Spatial pattern of rural settlements in the upper reaches of the Minjiang River

A quantitative analysis of the spatial pattern of rural settlements in the upper reaches of the Minjiang River was made with the major data sources being the relevant ETM image and the national geographical database of China (including contour line, river and road) at the scale of 1:250 000, and using image interpretation and field investigation to obtain spatial information on rural settlements. The results of the spatial analysis technique of GIS and correlation analysis showed that most settlements (78.2 %) were located in the mountain area at 1500 ∼ 2700 m altitude, and almost half in the arid valley area. More than 80.0 % of settlements had their slopes above 15°. Most settlements had good access to water resources, roads and communications, and tended to cluster close to the road network rather than the river. About half of the rural settlements in the study area were relatively concentrated, while the others were decentralized. Those with higher altitude usually had land with steep slope, inconvenient water and road accesses, and were located far apart from each other. In view of such a situation, further research should be done to make reasonable countermeasures on these settlements for better living conditions and ecosystem stability.     

宁南县城后山泥石流综合治理工程财务管理

宁南县城后山泥石流综合治理工程总预算为159.00万元,实际拨款129.01万元。为用好这笔资金,严格了财务管理制度,采取了专项资金专人管理措施,加强对用工、材料、资金和施工等的管理,使工程不但超计划数量完成,而且未追加投资,做到了费省效宏,较好地发挥了投资效益。     

Land use change and its ecological effect in Qian'an County of Jilin Province

Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian'an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors.　(3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening of landscape suitability.     

大别山岳西县石关混合岩锆石SHRIMP定年及其地质意义

安徽岳西县石关混合岩属于原北大别变质杂岩的一部分。锆石SHRIMPU-Pb定年结果:第一次变质时间为232Ma,相当于晚三叠世早期,第二次变质时间为207Ma,相当于晚三叠世晚期。复合锆石的核部(继承锆石)为发育韵律环带的岩浆碎屑锆石,其年龄值分别为560Ma、444Ma、394Ma、378Ma和331Ma,暗示其原岩非岩浆岩,而应为沉积岩;研究结果还表明,北大别石关混合岩经历了两次变质作用:①超高压变质作用,变质时间为232Ma(n=5加权平均年龄);②退变质作用,时间为207Ma。与苏鲁地区超高压变质和退变质时间一致。     

福建永安丰门坑多金属矿地质特征及找矿前景

永安丰门坑多金属矿呈似层状、层状、透镜状,贮存在寒武系林田组下段钙质碎屑岩中,矿床具明显的层控和热液叠加改造特征,为沉积-热液改造型多金属矿床。该多金属矿床的发现,为我省在寒武系林田组中寻找该类矿床提供新的目标。     

武山温泉地热资源状况及开发利用前景分析

武山温泉热流体主要赋存于F1、F2断裂交汇部位的碎裂状斑状花岗岩体中,热水水温56.2℃,富含锂、锶、氟、偏硅酸等多种微量元素,主要用于浴疗治病和保健。本文通过对温泉地热资源形成的地质背景分析,初步论证了地热田的热储和控热构造,评价了地热资源储量,并对温泉开发利用前景作了分析。     

镇赉县土地利用结构调整

基于遥感与GIS进行吉林省镇赉县土地利用现状调查与生态适宜性评价, 通过分析二者差异提出土地利用调整方向及对策, 进一步优化土地利用结构。研究结果显示, 镇赉县宜林地和宜牧地的利用现状主要是盐碱地, 其次为耕地, 很少用于林地与草地; 宜农地和宜农、林、牧地利用格局单一, 耕林草比例不合理; 土地利用结构调整方向为盐碱地治理、退耕还林还草与土地利用格局优化。结合自然环境特点分析, 调整后的土地利用模式有农林复合、林草复合及开发水田等3种, 农、林、牧用地比例接近3∶1∶1, 空间格局交替安排。     

藏北日土县拉竹龙地区志留系

根据在西藏西北部日土县拉竹龙地区重新测量了西藏区调大队1984年所测的两个地层剖面——饮水河北岸剖面和兽形湖北岸剖面,在原来定为上奥陶统兽形湖组的底部发现了一套含笔石和几丁石化石的黑色页岩和炭质板岩,其中笔石Pristiograptus和几丁石Ancyrochitina brevicollis、Conochitina sp.为志留系兰多维列统Tely-chian阶的标准分子。同时在兽形湖组中也发现了大量兰多维列世的腕足类化石Hindella xizangensis和竹节石Gotlandellites sp.。证明了拉竹龙地区饮水河北岸和兽形湖北岸两个剖面均未出现真正的奥陶纪地层。通过所采集到的笔石、几丁石、腕足类、三叶虫、头足类、牙形刺、竹节石、珊瑚、遗迹化石的准确鉴定,重新修订了本地区志留系的划分和地层序列:自下而上依次为以笔石相为代表的兰多维列统饮水河组,以碎屑岩相为代表的兰多维列统兽形湖组,以碳酸盐沉积为主的文洛克统普尔错组和以碳酸盐岩相为主的罗德洛统至普里道利统野牛坡组。本区志留系目前发现的最低层位相当于兰多维列统Telychian阶的笔石带Spirograptusturriculatus带和Streptograptus crispus带,最高层位相当于欧洲和藏南壳相志留系的最高一个头足类化石带Kopaninoceras juncudum带或牙形刺组合Neoprioniodus latidentatus-Ligonodina siluria组合。     

河南嵩县地区石英斑岩地质与地球化学特征研究

河南嵩县位于豫西熊耳山地区,区域内金矿床分布众多,发育地层以太古界太华群和中元古界熊耳群为主,岩石变质较深,构造变动强烈,岩浆活动频繁,燕山期大量中酸性岩浆侵入伴生了大量典型的小斑岩体,如石英斑岩。本文通过对研究区内石英斑岩的野外地质观察和室内化学分析研究认为:①石英斑岩相对于区内燕山期花岗岩体更偏酸性,TiO2、P2O5、MnO平均含量相对于区内燕山期花岗岩偏低;岩石富碱富钾质,属于钙碱性岩石系列,分离结晶作用进行的比较彻底,岩体形成时的氧逸度较高;据CIPW计算石英斑岩标准矿物主要矿物为石英、钠长石、钙长石、正长石,副矿物为透辉石、刚玉、紫苏辉石、钛铁矿、磁铁矿、磷辉石等,刚玉含量普遍相对较高;②石英斑岩Au含量相对于区域内太华群和熊耳群地层,以及区内五丈山、花山、合峪三大花岗岩体Au含量大大富集;与原始地幔相比具有强烈富集强不相容元素、弱不相容元素富集相对较弱;③雷门沟石英斑岩与区域内花山岩体各稀土元素含量及稀土元素各类特征参数非常接近,其它地区石英斑岩稀土总量较低,轻重稀土分馏不是很明显,除店房矿区的石英斑岩具有较明显的Eu正异常外,其它地区基本无Eu和Ce异常。     

若尔盖县大骨节病分布特征及其与地质环境的关系

大骨节病是一种地方性、变形性骨关节病。国内外学者历经160年的研究,病因假说上百种,但至今仍无定论。若尔盖县是中国大骨节病发病率较高的病区之一,通过在病区开展野外调查、岩土水样测试等工作,本文总结了该区大骨节病分布特征和自然与地质环境特征,探讨了大骨节病分布与地层岩性、土壤、地形地貌、饮水水源等地质环境的关系。研究表明:基岩岩性及其土壤母质成分是影响病情分布的基本因素;病区土壤中Se、Mo、Ba等元素含量较非病区低,N、P、Pb、S元素含量高于非病区;饮用地表水中的矿化度、硬度、腐殖酸含量病区与非病区差异不显著,病区硒含量低于轻、非病区;大骨节病的致病影响因素复杂,除与岩、土、水地球化学环境因素有关外,亦与饮食结构等因素有关;大骨节病与地质环境关系密切,其病因需进一步探索。