松辽分水岭东段白土山组成因与时代

综合考虑松辽分水岭东段地区白土山组的地层分布、沉积特征、地貌部位及第四纪以来松辽分水岭的演化过程、松辽水系的变迁，认为其为河流冲积物，形成时代为早更新世早期。     

对西秦岭拉尔玛地区太阳顶群进一步划分的意见

太阳顶群是一套黑色含碳硅质碎屑岩系，化石贫乏。笔者１９８８年在拉尔玛地区该群拉尔玛组上部发现有ＣｙｌｉｎｄｒｏｃｈｉｔｅｓｄａｉｚｎｕａｎｇｚｉｅｎｓｉｓＬｉｕ和ＨｙｏＬｉｔｈｅｌｌｕｓｑｉｎｇｈｅｅｓｉｓＬｉｕ等微体小壳化石，分别相当于陕西宁强、湖北房县、四川峨嵋麦坪和云南昆明梅树村产的Ｈｙｏｌｉｔｈｅｓｓｐ。和Ａｕａｂａｒｉｔｅｓ－Ｃｉｒｃｏｔｈｅｃａ化石组合，是下寒武统底部梅树村阶的标准带。根据微体小壳化石组合和岩性特征，将原太阳顶群拉尔玛组的上部，以铁质条带硅质板岩风化壳为标志的沉积间断为底界，时代定为下寒武统。将拉尔玛组中下部以下地层，时代定为上震旦统。     

南海磁异常场分区研究──应用人工神经网络方法

首次提出用人工神经网络理论处理磁测资料，进行磁异常场分区的定量计算方法。并将该方法应用于南海研究。该方法将研究区域划分为若干统计单元，确定各统计单元中的特征变量、选择标准模型，并对BP神经网络进行训练。用学习成功的网络识别、分析整个研究区的磁异常场，从而将南海的磁异常场划分为12个特征区。     

Digital Divides in New South Wales: A research note on socio-spatial inequality using 2001 Census data on computer and Internet technology

This paper examines social and spatial inequalities in personal usage of information technologies, drawing on data made available recently as part of Australia's national census, undertaken by the Bureau of Statistics in 2001. Data on both computer and Internet use are analysed in a number of ways: patterns of use and non-use of the technology are examined across New South Wales in relation to a number of variables, including age, place of birth, indigeneity, income and educational status. Selected results are mapped for State-wide trends and within Sydney, revealing spatial inequalities both across and among regions. Correlation and regression analysis are used to demonstrate the strength of association between computer and Internet use and other socio-economic variables. The results suggest that there is a strong class as well as spatial dimension to Australia's digital divides. Educational status and income mediate use of computers and Internet technologies, in addition to factors associated with location, indigeneity and birthplace. Such observations reinforce those made elsewhere regarding the uneven geometries of power apparent in information economies, and suggest interventions in public policy debates, particularly in the areas of telecommunications provision, resourcing of public schools, and regional economic development.     

雅布赖盆地构造演化与油气聚集

雅布赖含油气盆地位于中国西部河西走廊地区北部,处于华北克拉通阿尔善地块中南部过渡带,属北祁连构造带,中生代为走滑拉分盆地,新生代为挤压冲断坳陷盆地。燕山早期,形成东西向雅布赖拉张断陷,主控断裂为北大山正断层,沉积中心位于盆地南部;燕山中期,碰撞造山作用致使盆地北部急剧抬升,北部中-下侏罗统地层遭受强烈剥蚀;燕山晚期,阿拉善地块及其北部地区处于伸展构造环境,雅布赖山前产生东西向正断层,急剧活动,快速沉降,形成了北东向展布的新的拉张断陷盆地。喜马拉雅期,在挤压走滑作用下,雅布赖盆地南部形成北西向南倾逆冲的推覆构造,致使北大山正断层发生错断瓦解,最终形成"东隆西坳,南断北超"的挤压坳陷构造格局。雅布赖盆地主体沉积凹陷具有较强分割性,沉降凹陷分布于南部,最大沉积岩厚度为5 400 m;凹陷内侏罗系最为发育,中侏罗统新河组、青土井组暗色泥岩、煤岩为烃源岩,砂岩为储集层,新河组泥岩互层作盖层,构成盆地内最主要的含油气组合。由于雅布赖盆地特定的早期深埋,晚期抬升破坏构造格局,造就侏罗系砂岩储层早期强烈压实致密,侏罗系煤系烃源岩成熟较晚,构造发育期与烃源岩排烃期不匹配,生成油气主要表现为近源成藏与层内滞留,形成源内自生自储,致密油应是主要勘探对象。     

Displacement of the Great Divide in north Queensland associated with Neogene lava flows

In north Queensland, Australia, the ‘Great Divide’ forms the border between catchments draining into the Gulf of Carpentaria, including the Mitchell River, and those draining into the Coral Sea, including the Barron River. Until recently, it was commonly proposed that what is now the upper Barron River previously drained into the Mitchell River. However, little evidence was presented, and the assertion has been disputed. Our examination of borehole data, combined with accurate surveying of bedrock in the present Barron River channel, provides definitive evidence that paleochannels of the Mitchell River previously drained what is now the upper Barron River subcatchment. Lava that flowed down these channels at ca 1.79 Ma is evident in some of the boreholes and is exposed in the Barron River channel. The lava flows blocked the river channel, diverting the headwaters of the paleo-Mitchell River east into the Barron River, resulting in the western migration of the Great Divide. The consequent reduction in stream energy available to the truncated headwaters of Mitchell River has led to channel infill and aggradation of more than 40 m since the diversion of the Barron River. Subsurface paleochannels may be directing groundwater across the present drainage divide from the upper Barron River catchment into the Mitchell River catchment.     

Soil loss and sediment transport during the storms and landslides of May 1988 in Ruhengeri prefecture,Rwanda

In early May 1988, five prefectures in western Rwanda experienced catastrophic levels of precipitation, landslide, and flooding activity that resulted in a severe loss of life, property, and livelihood. Using data from runoff plot and hydrological monitoring stations of the Ruhengeri Resource Analysis and Management Project, the events and circumstances leading to these phenomena are reconstructed. These data show that mass wasting processes were preceded by more than 140 mm of precipitation during 4–7 May, which may have saturated local soils. A small earth tremor on 7 May, (Richter scale of 3) contributed to the onset of the catastrophic debris avalanche, torrent, and earthflow activity that commenced 24 h later. The more than 50 mm of precipitation that fell during 9 May, including a maximum 30 min intensity of 24 mm, resulted in continued surficial soil loss that averaged 34 t/ha on seven cropped, Wischmeier-type runoff plots with biological erosion control contours. The Nyamutera River, which drains the impacted area, delivered 567000 tons of suspended sediment to its mouth between 7 and 13 May. This corresponds to a basin-wide lowering of 12600 t/km², or more than half of the basin's annual suspended sediment yield. Theoretical distributions of maximum 24 h precipitation events suggest that Nyakinama and other regions in Ruhengeri are particularly prone to similar high volume events, exacerbating an already serious soil loss problem throughout the prefecture. Because contemporary land use practices directly contributed to the severity of the 1988 event, further applied research that identifies technologies capable of reducing soil loss, augmenting soil fertility, and minimizing the impacts of high magnitude and high volume rainfall is greatly needed.