简介：~~

简介：Thisstudyisthefirsttoreporttheradiocarbonages,mineralogical,morphological,geochemicalandstableisotopecompositionsofcalcretesfromNeogenesedimentsaroundlakesEymirandMoganintheG?lba??BasinofCentralAnatolia.MorphologicallydifferentformsofcalcretesintheG?lba??Basinincludepowdery,nodular,fractureinfill,laminarandhardpantypes.Calciteisthedominantmineralofcalcretecompositions;thediagnosticfeaturesofdessicationcracks,randomfractures,MnOliningsanddensespariticinfillingsareobserved.Chemicalanalysesshowaridconditionswithmeanannualprecipitationof<50mm.δ13Ccompositionsofthecalcretesrangefrom-6.77‰to-9.32‰PDB,typicalformostpedogeniccalcretes,reflectingthedevelopmentunderseasonallyaridclimatesandC3-dominatedvegetationcover.δ18Ovaluesarebetween-5.57‰and-7.80‰PDB,indicatingtheformationfrommeteoricwaterinavadosezoneenvironment.TheresultssuggestthattheMiddlePleistocenewasariderandwarmer,favouringtheformationofpalygorskiteinassociationwiththedifferentformsofcalcreteoccurrences,whereastheLatePleistocenewasdryerandcooler,supportingthedevelopmentofcalcretes.

简介：

简介：瞬变电磁法（TEM）是近年来国内外发展速度较快、应用效果较好的一种电磁方法，由于其施工便利、成本低廉、工作效率高、应用效果明显等优点，已广泛应用于金属、煤炭、地下水等矿藏勘查．该方法应用于地震勘探中的表层结构调查，虽不能直接得到近地表地质体岩性信息．但可通过连续观测获取不同岩性间电性差异信息，根据电性相对关系得到准确的近地表地质体形态和岩性分布规律，为地震资料后续处理提供可靠的静校正量．瞬变电磁法勘探深度由浅层5m到中深层300m左右．准噶尔盆地南缘东部台28井区勘探实例表明，通过电性分层、小折射和地震微测井成果资料综合解释，在表层结构建模和计算静校正量方面取得良好效果．

简介：