The Neo-Proterozoic ophiolites occur in the central and southern Eastern Desert along suture zone as dismemberedmassesinvolcano-sedimentary assemblages.The ophiolite component includes ultramafic rocks mainly serpenti...The Neo-Proterozoic ophiolites occur in the central and southern Eastern Desert along suture zone as dismemberedmassesinvolcano-sedimentary assemblages.The ophiolite component includes ultramafic rocks mainly serpentinites,mafic rocks,minor bodies of trondhjemite,sheeted dykes,metabasalts,and pillow lavas.The Present studies include two ophiolites in Central and southern eastern Desert named Mubarak–El Mayet and Ghadir respectively(Fig.1).The first one named after wadi Mubarak and wadi El Mayet area(55 km north Marsa Alam city)and the second named after Wadi Ghadir(30 km south Marsa Alam city).The dismembered ophiolite components in MubarakEl Mayet mainly composed mainly of serpentinites,ophiolitic metagabbros,sheeted dykes and Pillow lavas.All components occur as thrusted blocks and sheets in metavolcano-sedimentary assemblages(matrix).Gabbros sometimes occur as coarse grained gabbros(appenites)whereas pillows range in size from 30 cm to 1 m(Fig.2a).The second ophiolite sequence expose in Wadi Ghadir and its tributary.It consists of serpentinized peridotites,layered gabbro,massive isotropic gabbro,1fine grained gabbro,sheeted diabase dykes,pillowed basaltic lavas and minor plagiogranites.The serpentinizedperidotites,metapyroxenitesand serpentinites occur as allochthonous dismembered blocks,fragments and sheets in highly sheered metasediments and metavolcanics(mélange)(Fig.2b,c).The massive and layered gabbros occur in the main wadi(Fig.2d,f)and in many places contain some veins and pockets from plagiogranites.The present gabbros intruded by syenogranites from the east.Pillow lavas occur between metasedimentary mélange and ophiolitic gabbros in wadi El Beda as tributary of Wadi Ghadir and sometimes occur as fragments in mélange.The pillows range in size from 40 cm to 1 m(Fig.2f)and are mainly amygdaloidal and porphyritic basalt and spilite.Sheeted dykes cut the gabbros and pillow lavas in the Wadi El Beda and composed mainly from diabase(Fig.2g,h).In the present study,47 samples for major,trace and REE elements from different rock types in Mubarak-El Mayet(18 samples)and Ghadir ophiolite(29 samples)were analyzed.The field work and the geochemical data will discussed in the present work to evaluate the tectonic setting,origin and mantle source for two ophiolite suites.展开更多
Mafic"intrusive rocks",distributed greatly within Dongchuan strata-bound copperfield and really comprising volcanic,subvolcanic and volcano plutonic rocks,should be termed as volcanic-intrusive complex(VIC)....Mafic"intrusive rocks",distributed greatly within Dongchuan strata-bound copperfield and really comprising volcanic,subvolcanic and volcano plutonic rocks,should be termed as volcanic-intrusive complex(VIC).Geology and geochemistry of Jinningian VIC and its relation to Cu ores reaffirm that VIC play an important role in mineralizations,which are not only vein bonanzas deduced from coose beds,but also new orebodies occurred within VIC.Bonanzas of superposing-reworking type and orebodies of magmatic liquation-differentiation type in the depth are suggested to be found in the largely developing VIC area.展开更多
In this paper such minerals as apatite, zircon and biotite from granites were determined and analyzed bysecondary ion mass spectrometry (SIMS) for their isotopic ages, REE composition, trace elements and volatilecompo...In this paper such minerals as apatite, zircon and biotite from granites were determined and analyzed bysecondary ion mass spectrometry (SIMS) for their isotopic ages, REE composition, trace elements and volatilecomponents with an attempt to shed light on the origin and formation environments of the Jinningian granitesin the Yunnan sector of the Kangdian (Xikang- Yunnan) earth's axis. The results show that the apatites,zircons and biotites of different geneses possess different fingerprint characteristics. Some correlations havebeen found between trace elements and volatile components contained in the minerals from granties.展开更多
文摘The Neo-Proterozoic ophiolites occur in the central and southern Eastern Desert along suture zone as dismemberedmassesinvolcano-sedimentary assemblages.The ophiolite component includes ultramafic rocks mainly serpentinites,mafic rocks,minor bodies of trondhjemite,sheeted dykes,metabasalts,and pillow lavas.The Present studies include two ophiolites in Central and southern eastern Desert named Mubarak–El Mayet and Ghadir respectively(Fig.1).The first one named after wadi Mubarak and wadi El Mayet area(55 km north Marsa Alam city)and the second named after Wadi Ghadir(30 km south Marsa Alam city).The dismembered ophiolite components in MubarakEl Mayet mainly composed mainly of serpentinites,ophiolitic metagabbros,sheeted dykes and Pillow lavas.All components occur as thrusted blocks and sheets in metavolcano-sedimentary assemblages(matrix).Gabbros sometimes occur as coarse grained gabbros(appenites)whereas pillows range in size from 30 cm to 1 m(Fig.2a).The second ophiolite sequence expose in Wadi Ghadir and its tributary.It consists of serpentinized peridotites,layered gabbro,massive isotropic gabbro,1fine grained gabbro,sheeted diabase dykes,pillowed basaltic lavas and minor plagiogranites.The serpentinizedperidotites,metapyroxenitesand serpentinites occur as allochthonous dismembered blocks,fragments and sheets in highly sheered metasediments and metavolcanics(mélange)(Fig.2b,c).The massive and layered gabbros occur in the main wadi(Fig.2d,f)and in many places contain some veins and pockets from plagiogranites.The present gabbros intruded by syenogranites from the east.Pillow lavas occur between metasedimentary mélange and ophiolitic gabbros in wadi El Beda as tributary of Wadi Ghadir and sometimes occur as fragments in mélange.The pillows range in size from 40 cm to 1 m(Fig.2f)and are mainly amygdaloidal and porphyritic basalt and spilite.Sheeted dykes cut the gabbros and pillow lavas in the Wadi El Beda and composed mainly from diabase(Fig.2g,h).In the present study,47 samples for major,trace and REE elements from different rock types in Mubarak-El Mayet(18 samples)and Ghadir ophiolite(29 samples)were analyzed.The field work and the geochemical data will discussed in the present work to evaluate the tectonic setting,origin and mantle source for two ophiolite suites.
基金One part of the Nationar"Eight-Five"Key Science and Technology Program(85-901-04-04)。
文摘Mafic"intrusive rocks",distributed greatly within Dongchuan strata-bound copperfield and really comprising volcanic,subvolcanic and volcano plutonic rocks,should be termed as volcanic-intrusive complex(VIC).Geology and geochemistry of Jinningian VIC and its relation to Cu ores reaffirm that VIC play an important role in mineralizations,which are not only vein bonanzas deduced from coose beds,but also new orebodies occurred within VIC.Bonanzas of superposing-reworking type and orebodies of magmatic liquation-differentiation type in the depth are suggested to be found in the largely developing VIC area.
文摘In this paper such minerals as apatite, zircon and biotite from granites were determined and analyzed bysecondary ion mass spectrometry (SIMS) for their isotopic ages, REE composition, trace elements and volatilecomponents with an attempt to shed light on the origin and formation environments of the Jinningian granitesin the Yunnan sector of the Kangdian (Xikang- Yunnan) earth's axis. The results show that the apatites,zircons and biotites of different geneses possess different fingerprint characteristics. Some correlations havebeen found between trace elements and volatile components contained in the minerals from granties.
