New media, the new economy and new spaces

This paper counters proponents of the ‘weightless economy’ who have suggested the ‘death of distance’ in relation to economic and social activities that use the worldwide web (WWW). An analysis of new media developers in New York’s ‘Silicon Alley’ demonstrates that place and distance are still important. The most important aspect of this co-location is the possibility of social interaction. This paper points to the value of analysis of the material practice of the social (and the economic and cultural). The notion of ‘untraded dependencies’ is developed through looking at its manifestation and constitution in the specificity of space, time and economic activity.     

跨入新世纪 迎接新挑战

本文分析了21世纪铀矿地质科研面临的新形势，提出今后工作的总体方针是认真贯彻中央精神，具体落实中核集团提出的目标任务，在成矿理论的创新与发展，传统与非传统矿产资源的勘查与开发利用，矿业开发与环境保护的协调发展等研究领域有新的突破。文章强调了大规模成矿作用及大型矿集区预测研究的重要性，认为应加强学科交叉和学术交流活动，争取良好的政策环境，保持必要的投资强度，培养和造就一批年轻的技术骨干和学科带头人，以崭新的姿态迎接21世纪的挑战。     

新世纪伊始的中国矿业

主席先生，各位代表，女士们，先生们：在金秋的９月，我们相聚在美丽的古都西安。西安是中国第一个封建王朝及多达１２个王朝的首都，是历史上中华民族鼎盛时期的经济、文化和政治中心。从恢宏的兵马俑阵到青铜战车和兵器，折射着近１８００年前中国古文化和中国古矿业的发展水平。从这个意义上讲，没有发达的古矿业，就没有古都西安。从青铜器到铁器，再到工业革命，矿业支撑着人类文明的发展。在进入２１世纪的今天，矿业依然对人类社会和经济的发展起着巨大的支撑作用。这也是我们汇聚一堂共计中国矿业发展和中国矿业应该对世界经济发展…     

一种新的海进模式

一种新的海进模式龚一鸣（中国地质大学地史教研室，湖北武汉，４３００７４）关键词海进，地层，沉积，模式一、实例和问题海进又名海侵，是地质学中基本的地质现象和过程。自Ｗａｌｔｈｅｒ（１８９４）从理性角度赋予海进概念的地层学和沉积学意义以来，它就以人们广泛...     

IUGS elects new officers

At the Ist Ordinary Session of the merged IUGS/IGC Council, held in Florence, Italy, in conjunction with the 32nd International Geological Congress (IGC), the following new officers were elected:     

西藏达雄群的化石新资料和再认识

在达雄群中新发现的双壳Ludbrookiadaxungensis,L.daxungensis,Rasatrixcf.suzulii,Arcticasubextensa及腹足Biplicaobliqu等化石,具早白垩世动物群组合面貌,表明该群的沉积时代大致为早白垩世欧特里夫—阿尔布期(Hauterivian-Albrian),而不是前人划归的中—晚侏罗世,与区内的早白垩世则弄群上部相当。     

矿产勘查新理论与新方法综述

近十年来，矿产勘查新理论和新方法层出不穷，本文系统地总结了目前矿产勘查的新理论和新方法，并展望其与高新技术相结合的发展前景。介绍了新的成矿理论，主要有地球化学障成矿、陨击成矿、地幔柱成矿、边缘成矿和海底成矿理论；新方法主要有预测沉积矿产的古地磁法、预测铅、铀矿稳定同位素法、气体测量法、预测卡林型金矿的顺磁共振法以及应用于寻找隐伏矿床的元素活态提取法和金属地震法等等。     

Caves: new and old

Caves represent underground drainage routes formed by the passage of water through soluble rocks. Caves and the deposits they contain preserve evidence of landscape evolution and climatic change together with sediments and fossils that elsewhere have been destroyed by erosion.     

A new look at rifts

Rift valleys have always enthralled geologists. They are the rents in the Earth's crust produced when continental plates pull apart. Besides telling us something about the evolution of our planet, they also act as topographic sumps in which parts of the sedimentary record of Earth history are often best preserved. Yet our understanding of how, where, and why rifts form has only recently come of age with new models of structure and sedimentation.     

A new view on neotectonics

Conclusion Neotectonics — the discipline examining the youngest history of the Earth in terms of geotectonics — should be complemented by aspects based on other geological sciences (geochemistry, geophysics) as well as geography and geodesy. From the viewpoint of the Earth's history, neotectonics can be regarded as a discipline studying, above all, the Earth's crust and the changes that occurred there in the time span from the Badenian to the Recent. For this reason, the last phase of the Alpine geotectonic stage, which extended from the Oligocene to the base of the Lower Badenian, should be termed pre-neotectonics.     

A new global topographic-isostatic model

This is a preliminary report of our on-going research on a global topographic-isostatic model. The model comes from a completely new idea — the geoid undulation is the responses of an elastic earth to the topographic mass load. Assuming the topography as a condensed surface mass load, we derive expressions for calculating the vertical displacement, potential and equipotential surface changes, based on the load theory proposed in Sun and Sjöberg (1996). The modeled geoid is composed of three parts: loading potential, surface displacement and mass redistribution. The mass redistribution of the earth compensates to some extent the topography. We mainly calculate and discuss the vertical displacements and equipotential surface changes for three depths: the earth's surface, d = 36 km and the core-mantle boundary. Numerical results show that the displacements at depth 36 km and the earth's surface have the same distribution pattern and magnitude, while the vertical movement of the core-mantle boundary appears much smoother and smaller. The modeled geoid undulations vary between −352 and +555 m. The comparison between the modeled and observed geoid undulations shows that there are strong positive correlations between them, but a compensation only by elastic deformations is not sufficient to explain the observed undulations because of the big difference in magnitude between the two geoids. More geodynamic effects should be considered to better explain the long-wavelength geoid features.