学科分类
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9 个结果
  • 简介:重要信息指差错运动(例如,差错活动时期,紧张,频率,和甚至有活力的背景)当渗出或磨擦时,能被解决差错凿揭示,它是差错运动的结果。地调查包含了样品从QinlingOrogenic带(QOB)的西方的片断的Bailong河差错系统收集;差错凿的44件样品为石英被收集微形态学的分析。这些样品用扫描电子显微镜学的地排放被分析。另外,14件样品为标明日期的热照明被测试。结果证明大多数石英谷物的表面质地被鱼规模,像苔藓的质地,和钟乳石描绘。然而,像皮的破裂和worm-hole-like塑造了的橘子的小数量表面质地被观察。而且,在石英谷物的一些典型conchoids或subconchoidal破裂能被看见。这暗示Bailong河差错在第四级的时期期间反复是活跃的,但是主要运动时期是更新世。标明日期价值的14热照明显示出二个年龄组:343.29-184.06ka和92.18-13.87ka。这些学习数据表明那个差错运动在上新世期间开始了,在更新世的早中间的时期经常发生了,并且运动的山峰频率在早更新世被到达。差错运动被停止在早Holocene终止了。结果为在QOB的西方的片断的自然灾难风险评估是重要的。

  • 标签: 石英颗粒 表面纹理 白龙江 故障 断裂活动 场发射扫描电子显微镜
  • 简介:Al-richmetapelitesfromtheMashankhondaliteseriesarecharacterizedbytheassemblageSpl+Grt+Sil+Crd+Bt+Pl(An72)+Kfs+Quartz+graphite.Largeamountsofspinel+quartzassemblagesoccurasinclusionsingarnetandprismaticsillimaniteintheAl-richmetapelitesoftheMashancomplex,NEChina.ThechemicalcompositionofspinelischaracterizedbyZn-rich(XZn=0.33–0.40.XZn=Zn/Zn+Mg+Fe*)(Fe*=Fe2++Fe3+)andFe3+rich(upto0.31p.f.u.).ThecharacteristicchemicalcompositionandthemineralassociationindicatedthattheformationofspinelandquartzassemblagemaybeduetothebreakdownofZn-richstaurolite.ThegeothermobarometersstudiesshowthatthepeaktemperatureoftheMashancomplexisaround820℃andthepeakpressuresis8.0kbar.TheMashancomplexshowsatypicalorogenstyleP-Tpath.

  • 标签: 孔兹岩系 尖晶石 石英石 泥质岩 Zn 东北
  • 简介:<正>PRELIMINARYSTUDYONTHEORE-FORMINGCONDITIONSOFTHEAu-Pb-QUARTZVEINTYPEOREDEPOSIT,CHINAHeZhili,XuJiuhua,YangZhenlinandDuJafeng(Dept.ofGeol.,Univ.ofScie.andTech.Beijing,100083Beijing,China)Ore-formingcondition,Au-Pb-quartzvein,oredeposit,ChinaTherearefewAu-Pb-QuartzveintypeoredepositsinothercountriesexceptChina.Itmightberelatedtothegeohistoryandgeotectonicbackground.However,thiskindoforedeposithasanimportanteconomicalsignificanceinChina.Itsformationisduetothedis-tinctivegeologicalconditionsofchina.WendongAu-Pb-QuartztypeoredepositincludingWenyuandDongchuanginXiaoqinlinggoldfieldisthemosttypical.Itisapolygeneticandcompoundoredeposit,JintongchaandotherdepositslyingtothewestofitinXiaoqinlingareaareAu-Pb-Quartzveintypeoredeposits.OthersofthisarealyingtotheeastofJintongchaareAu-Quartzveintype.Thisphenomenonstemsfromthezonnaldistributionofminernalde-positsa

  • 标签: ORE-FORMING condition Au-Pb-quartz VEIN ORE deposit
  • 简介:TheYangshangolddepositisasuper-largefine-graineddisseminatedgolddepositlocatedinsouthernGansuProvince.ItsmetallogenicagehasbeendeterminedbyusingthecathodoluminescenceimageandionprobeU-Pbdatingtechniques.Itisfoundthatzirconsfromquartzveinletofthefine-graineddisseminatedgoldoreshowcharactersofmagmaticoriginwithprismidiomorphism,oscillatoryzoninganddominantTh/Uratiosof0.5-1.5.Threemainpopulationsofzirconsareobtained,givingaverage206pb/238Uagesof197.6±1.7Ma,126.9±3.2Maand51.2±l.3Marespectively.ThefirstagecorrespondstotheK-Arageoftheplagiogranitedike,whilethelattertwoagesindicatethatburiedCretaceousandTertiaryintrusivesexistintheorefield,suggestingthattheYangshangolddepositwasgeneticallyrelatedtothethreemagmatichydrothermalactivities.Bycontrast,zirconsfromcoarsegold-bearingquartzveinintheminingareaaremucholderthanthehostrock,indicatingthattheveinwasformedearlierandwasnotcontaminatedbylatermagmaticfluids.ItisconcludedthatthecouplingofmultiperiodichydrothermalactivitiesintheminingareahascontributedalottomineralizationoftheYangshangolddeposit.

  • 标签: 散布型金矿 石英矿脉 SHRIMP 甘肃 阴极发光图像
  • 简介:在Quanji山岳的变形早Paleoproterozoicgranitoids,西北的中国为在TarimCraton和诺思中国Craton之间的关系提供限制。在granitoids底盘之中,Mohe石英闪长岩的岩石典型地显示出adakiticgeochemical特征,与中等K2O/Na2O比率(0.561.17)和高Sr(519619ppm)低Y(9.3720.40ppm)和Yb(0.971.77ppm)集中。岩石有在+2.4和+4.4和2.432.59Ga的弄空的披风Nd模型年龄之间的Nd(t)价值。magmatic锆石有积极Hf(t)价值从+0.40到+7.60和2.432.70Ga的弄空的披风Hf模型年龄,与在2.54和2.65Ga的主要山峰。geochemical和Nd-Hf同位素的特征显示Mohequartz-dioritic岩石可能被高压的变形少年的部分融化形成在在早Paleoproterozoic的post-orogenicextensional政体的外壳的岩石。它建议重要外壳的生长在2.4和2.52.7Ga发生在Quanji山岳和TarimCraton。Quanji山岳和TarimCraton可能在Neoarchean与北方中国Craton分享类似的外壳的进化历史。

  • 标签: 岩石地球化学特征 锆石HF同位素 塔里木地块 石英闪长岩 中国北方 古元古代
  • 简介:TheShihugolddeposit,situatedintheTaihangMesozoicorogenoftheNorthChinaCraton(NCC),ishostedbyductile-brittlefaultswithinArcheanmetamorphiccorecomplex.Thedepositischaracterizedbygold-bearingquartz-polymetallicsulfidesveins.TheMapenggranitoidsstockandintermediate-basicdikesintrudedthemetamorphicbasementrocks,andarespatiallyrelatedtogoldmineralization.Detailedlaserablationinductivelycoupledplasmamassspectrometry(LAICP-MS)U-Pbzirconagesofthegraniticrocks,dykesandmineralizedquartzveinsinthestudiedarearevealitsmagmaticandmineralizedhistory.Themineralizedquartzveinscontaininheritedzirconswithagesofabout2.55Gaand1.84Ga,probablycomingfromthebasement.ThesetwoPrecambrianeventsarecoevalwiththoseinotherpartsoftheNCC.TheMapenggranitoidstock,thelargestintrusioninthearea,wasemplacedatca.130Ma,andiscoevalwithmagmaticzirconpopulationsfromdioritesandquartzdioritepophyritesinthesameregion.Theca.130MamagmatismandgoldmineralizationweremostlikelyrelatedtoanunderplatingeventthattookplaceintheTaihangorogenatLateMesozoic.Thetimingofgoldmineralizationwithrespecttofelsicmagmatismintheareaissimilartothoseobservedinothermajorgold-producingprovincesintheNCC.ThisepisodeissimultaneouswiththoseintheeasternmarginofNCC,indicativeofawidespreadlateYanshanianmetallogeniceventthatwasaresponsetotheEarlyCretaceouslithosphereintheeasternNCC,inwhichthemesothermalgolddepositswereformedfromsimilartectono-magmaticenvironments.

  • 标签: 锆石U-PB同位素年龄 ICP-MS 金成矿作用 花岗岩类 激光烧蚀 构造意义