Metasomatism and the Chemical Transformation of Rock: The Role of Fluids in Terrestrial and Extraterrestrial Processes PDF
Preview Metasomatism and the Chemical Transformation of Rock: The Role of Fluids in Terrestrial and Extraterrestrial Processes
Lecture Notes in Earth System Sciences Editors: P.Blondel,Bath,UnitedKingdom J.Reitner,G€ottingen,Germany K.St€uwe,Graz,Austria M.H.Trauth,Potsdam,Germany D.Yuen,Minnesota,USA FoundingEditors: G.M.Friedman,BrooklynandTroy,USA A.Seilacher,T€ubingen,GermanyandYale,USA Forfurthervolumes: http://www.springer.com/series/10529 . Daniel E. Harlov (cid:129) Ha˚kon Austrheim Metasomatism and the Chemical Transformation of Rock The Role of Fluids in Terrestrial and Extraterrestrial Processes DanielE.Harlov Ha˚konAustrheim Section3.3 PhysicsofGeologicalProcesses ChemistryandDeutsches UniversityofOslo GeoForschungsZentrum-GFZ Oslo Telegrafenberg Norway Potsdam Germany ISSN2193-8571 ISSN2193-858X(electronic) ISBN978-3-642-28393-2 ISBN978-3-642-28394-9(eBook) DOI10.1007/978-3-642-28394-9 SpringerHeidelbergNewYorkDordrechtLondon LibraryofCongressControlNumber:2012940213 #Springer-VerlagBerlinHeidelberg2013 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionor informationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilar methodologynowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerpts inconnectionwithreviewsorscholarlyanalysisormaterialsuppliedspecificallyforthepurposeofbeing enteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthework.Duplication ofthispublicationorpartsthereofispermittedonlyundertheprovisionsoftheCopyrightLawofthe Publisher’s location, in its current version, and permission for use must always be obtained from Springer.PermissionsforusemaybeobtainedthroughRightsLinkattheCopyrightClearanceCenter. ViolationsareliabletoprosecutionundertherespectiveCopyrightLaw. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publicationdoesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexempt fromtherelevantprotectivelawsandregulationsandthereforefreeforgeneraluse. While the advice and information in this book are believed to be true and accurate at the date of publication,neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityfor anyerrorsoromissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,with respecttothematerialcontainedherein. Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Contents 1 MetasomatismandtheChemicalTransformationofRock: Rock-Mineral-FluidInteractioninTerrestrial andExtraterrestrialEnvironments. . . . . . . . . . . . . . . . . . . . . . . . 1 DanielE.HarlovandHa˚konAustrheim 2 TheChemicalCompositionofMetasomaticFluids intheCrust. . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . 17 BruceW.D.Yardley 3 ThermodynamicModelingandThermobarometry ofMetasomatizedRocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 PhilippeGoncalves,DidierMarquer,EmilienOliot, andCyrilDurand 4 StructuralControlsofMetasomatismonaRegionalScale. . . . . . 93 MikeRubenach 5 MechanismsofMetasomatismandMetamorphismontheLocal MineralScale:TheRoleofDissolution-ReprecipitationDuring MineralRe-equilibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 AndrewPutnisandHa˚konAustrheim 6 GeochronologyofMetasomaticEvents. . . . . . . . . . . . . . . . . . . . . 171 IgorM.VillaandMichaelL.Williams 7 EffectsofMetasomatismonMineralSystemsandTheirHostRocks: AlkaliMetasomatism,Skarns,Greisens,Tourmalinites, Rodingites,Black-WallAlterationandListevenites. . . . . . . . . . . 203 FrancoPirajno 8 MetasomatismWithintheOceanCrust. . . . . . . . . . . . . . . . . . . . 253 WolfgangBach,NielsJ€ons,andFriederKlein v vi Contents 9 MetasomatisminSubductionZonesofSubductedOceanic Slabs,MantleWedges,andtheSlab-MantleInterface. . . . . . . . . 289 GrayE.Bebout 10 MetasomatismDuringHigh-PressureMetamorphism: EclogitesandBlueschist-FaciesRocks. . . . . . . . . . . . . . . . . . . . . 351 ReinerKlemd 11 Prograde,PeakandRetrogradeMetamorphicFluids andAssociatedMetasomatisminUpperAmphibolite toGranuliteFaciesTransitionZones. . . . . . . . . . . . . . . . . . . . . . 415 J.L.R.TouretandT.G.Nijland 12 MantleMetasomatism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471 SuzanneY.O’ReillyandW.L.Griffin 13 MappingtheDistributionofFluidsintheCrust andLithosphericMantleUtilizingGeophysicalMethods. . . . . . . 535 MartynUnsworthandSte´phaneRondenay 14 AHydromechanicalModelforLowerCrustalFluidFlow. . . . . . 599 J.A.D.ConnollyandY.Y.Podladchikov 15 MetasomatismintheEarlySolarSystem:TheRecord fromChondriticMeteorites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 659 AdrianJ.BrearleyandAlexanderN.Krot Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791 Chapter 1 Metasomatism and the Chemical Transformation of Rock: Rock-Mineral-Fluid Interaction in Terrestrial and Extraterrestrial Environments DanielE.HarlovandHa˚konAustrheim 1.1 Metasomatism The term metasomatism comes from the Greek metά (meta ¼ change) and sῶma (soma ¼ body).ThetermwasoriginallycoinedbyC.F.NaumanninLehrbuchder Mineralogie, published by Engelman in Leipzig in 1826. The current definition of metasomatism,accordingtotheIUGSSubcommissionontheSystematicsofMeta- morphicRocks(SSMR),is“ametamorphicprocessbywhichthechemicalcompo- sitionofarockorrockportionisalteredinapervasivemannerandwhichinvolves theintroductionand/orremovalofchemicalcomponentsasaresultoftheinteraction oftherockwithaqueousfluids(solutions).Duringmetasomatismtherockremains inasolidstate.”MetamorphismcomesfromtheGreekmetά(meta ¼ change)and morfe(morphe ¼ form)andisdefinedbytheIUGSSSMRas“aprocessinvolving changesinthemineralcontent/compositionand/ormicrostructureofarock,domi- nantlyinthesolidstate.Thisprocessismainlyduetoanadjustmentoftherockto physical conditions that differ from those under which the rock originally formed andthatalsodifferfromthephysicalconditionsnormallyoccurringatthesurfaceof theEarthandinthezoneofdiagenesis.Theprocessmaycoexistwithpartialmelting andmayalsoinvolvechangesinthebulkchemicalcompositionoftherock.”From thesetwodefinitionsitisobviousthatmetasomatismandmetamorphismofsilicate rocks are commonly interrelated with each other. However, they can also be mutually exclusive. For example, metamorphism can be isochemical such that the chemical and isotopic characteristics of the protolith sedimentary or igneous D.E.Harlov(*) Section3.3ChemistryandDeutsches,GeoForschungsZentrum-GFZ,Telegrafenberg,Potsdam D-14473,Germany e-mail:[email protected] H.Austrheim PhysicsofGeologicalProcesses(PGP),UniversityofOslo,Blindern,1048,OsloN-0316,Norway e-mail:[email protected] D.E.HarlovandH.Austrheim,MetasomatismandtheChemical 1 TransformationofRock,LectureNotesinEarthSystemSciences, DOI10.1007/978-3-642-28394-9_1,#Springer-VerlagBerlinHeidelberg2013 2 D.E.HarlovandH.Austrheim lithologies are retained. Also, the chemical changes seen during the high-grade transition of metamorphic rocks from amphibolite- to granulite-facies, can be due totheremovaloffluid-richpartialmelts.Incontrast,sedimentdiagensis,fluid-aided deposition of ore veins or ore deposits, sea floor alteration, and alteration of surroundingrockbyhotspringsormeteoricfluidsarefluid-dominatedmetasomatic process,whicharegenerallynotconsideredtobemetamorphic. Fluid-aided mass transfer and subsequent mineral re-equilibration are the two definingfeaturesofmetasomatisminsilicaterocksandmustbepresentinorderfor metamorphismtooccur.Takingintoaccountgeologicaltimescales,theamountof fluidrequiredneednotbegreat(considerablylessthan0.01%ofthetotalvolumeof the rock) nor even in continuous flow but the fluid must be able to actively flow along grain boundaries and be chemically reactive with respect to the minerals it encounters such that efficient mass transfer is promoted. If the fluids are quite chemically reactive the possibility exists of fluid flow through the minerals them- selvesintheformofmigratingfluidinclusionsorporosity(seeChap.14).Natural observation, coupled with experimental replication and thermodynamic verifica- tion, allows for insights into the chemistry and physical nature of the metasomatising fluid as a function of P-T conditions and the general host rock chemistrytobeobtained.Ingeneral,thelimitedortotalre-equilibrationofsilicate, oxide,sulfide,andphosphatemineralsduetothepassageoffluidstakesplaceasthe result ofacoupleddissolution-reprecipitationprocess (see Chap. 5).Evidence for the passage of fluids through rock can take the form of altered mineral trace- element chemistry, partial to total re-equilibration of mineral phases, reaction textures along mineral grain boundaries, and/or trails of fluid inclusions through minerals.Lackoffluidsgenerallymeanslackofre-equilibrationbetweenminerals andconsequentlyalackofinformationregardingthetrueP-T-Xhistoryoftherock. Coupledwithigneousandtectonicprocesses,metasomatismhasplayedamajor roleintheformationoftheEarth’scontinentalandoceaniccrustandthelithospheric mantle as well as in their ongoing evolution and consequent mutual relationships with respect to each other. Metasomatic processes can include ore mineralization (seeChap.7),alterationofoceaniclithosphere(seeChap.8),andmasstransportin andalterationofsubductedoceanicandcontinentalcrustandtheoverlyingmantle wedge (see Chaps. 9 and 10). The latter has subsequent implications for mass transport, fluid flow, and volatile storage in the lithospheric mantle overall (see Chap.12),aswellasbothregionalandlocalizedcrustalmetasomatism(seeChap.4). Metasomaticalterationofaccessoryminerals,suchaszircon,monazite,xenotime, or apatite or major minerals, such as micas, feldspars, and amphiboles, can allow for the dating of metasomatic events and gives additional information regarding the chemistry of the fluids responsible (see Chap. 6). Indications of massive fluid flow and subsequent total alteration of the original rock include skarns, greisens, and the serpentinization of oceanic crust (see Chaps. 7 and 8). Evidence for widespread and pervasive metasomatism in the lithospheric mantle is naturally coupled withsimilarevidenceinhigh-pressurerockssuchasgranulite-,eclogite-, andblueschist-faciesrocks(seeChaps.10and11).UndersuchP-Tconditions,the boundarybetweenwhatisconsideredafluidandwhatisconsideredameltbecomes 1 MetasomatismandtheChemicalTransformationofRock 3 significantlyblurred.Here,criticalandsupercriticalonephaseandmultiphaseCO - 2 H O-NaCl-KCl-CaCl fluids can play an important role with respect in enabling 2 2 mineral reactions such as the solid-state conversion of biotite and amphiboles to orthopyroxene and clinopyroxene during granulite-facies metamorphism (see Chap. 11). Evidence for similar fluids in the lithospheric mantle include veins of obviousmetasomaticoriginthatcontainabundantmegacrystsofapatiteenrichedin CO andCl.Inthecaseofultramaficmassifs,whichexposelargevolumesofupper 2 mantlematerial,theeffectsoffluidinfiltrationcanbetracedcoherentlyoverscales ofmeterstokilometers(seeChap.12).Presentdaymovementoffluidsinboththe lithospheric mantle and deep to middle crust can be observed by geophysical techniquessuchaselectricalresistivityandseismicmeasurements(seeChap.13). Suchobservations,alongwithmodeling(seeChap.14),helptofurtherclarifythe pictureofactualmetasomaticprocessesinferredfrombasicpetrographic,mineral- ogical,andgeochemicaldata. Metasomatism and probable metamorphism is not limited to terrestrial environments but can occur in extraterrestrial environments where H O exists in 2 liquid form. The best studied of these extraterrestrial environments are the asteroids, for which numerous examples from meteorites exist (see Chap. 15). This does not exclude other terrestrial worlds such as Mars, Europa ganymede, Callisto,Enceladus,orTitanonorinwhichH Ocanexistasaliquid.Presumably 2 metasomatismcouldandprobablydoesoccurontheseworlds.InthecaseofMars boththeSpiritandOpportunityRovershavespentthelast8yearsprovidingample evidenceforMars’H O-richpast(seehttp://marsrovers.jpl.nasa.gov/home/). 2 Thegoalofthisvolumeistobringtogetheradiversegroupofexpertsontherole of fluids in shaping terrestrial and extraterrestrial environments; each of whom is responsible for a specific chapter covering some aspect of metasomatism. Each chapterisdesignedtoprovideanup-to-datereviewoftheeffectsofmetasomatism on both terrestrial and extraterrestrial environments. In that respect this volume shouldberegardedasastartingoffpointforthestudentorprofessionalinterestedin obtaining a firm foundation regarding the various areas of metasomatism covered bythechaptersinthisbook.Subsequentlyitshouldserveasabasisforrichresearch opportunitiesintheyearstocome.Inthefollowingsectionseachofthechaptersis summarizedpertheuniqueviewpointoftheindividualauthors. 1.2 The Chemical Composition of Metasomatic Fluids in the Crust: Chapter 2 Any crustal fluid can give rise to metasomatism when it migrates from one rock typetoanother,andmetasomatismisnormallyassociatedwithpastfluidflowpaths, suchasfractures,faults,shearzones,orlithologiesthatweremorepermeablethan those around them. This chapter specifically concerns infiltration metasomatism, driven by advection of fluids. Fluid compositions can be buffered by local host
The list of books you might like
