement and tectonic significance of these granites are as yet uncertain but they are generally considered to be sheet-like intrusions into the surrounding rocks. The small and isolated granite body (the Chur granite) that crops out around the Chur peak in the Himachal Himalaya is one of the more famous of these granites. Several lines of evidence have been adduced to show that the Chur granite has a thrust (the Chur thrust) contact with the underlying metasedimentary sequence (locally called the Jutogh Group). The Chur granite with restricted occurrence at the highest topographic and structural levels represents an erosional remnant of a much larger sub-horizontal thrust sheet. The contact relations between the country rocks and many of the other granite and granitic augen gneisses in the Lesser Himalaya belt are apparently similar to that of the Chur granite suggesting that at least some of them may also represent thrust sheets.  相似文献   

新疆阿尔曼太蛇绿岩时代的Nd—Sr同位素地质研究   总被引：15，自引：7，他引：15  

黄萱  金成伟 《岩石学报》1997,13(1):85-91

本文通过测定采自新疆阿尔曼太兔子泉一带蛇绿岩的堆晶辉长岩、辉绿岩和安山玢岩，获得Ｓｍ－Ｎｄ等时年龄为５６１±４１Ｍａ，εＮｄ（ｔ）＝６．１，Ｒｂ－Ｓｒ等时年龄为３９２±１７Ｍａ，（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０４１，前者为蛇绿岩的形成时代，后者为蛇绿岩遭受后期变质作用的时间。札河坝－阿尔曼太蛇绿岩的形成环境可能是古亚洲洋向南俯冲引起的弧后盆地  相似文献   

Research on Relationship Between Fluorine in Tap Water and That in Urine of Chinese Residents     

王滨滨  郑宝山  翟城  刘小静  安宁 《中国地球化学学报》2004,23(4):373-379

In this study, the relationship between fluorine in drinking water and that in urine of urban residents in China is assessed. Fluorine concentrations in tap water and those in urine show a good correlation with a linear regression coefficient of 0. 9798, indicating that the fluorine concentrations in big cities under investigation are extremely low, and the main source of fluorine is tap water. The weather effect on the intake amount of fluorine is also discussed. When air temperature is above 15℃, people would intake more fluorine through drinking water with the rise of air temperature. When temperature is below 15℃, no remarkable relationship is observed between air temperature and the intake amount of fluorine. This phenomenon indicates that the main source of fluorine in China is tap water instead of foodstuff.  相似文献   

北山戈壁荒漠景观1∶5万地球化学测量方法研究   总被引：1，自引：0，他引：1  

康明  岑况  吴悦斌  沈镛立  叶荣 《地质与勘探》2004,(3)

通过在西北北山地区进行剖面和面积性方法试验,研制出了一套适合于西北荒漠戈壁景观条件的地球化学测量方法,即包括样品布局、采样密度、样品介质、样品粒级以及不同类型的地球化学测量方法技术。试验结果证实,每平方千米采集>20目的沟谷粗碎屑介质样品,能够圈定出清晰的矿化异常,而且异常元素组合齐全,指示意义明确,较准确地反映了矿体或矿化体的形态和延伸方向。同时辅助采集植物———红莎样品和<80目细粒级样品(提供热释汞分析),可以提取掩埋矿化体的信息。  相似文献   

酿酒葡萄冻害原因的初步分析及防御对策   总被引：5，自引：0，他引：5  

常绪正张慧  康永义 《沙漠与绿洲气象(新疆气象)》2004,27(4):27-30

通过对酿酒葡萄冻害的调查研究分析指出：初霜冻的早晚和冬季的极端低温不是造成酿酒葡萄冻害的主要原因。品种间差异和栽培管理不同也不是造成酿酒葡萄冻害的主要原因，10月份的强降温、气温明显偏低(气温≤-5．2℃)才是酿酒葡萄树体冻害的主要原因。引种抗冻能力较强酿酒葡萄品种、选择适应的生长环境和掌握适宜的埋土时间，是防御酿酒葡萄冻害防御的主要对策。  相似文献   

牡丹江市大--暴雨中期预报方法研究     

邢丽燕  车正浩  李莉 《黑龙江气象》2004,(3):4-5

应用MICAPS平台所提供的数值预报产品，分析影响牡丹江市大一暴雨的天气系统，并找出关键区域及预报指标，在实际预报中取得了很好的效果。  相似文献   

基于遥感信息的土地资源可持续利用研究   总被引：1，自引：0，他引：1  

周媛  邢立新 《世界地质》2004,23(2):175-178

遥感信息是对自然界的反映，它具有宏观、动态、准确、快速的优点，可以及时提供动态数据。基于遥感信息，对吉林西部土地资源利用状况进行调查，运用主成分分析法，可以不损失或很少损失原有的信息，将原来个数较多而且彼此相关的变量转换为新的个数较少而且彼此独立或不相关的新变量。对土地资源可持续利用进行定量分析研究，指出土地利用中存在的问题，并提出吉林西部土地资源可持续利用发展模式。  相似文献