Distribution of continental red paleosols and their forming mechanisms in the Late Cretaceous Yaojia Formation of the Songliao Basin, NE China     

Xuebin Du  Xinong Xie  Yongchao Lu  Jianye Ren  Shun ZhangPenglin Lang  Tao ChengMing Su  Cheng Zhang 《Cretaceous Research》2011,32(2):244-257

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甘肃新生代气候环境变化与哺乳动物群演替     

颉光普  赵得思 《第四纪研究》2011,31(4):597-607

甘肃省境内新生代沉积中富含动物化石,以早渐新世晚期、晚渐新世、早中新世早期、中中新世晚期、晚中新世、早更新世和晚更新世的哺乳动物化石最为丰富.新生代青藏高原形成、快速隆升,改变了东亚的大气环流和中国的地理格局,使甘肃的气候和地理面貌发生了巨变.甘肃省境内的哺乳动物群在这些变化背景下发生了一次次的更替.本文通过对不同时代...  相似文献   

泥石流流域岩性的坚固系数与暴发频率的关系   总被引：2，自引：0，他引：2  

鲁科  余斌  韩林  谢洪 《地球科学进展》2011,26(9):980-990

坚硬岩性地区的泥石流暴发频率较低在定性上基本可以概括岩性与泥石流暴发频率的关系,但目前还没有定量地描述岩性与泥石流暴发频率的关系。以四川省17个泥石流流域作为研究对象,通过现场调查研究泥石流形成区和堆积区粗化层颗粒的岩性、硬度以及泥石流的暴发频率,得出：①泥石流堆积区岩性组成特征基本可以代表形成区的岩性组成特征;②用地...  相似文献   

大陆下地壳麻粒岩的流变学研究进展   总被引：1，自引：0，他引：1  

李丽敏  刘祥文  谢战军 《地球科学进展》2011,26(3):275-285

大险下地壳麻粒岩的流变学研究可以解释地壳变形、壳幔物质交换以及岩石圈深部动力学过程等科学问题.前人通过研究各矿物的显微构造变形特征与变形机制,运用广义混合流变律探讨多矿物复合岩石的流变性质,结合水与流体对岩石变形强度的弱化作用,阐明在大陆下地壳变形环境下复矿麻粒岩的塑性变形和韧性流变性质.目前人们致力于对天然变形岩石和...  相似文献   

中国南方地区水系沉积物中元素丰度   总被引：6，自引：0，他引：6       下载免费PDF全文

程志中  谢学锦  潘含江  杨榕  商云涛 《地学前缘》2011,18(5):289-295

从中国南方12个省自治区230万km2面积上所采集的水系沉积物中按每1∶5万图幅一个组合样的密度组合成5 244件组合样,采用以ICP-MS、ICP-AES和XRF为主的先进的分析测试方法和严格的质量控制方法,准确测试了其中的76种元素。统计计算了中国南方地区76种元素的平均值,给出了中国南方地区水系沉积物中76种元素...  相似文献   

新疆坡十铜镍硫化物含矿岩体岩浆源区特征及构造背景探讨   总被引：7，自引：1，他引：6       下载免费PDF全文

颉炜  宋谢炎  聂晓勇  程松林 《地学前缘》2011,18(3):189-200

新疆坡北辉长岩体位于塔里木古陆东北缘的北山裂谷带中,坡一和坡十铜镍硫化物含矿超镁铁岩体位于坡北岩体内.尽管坡十超镁铁岩体与坡北辉长岩呈侵入接触,但两者的微量元素和同位素组成显示良好 的一致性,表明两岩相虽然分不同阶段侵入就位,但仍为同源岩浆的产物.MnO-TiO2-R2O5及Th-Hf-Ta判别图解显示坡北及坡十岩体的...  相似文献   

Mechanism of cultivation soil degradation in rocky desertification areas under dry/wet cycles     

Wei-min Ye  Zi-yuan Qi  Bao Chen  Ji Xie  Yu Huang  Yao-ru Lu  Yu-Jun Cui 《Environmental Earth Sciences》2011,64(1):269-276

Karst rocky desertification is a process of land degradation involving serious soil erosion, extensive exposure of basement rocks. It leads to drastic decrease in soil productivity and formation of a desert-like landscape. In this regard, changes in climatic conditions are the main origin of the soils degradation. Indeed, soils subjected to successive dry/wet cycling processes caused by climate change develop swelling and shrinkage deformations which can modify their water retention properties, thus inducing the degradation of soil–water capacity. The ecological characteristics of cultivation soils in karst areas, Southwest of China, are extremely easy to be affected by external environmental factors due to its shallow bedding and low vegetation coverage. Based on the analysis of the climate (precipitation) of this region during the past decades, an experimental study has been conducted on a cultivated soil obtained from the typical karst area in southwestern China. Firstly, the soil–water properties have been investigated. The measured soil–water retention curve shows that the air-entry value of the soil is between 50 and 60 kPa, while the residual saturation is about 12%. Based on the experimental results, three identifiable stages of de-saturation have been defined. Secondly, a special apparatus was developed to investigate the volume change behavior of the soil with controlled suction cycles. The vapor equilibrium technique was used for the suction control. The obtained results show that under the effect of dry/wet cycles, (1) the void ratio of the cultivated soil is continuously decreasing, leading to a gradual soil compaction. (2) The permeability decreases, giving rise to a deterioration of water transfer ability as well as a deterioration of soil–water retention capacity. It is then obvious that the long-term dry/wet cycling process caused by the climate change induce a continuously compaction and degradation of the cultivated soil in karst rocky desertification areas.  相似文献   

Microbial community changes in contaminated soils in response to phenanthrene amendment   总被引：4，自引：1，他引：3  

S. Y. Zhang  Q. F. Wang  S. G. Xie Ph.D. 《International Journal of Environmental Science and Technology》2011,8(2):321-330

Leachate and reclaimed wastewater have become the important sources of polycyclic aromatic hydrocarbons in soils. However, the information on bioremediation of leachate and reclaimed wastewater-contaminated soils is still lacking. Identification of changes in microbial structure or of enriched genera related to biodegradation could aid identification of particular organisms or consortia capable of degrading polycyclic aromatic hydrocarbons in these contaminated soils. In this study, terminal restriction fragment length polymorphism, coupled with 16S Ribosomal ribonucleic acid clone library analysis, was applied to investigate the composition of bacterial community in leachate-contaminated soil or grassland soil irrigated reclaimed wastewater and the response to phenanthrene amendment. Results showed that phenanthrene amendment had significant but different impacts on microbial community structure, dependent on soil source. Several greatly enriched terminal restriction fragments with phenanthrene biodegradation were identified. Moreover, genus rhizobacteria, possibly linked to phenanthrene biodegradation, was firstly reported in this study. This work might provide some new insights into bioremediation of polycyclic aromatic hydrocarbons-contaminated soils.  相似文献   

裂隙岩体宏观力学参数的二维数值模拟   总被引：1，自引：0，他引：1  

谢云跃 《地质与勘探》2015,51(2):376-382

岩体通常含许多不同尺度的裂隙,因而力学性质非常复杂。由于现场测试及常规实验室试验常受各种条件的限制,因而其不能准确反映岩体的宏观物理力学性质。本文基于有限元分析软件对二维情况下的完整岩体和含不同倾角的软弱夹层的岩体在单轴和双轴压缩下进行了数值模拟,得到岩体变形的应力-应变曲线。该类曲线能反映裂隙对岩体力学参数的影响,对于指导工程实践有一定的意义,并且为获取岩体力学参数提供了新的途径。  相似文献   

Monitoring the land subsidence with persistent scatterer interferometry in Nansha District,Guangdong, China   总被引：1，自引：1，他引：0  

Minsi Ao  Changcheng Wang  Rongan Xie  Xingqing Zhang  Jun Hu  Yanan Du  Zhiwei Li  Jianjun Zhu  Wujiao Dai  Cuilin Kuang 《Natural Hazards》2015,75(3):2947-2964

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