简介:AsymplectiteofpyriteandmagnetiteinthemassivesulphideoreoftheMashanmine,AnhuiProvince,isinterpretedtohavebeenformedbytheirreplacingearlierpyrrhotite.Thecompositionsofpyrrhotite,pyriteandmagnetiterelatedtothistexturearegivenbyelectronmicroprobeanalysis.Suchatextureislikelytobeformedwhentheore-formingsystemreachesthethree-phasepointofpyrrhotite,pyriteandmagnetitefromthepyrrhotitestabilityfield.Theverysmallprobabilityforthesystemtoreachthispointcouldbeusedtoaccountfortherareoccurrenceofsuchsymplectiteinnaturalores.
简介:Pressuresolutionisacommonphenomenoninmassivesulphidezinc-leaddepositsofwesternCanadaandmayhavebeenanimportantfactorleadingtothemobilizationofore-formingmaterialsduringdiagenesis,deformationandmetamorphismofsedimentaryores.Thecontrolofductileshearzonesovergoldmineralizationcouldbeexplainedinviewofpressuresolutionofgold-bearingminer-alsundershearingstressandthetesultantmobilizationofthismetal.