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:从一个锰小瘤的层从菲律宾的海挖出(16°56′N,129°48′E;水深度,5700m)并且45个体积小瘤从近海Minami-Torishima岛,日本(23°3′N,153°22′E;水深度,1200m)化学上被分析,他们的起源基于geochemical限制被讨论。一般来说,,Cu,Ni,Zn和瞬间趋于与增加Mn内容增加元素(REE)少些显示出的公司,Pb,Ba,V,Sc,Th,和稀土元素有增加Mn内容的变化。来自菲律宾的海的小瘤42H有平均Mn/Fe比率结束到1并且显示出一个积极Ce异例,建议占优势的氢的起源。230Th前和230Th前/232在小瘤42H的外部∼0.3公里的Th比率显示∼1.7mm/Myr的稳定的生长率。小瘤E30从近海Minami-Torishima被更低的Mn,Fe,Mn/Fe(0.53)和Mo/V(0.2)比率描绘但是更高的P和Cu/Ni(0.31)相对来自那个区域的另外的小瘤的比率。E30的Ce内容是不平常地低的(82ppm)什么时候与来自区域和它的另外的小瘤相比是唯一的小瘤,与一个否定Ce异例(−0.64)分析了。把那个大多数基于我们建议的geochemical数据小瘤从近海除了E30,Minami-Torishima主要具有氢的起源,它被热水的输入,和E45统治,它关于35%热水的贡献有。