近40年天山冰川变化的遥感监测   总被引：3，自引：0，他引：3  

李宝林  张一驰  周成虎 《地理学报(英文版)》2004,14(3):296-302

Both marginal fluctuation and areal change were used to detect the accurate dynamics of glacier change in the study area using Landsat MSS, ETM, SPOT HRV and topographic maps based on GIS. From 1963 to 1977, four of eight glaciers advanced, two of them retreated and another two kept stable, the glacier advanced generally. From 1977 to 1986, four of eight glaciers retreated and the others kept stable, but the retreated glaciers were those which advanced from 1963 to 1977. From 1986 to 2000, seven of eight glaciers retreated and only one glacier kept stable, the retreating velocity was 10-15 m/a. Glacier recession in this period became very fast and universal. From 1963 to 2000, the area of glaciers decreased from 5479.0 ha to 4795.4 ha, up to 12.5%. It is alarming that most of glacier retreats happened from 1986 to 2000. This was very consistent with change process of summer mean temperature in this region and global warming beginning in the 1980s.  相似文献   

陕南秦巴山区植被生态功能的价值测评   总被引：61，自引：1，他引：60  

任志远  李晶 《地理学报》2003,58(4):503-511

根据秦巴山区20世纪末植被类型及覆盖度的分布,在GIS支持下测定秦巴山区植被生产和生态调节的物质量。利用生态经济学方法,测定各类植被生态功能的价值,建立秦巴山区植被生态数据库及植被生态账户。生态服务功能价值测评中,充分考虑了不同类型的覆盖度差异,并结合能量平衡、水量平衡和区域蒸散模式,测评结果表明：陕南秦巴山区植被生态系统有机质生产价值为199.6×108 元/a;植被保持土壤经济价值为22.64×108元/a;植被涵养水源的经济价值为22.66×108 元/a;植被固定CO2价值为352.24×108元/a;释放O₂价值为374.19×108 元/a;陕南秦巴山区植被有机物生产、保持土壤、涵养水源、固定CO₂和释放O₂ 5种生态服务功能价值共968.33×108 元/a。其中温带落叶阔叶林贡献率最高占29.35%,亚热带竹林、亚高山灌丛、草甸草原、山麓果树生态服务价值比重均在1%以下。  相似文献   

TECTONIC EVOLUTION OF THE YANGTZE PASSIVE MARGIN AND SONGPAN GARZ? FOLD BELT, CHINA     

Mathew J. Harrowfield  Christopher J.L. Wilson WT  ”BX 《地学前缘》2000,(Z1)

TECTONIC EVOLUTION OF THE YANGTZE PASSIVE MARGIN AND SONGPAN GARZ? FOLD BELT, CHINA  相似文献   

RECORD OF BLOCK ROTATION AND MAGNETIC FIELD REVERSALS IN THE TETHYAN HIMALAYA (HIDDEN VALLEY, CENTRAL NEPAL)     

C. Crouzet  H. Stang  E. Schill  E. AppelWT  ”BX 《地学前缘》2000,(Z1)

RECORD OF BLOCK ROTATION AND MAGNETIC FIELD REVERSALS IN THE TETHYAN HIMALAYA (HIDDEN VALLEY, CENTRAL NEPAL)  相似文献   

THE EVOLUTIONARY HISTORY OF THE WEST KUNLUN MOUNTAINS: A TECTONIC RECONSTRUCTION BASED ON STUDIES OF MAGMATISM     

Yuan Chao    Sun Min  Li Jiliang WT  ”BX 《地学前缘》2000,(Z1)

THE EVOLUTIONARY HISTORY OF THE WEST KUNLUN MOUNTAINS: A TECTONIC RECONSTRUCTION BASED ON STUDIES OF MAGMATISM  相似文献   

NORTH QAIDAM ULTRAHIGH PRESSURE METAMORPHIC (UHPM) BELT ON THE NORTHEASTERN QINGHAI-TIBET PLATEAU AND ITS EASTWARD EXTENSION     

Yang Jingsui  Song Suguang  Wu Cailai  Shi Rendeng  Marc Jalivet 《地学前缘》2000,(Z1)

NORTH QAIDAM ULTRAHIGH PRESSURE METAMORPHIC (UHPM) BELT ON THE NORTHEASTERN QINGHAI-TIBET PLATEAU AND ITS EASTWARD EXTENSION1　YangJS ,XuZQ ,LiHB ,etal.DiscoveryofeclogiteatnorthernmarginofQaidambasin ,NWChina[J] .ChineseScienceBulletin,1998,4 3:1755～ 176 0 . 2　ZhangJX ,ZhangZM ,XuZQ ,etal.TheagesofU PbandSm NdforeclogitefromthewesternsegmentofAltynTaghtectonicbelt—theevidencesforexistenceofCaledonianorogenicroot[J] .ChineseScienc…  相似文献   

Chemical Weathering in the Batura Glacier Basin, Karakoram Mountains     

Wang Ninglian  Yao Tandong  Fu Zongtang  Yang Zhiqiang WT  ”BX 《地学前缘》2000,(Z1)

CHEMICAL WEATHERING IN THE BATURA GLACIER BASIN, KARAKORAM MOUNTAINStheChineseNationalBasicResearchProgramme(GrantG 19980 4 0 80 0 )andChineseNationalScienceFoundation (NSFgrant 4 980 10 0 4 )  相似文献   

陕甘宁盆地中部马五段上部成岩层序地层学研究及其意义   总被引：8，自引：0，他引：8  

周劲松  赵澄林  刘明梅 《岩石矿物学杂志》2000,19(2):113-120

陕甘宁盆地具有较有利的成岩层序地层学研究条件。根据多种资料,将盆地中部马五段上部划分出八个准层序。准层序内部的酸不溶物含量、自然伽玛、曲线、稳定碳同位素值及残余含盐量等参数呈现规律性变化,这为相似类型的地层的准层序划分提供了新的方法。在不同的成岩作用中,准层序上站的溶解作用／去膏化作用明显强于准层序下部;准层序上部多为准同生白云岩化形成的泥－粉晶白云岩,下部则多为再次云化形成的细粉晶－粗粉白云岩,  相似文献   

Petrographic and SHRIMP Studies of Zircons fromthe Caledonian Xiongdian Eclogite, NorthwesternDabie Mountains   总被引：2，自引：0，他引：2  

I.S.WILLIAMS 《《地质学报》英文版》2000,74(4):766-773

The Xiongdian eclogite occurring in the Sujiahe tectonic melange zone at Luoshan County, Henan Province, in the western Dabie Mountains, is typical high-pressure (HP)-ultrahigh-pressure (UHP) and medium-temperature eclogite. The occurrence, internal texture and surface characteristics of zircons in eclogite were studied rather systematically petrographically combined with the cathodoluminescence (CL) and scanning electron microscope (SEM) methods. Zircons are mainly hosted in garnet and other metamorphic minerals with sharp boundaries, have a multifaceted morphology and are homogeneous or exhibit a metamorphic growth texture in the interior, thus indicating that they are the product of metamorphism. SHRIMP analyses give zircon 206Pb/238U ages of 335 to 424 Ma and show a certain degree of radiogenic Pb loss; therefore it may be inferred that the age of 424? Ma represents the minimum age of a HP-UHP metamorphic age. From the above analyses coupled with previous Sm-Nd, 40Ar-39Ar, U-Pb and 207Pb/206Pb age d  相似文献   

U-Pb Zircon Dating of the Yeniutan Granitic Intrusion in the Western Sector of the North Qilian Mountains   总被引：1，自引：0，他引：1  

MAO Jingwen  ZHANG Zuoheng  JIAN Ping  WANG Zhiliang  YANG Jianmin  ZHANG Zhaochong Institute of Mineral Resources  Chinese Academy of Geological Sciences  Beijing Institute of Geology  Chinese Academy of Geological Sciences  Beijing 《《地质学报》英文版》2000,74(4):781-785

Zircons from granodiorite and biotite granite in the Yeniutan granitic intrusion in the western North Qilian Mountains yielded a weighted mean 206Pb/238U apparent age of 460±3 Ma, suggesting that the intrusion originated during the late stage of plate subduction. Its related Ta'ergou and Xiaoliugou deposits are two of the few large tungsten deposits formed in the plate subduction environment in the world. The U-Pb dating of the zircons from the biotite granite gave a discordant lower intercept age of 183±4 Ma, which implies that the Yanshanian event was probably superimposed on the North Qilian region.  相似文献