珠江三角洲沉积相序

珠江三角洲是在晚更新世玉木亚间冰期和全新世大西洋期,由多条河流的泥、沙输入溺谷型河口湾内,形成具不同沉积特征的叠覆、镶嵌复合体,经历了由河口湾沉积向河控三角洲沉积的演变.其沉积相序分两类:一类是玉木亚间冰期和大西洋海侵阶段,形成以潮汐作用为主的溺谷型河口湾沉积相序,属海侵层序;另一类为大西洋期海平面相对稳定以来,以迳流作用为主的进积型河控三角洲沉积相序.     

侏罗纪大洋缺氧事件中气体水合物的大量分解

欧洲贫有机物的海洋碳酸盐可以很好地说明众所周知的托阿尔早期的碳同位素正偏移 ,而海洋有机质以及相关的碳酸盐则主要记录了负偏移（以前认为后者主要为成岩成因）。缺失有机物的特提斯期灰岩的碳同位素也存在负偏移 ,其在阿尔伯特阶则极少出现。总之 ,这些δ１３Ｃ曲线记录了一个同位素值缓慢上升的阶段 ,其同位素值首先被一个负偏移间断 ,然后突然变为正偏移。英格兰约克郡的ＨａｗｓｋｅｒＢｏｔｔｏｍｓ剖面提供了海洋有机物中负偏移的详细资料。这种偏移与黑页岩沉积作用和高分辨率鲕状岩生物地层学的关系很容易确定。也出现了木化石…     

Geographic and temporal variations of sulfate aerosols over the Pacific Ocean

To investigate the life cycle of marine sulfate aerosols, chemicophysical characteristics of marine aerosolswere measured during five cruises in the Pacific Ocean. Dimethyl sulfide concentrations in seawater and in the air were also measured. The geographic variation of sulfate-aerosol concentrations was studied in relation to biogenic and anthropogenic sources,transport with air trajectories, and chemical transformations in the atmosphere. The highest concentrations were found near Asian and American ports, indicating anthropogenic pollution is the major sulfate aerosols source. Higher concentrations were observed in the upwelling regions than in the oligotrophic areas. Along the coastal regions, both mass and number concentrations of sulfate aerosols depended on wind direction and wind speed, and land-breeze and sea-breeze oscillations; no clear diurnal variation was detected. In pelagic areas, along the equator, the concentrations of small sulfate particles showed a maximum in the afternoon and the m     

亚马孙河及其河口区中颗粒有机碳的来源和运移

本文将碳同位素比值用于研究亚马孙河及其主要支流中颗粒有机碳(POC)的来源,同时也探讨了河流POC向海洋环境的输送,在亚马孙河上游POC的碳同位索值δ13C(-24.5——28.0‰)较之在其中下游的相应值(-27.9——30.1‰)要重一些一般来说,其支流POC的同位素组成要比在亚马孙河主航道中测得的值要轻一些由碳同位素数据证明,亚马孙河主航道中POC的主要来源是陆地物质,而不是河生生物,在亚马孙河口区和淡水舌中观测到POC的同位素组成有很大的变化范围(-17.5——28.4‰),这被认为是河流的POC与海洋的POC在该区域中混合作用的结果.由同位素数据可计算出河流有机碎屑沿平行于河流航道方向向海可搬运至距河口290km处,而沿亚马孙河淡水舌方向在河口西北方向1100km处仍可看到河流POC的稳定同位素信号.     

Chukiang (Shiuchow)-A Study in Urban Geography

Ⅰ.Losatlon and Historical Development Chukiang or “the winding river” was a castle-like town which was originaIly surrounded by a wall.(Fig. 2)it is situated on the upper part of the Peikiang at the iunction of the Teheng and Wu Riwrs, and is on the crossroad both by land and water (Fig. 1). The city was developed as     

Note on The Phosphate Deposits in China

正 The earliest known phosphate deposit in China is the Chinpingshan~1apatite deposit in Tunghai district,~2 N.Kiangsu.During the Sino-Japanesewar,a number of phosphorite deposits were discovered in Central Yunnan     

Distribution and U-Pb Ages of Newly Recognized Regional-Scale Dyke Swarms of the Leo Man Craton

正Over 20 sets of dolerite dykes crosscutting Paleoproterozoic basement in West Africa were distinguished via the interpretation of regional and high resolution magnetic airborne data of West African Craton     

Evaluation of water resources conserved by forests in the Hani rice terraces system of Honghe County,Yunnan, China: an application of the fuzzy comprehensive evaluation model

The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in the sustainable development of this system. The value of water conserved by the forest is influenced by natural, economic and social factors. In this paper, the water quality, per capita water resources, per capita GDP and population density are chosen as indices to construct an index system for a comprehensive evaluation of water resources value. The weights of these indices are 0.443, 0.31, 0.141 and 0.106 respectively, which are determined by the analytic hierarchy process(AHP) method. The water resources value has been assessed by the fuzzy comprehensive evaluation model. The results show that the water resources value in the Hani Rice Terraces System is 4.25 RMB/m~3. Evaluating the value of water resources in the Hani Rice Terraces System can provide a reference for ecological compensation, for raising public awareness of the importance of protecting the system, and ultimately achieving its sustainable development.