简介：KarstrocksfromtheHuanglongFormationexposedatthemarginoftheEasternSichuanBasincanbedividedintofourtypes:slightlycorroded,moderatelycorrodedporous,intenselycorrodedbrecciatedandintenselycorrodedandreplacedsecondarycalcickarsticrocks.Thecarbon,oxygenandstrontiumisotopecompositionsofthevariouskarstrocksareanalyzedsystematicallyandcomparedtorockswithoutkarstcorrosion.Theresultsindicatethat(1)theHuanglongFormationintheeasternSichuanBasinwasarestrictedbaysuppliedandcontrolledbyfreshwaterinwhichmudmicriteandmud-dolomicriteexhibitlowδ13Candδ18Ovaluesandhigh87Sr/86Srratios;(2)alltypesofkarsticrocksinthepaleokarstreservoirsoftheHuanglongFormationintheresearchareaareaffectedbyatmosphericfreshwaterwiththeδ13Candδ18Ovaluesand87Sr/86Srratiosintheoriginalformationapproachingthoseofatmosphericfreshwater,whichreflectsancienthydrologicalconditions,fluidproperties,isotopicsourceandthefractionationeffect;(3)theintenselycorrodedandreplacedsecondarylimestoneisaffectedbyavarietyofdiageneticfluids,oftenreflectedbyδ13Candδ18Ovalues,whilethe87Sr/86Srratiosexhibitthestrongdegreeofthecorrosion;(4)aftercomparingthe87Sr/86Srratiosofeachtypeofkarstrock,thediageneticfluidsaredeterminedtobemainlyatmosphericfreshwater,anddependingonthestrengthofcorrosion,andthelow87Sr/86Srratiofluidsinthelayerwillparticipateinthekarstprocess.Thecarbon,oxygen,andstrontiumisotopesofdifferentkarsticreservoirscanprovidemeaningfulgeochemicalinformationforforecastingandevaluatingthedevelopmentanddistributionrulesoftheHuanglongFormationatthemarginoftheeasternSichuanBasinintimeandspace.更多还原

简介：

简介：AccordingtoVeningMeinesz-Moritz(VMM)globalinverseisostaticproblem,eithertheMohodensitycontrast(crust-mantledensitycontrast)ortheMohogeometrycanbeestimatedbysolvinganon-linearFredholmintegralequationofthefirstkind.HeresolutionstothetwoMohoparametersarepresentedbycombiningtheglobalgeopotentialmodel(GOCO-03S),topography(DTM2006)andaseismiccrustmodel,thelatterbeingtherecentdigitalglobalcrustalmodel(CRUST1.0)witharesolutionof1o×1o.ThenumericalresultsshowthattheestimatedMohodensitycontrastvariesfrom21to637kg/m3,withaglobalaverageof321kg/m3,andtheestimatedMohodepthvariesfrom6to86kmwithaglobalaverageof24km.ComparingtheMohodensitycontrastsestimatedusingourleastsquaresmethodandthosederivedbytheCRUST1.0,CRUST2.0,andPREMmodelsshowsthatourestimateagreesfairlywellwithCRUST1.0modelandratherpoorwithothermodels.TheestimatedMohodepthsbyourleast-squaresmethodandtheCRUST1.0modelagreeto4.8kminRMSandwiththeGEMMA1.0basedmodelto6.3km.

简介：淮南矿务局潘三矿自建井以来共发生十多次煤及瓦斯突出，给煤矿生产造成严重危害，通过对典型实例的描述、结合矿井地质资料的分析，认为媒矿及瓦斯突出与矿区的地质构造带有直接的关系，且分布范围局限，建议对地质构造应力较为集中的地带进行监控、分析、预测。

简介：在华南的Dajiangbian形成是统治siliciclastic的沉积继任，低档变态在卡赛西亚·布洛克的西方的边缘上扔了，并且被glaciogenicdiamictite(Sizhoushan形成)盖住。Sizhoushanglaciogenic阶层能被归因于Jiangkou冰川(Sturtian冰川)他们在华南与Jiangkou阶层分享stratigraphic和lithological类似的事件。在整个Dajiangbian形成的上面的部分的一些碳酸盐，燧石和页岩单位为碳酸盐碳同位素被取样(13Ccarb)和器官的碳同位素(13Corg)分析。geochemical的一个范围索引包括氧同位素(18O)并且Mn/Sr(Fe/Sr)比率建议主要的碳同位素价值在上面的Dajiangbian形成被保存。上面的Dajiangbian形成表演13C向上减少向的-0.1,的carb到-5.4。我们建议否定13在Sizhoushandiamictite下面的C旅行是有Pre-SturtianIslay13Ccarb异例并且与全球Neoproterozoic同位素地层学允许关联。我们发现碳酸盐和上面的Dajiangbian形成的器官的碳同位素数据被联合，与13Ccarb-13C在多重大陆上观察的org模式。

简介：<正>1IntroductionTheundergroundbrineresourcesdistributingwidelyinSichuanBasin,Chinahavedrawnworldwideattentionduetotheirunusualelementabundanceandexcellentquality.

简介：本报讯近日，地震预警四川省重点实验室传出消息，首都圈地震预警系统经过近一年半的建设，目前已建成并投入运行，将为首都圈民众和地铁、化工等重大工程提供地震预警服务。