简介:Evidenceforamantleand/orbasalticcomponentinKTboundarydistalejectaisapparentlyinconsistentwithejectionfromChicxulubCratersinceitislocatedon~35kmthickcontinentalcrust(DePaoloetal.,1983;Montanarietal.,1983;HildebrandandBoynton,1988,1990).Evidenceformafic/ultramafictargetrockswasreinforcedbydiscoveryofchromites,somewithshockplanardeformationfeatures(PDF),inimpactlayersamplesfromsitesinsouthernColoradoandeasternWyoming(Bohoretal.,1990).However,untilnowitwasunclearwhetherthechromitesoriginatedwithanimpactororwithterrestrialtargetrocks.Tothisend,high-precision54Cr/52CrisotoperatiosweremeasuredonKTboundarychromitesalongwithknownterrestrialchromites.Wefindaterrestrial54Cr/52CrratioinKTboundarychromitesfromimpactlayersamplescollectedattheabovesitesoverthelastseveralyears(Fig.1).Ejectedterrestrialchromitessuggesttheimpactsampledterrestrialmaficand/orultramafictargetrocksnotknowntoexistintheChicxulubtargetarea.
简介:RamanpeaksofvarioushydratesintheH2O-NaCl-CaCl2systemhavebeenpreviouslyidentified,butaquantitativerelationshipbetweentheRamanpeaksandXNaCl(i.e.,NaCl/(NaCl+CaCl2))hasnotbeenestablished,mainlyduetothedifficultytofreezethesolutions.Thisproblemwassolvedbyaddingaluminapowdertothesolutionstofacilitatenucleationofcrystals.Cryogenic(-185oC)Ramanspectroscopicstudiesofalumina-spicedsolutionsindicatethatXNaClislinearlycorrelatedwiththetotalpeakareafractionofhydrohalite.Capsulesofsolutionsmadefromsilicacapillarywerepreparedtosimulatefluidinclusions.Mostoftheseartificialfluidinclusionscouldnotbetotallyfrozenevenattemperaturesaslowas-185oC,andthetotalpeakareafractionofhydrohaliteisnotcorrelatedlinearlywithXNaCl.However,thedegreeofdeviation(?XNaCl)fromthelinearcorrelationestablishedearlierisrelatedtotheamountofresidualsolution,whichisreflectedbytheratio(r)ofthebaseline"bump"area,resultingfromtheinterstitialunfrozenbrinenear3435cm-1,andthetotalhydratepeakareabetween3350and3600cm-1.Alinearcorrelationbetween?XNaClandrisestablishedtoestimateXNaClfromcryogenicRamanspectroscopicanalysisforfluidinclusions.
简介:M7.0Lushan地震触发了的s山崩的一个巨大的数字。印射的山崩危险性是很重要的。证据(悲痛)和逻辑回归(LR)的重量方法广泛地为LSM(印射的山崩危险性)被使用了。然而,限制仍然存在。悲痛能够估计每个因素的不同的班的影响,但是忽视在因素之间的关联。当它不能够评估不同的班的影响时,LR能在因素之中分析关系。这份报纸为LSM建议LR和悲痛的一个联合方法,利用他们的单个优点并且克服他们的限制。1289山崩的库存被使用:70%为为确认训练并且留下是选择随机的。11个山崩条件因素在模型被采用,结果用操作特征(巨鸟)曲线的接收装置被验证。结果证明LR悲痛模型比LR模型有更好的精确性,生产在有0.802成功的价值的曲线下面的一个区域并且0.791预兆,比LR模型的高(0.715成功并且0.722预兆)。悲痛和LR的联合方法能为印射的导致地震的山崩危险性提供精确性的有希望的水平,这因此被结束。
简介:五河朱顶金矿产于太古代绿岩带中,是多种成矿作用叠加、改造的综合产物属中低温热液充填-交代型金矿床。成矿物质主要来自岩浆分异热液,其次来自围岩和中本性脉岩。朱顶-石门山左行旋扭韧-脆性剪切带是主要的导矿构造,其次级NNE向断裂破碎带是主要的容矿场所。
简介:马石铜矿床位于安庆-贵池矿集区内,是一个几经上下、近年找矿有较大突破的中型斑岩矿床。矿体赋存于花岗闪长斑岩体顶部及侵入接触带附近。矿床主矿体2个,编号为Ⅲ、Ⅳ。矿体呈不规则的透镜状产出,其形态、产状受岩体及接触带构造控制,走向北东,倾向北西,倾角9°~33°。矿石矿物主要为黄铜矿,其次为黄铁矿、辉钼矿、黝铜矿、白铁矿、闪锌矿、方铅矿、胶状黄铁矿等。脉石矿物主要有中—更长石、钾长石、石英等。矿石结构主要有自形—半自形晶、他形晶、乳滴状、压碎—碎斑、交代溶融结构等,矿石构造主要有脉状—网脉状、浸染状、角砾状、胶结、次块状构造等。矿体围岩蚀变有青磐岩化、泥化带、石英—绢云母化、钾质蚀变带,铜矿化与泥化带、石英—绢云母化蚀变带关系最为密切,表现为矿体中石英脉、石膏脉、钾化等很发育。矿床成因类型是斑岩型铜矿床,主要控矿因素是构造、岩浆岩。