Trace element signatures of mantle xenoliths along an east-west transect extending from the Sierra Nevada to the Colorado Plateau were investigated in this study. Those beneath the Sierra Nevada are highly enriched in fluid-mobile elements (Cs, Pb, U, and Sr) and, in particular, are characterized by low U/Pb and high Sr/Nd. These signatures imply that aqueous fluids derived by dehydration of se...

Slow antiferromagnetic dynamics in the low temperature tetragonal phase of La 2−x Sr x CuO 4 as revealed by ESR of Gd spin probes Abstract Measuring the ESR of Gd spin probes we have studied the magnetic properties of the copper oxide planes in the low temperature tetragonal (LTT) phase of Eu doped La 2−x Sr x CuO 4. The data give evidence that at particular levels of Sr and Eu doping the frequ...

introduction the bornaward area is located in the northeastern iran (in the khorasan razavi province) 28 km northwest of the city of bardaskan at 57˚ 46΄ to 57˚ 52΄ n latitude and 35˚ 21΄ to 35˚ 24΄e longitude. the taknar structural zone, situated in the north central iranian micro continent, is part of the lut block (forster, 1978). the taknar zone is an allochthonous block bounded by the daro...

صلاخلا ـ ة : ُّ دعتُ ل ثم ةيعيبطلا تاغللا ةجلاعم تاقيبطت نم ديدعلل ايساسأ انوكم ةيعوضوملا ةئزجتلا قيبطت تامولعملا عاجرتساو صوصنلا صيخلت . نم فدهلا وه ثحبلا اذ ه قت و مي ةيعوضوملا ة ئزجتلا تا يمزراوخ ة يلاعف ضوملا دودحلا ى لع فرعتلا يف ة يبرعلا صوصنلا لخاد ةيعو . م تو قايس لا اذ ه يف ة فلتخم رداصم نم ةيبرع صوصن ةسمخ لخاد اهنوظحلاي يتلا ةركفلا وأ عوضوملا تاريغت ىلع فرعتلل ةيبرعلا ةغللا ءارق نم ة...

The dehydration of the lower crust and the assimilation of crustal materials into ascending magmas are two geologic phenomenon which lead to vertical mass transport and potentially, geochemical stratification of continental crust. LOWER CRUSTAL XENOLITHS, KILBOURNE HOLE This integrated Sr-Nd-Pb isotope study of paragneiss xenoliths from Kilbourne Hole maar, New Mexico, is the first of its kind ...