We present evidence for a thick ( 100 km) sequence of cogenetic rocks which make up the root of the Sierra Nevada batholith of California. The Sierran magmatism produced tonalitic and granodioritic magmas which reside in the Sierra Nevada upperto midcrust, as well as deep eclogite facies crust/upper mantle ma®c±ultrama®c cumulates. Samples of the ma®c±ultrama®c sequence are preserved as xenolit...

Continental flood basalts and mid-ocean ridge (MOR) tholeiitic basalts have distinctly different 14 3 Ndf1 44 Nd which may permit a priori distinctwn between '"continental" and "oceanic" igneous rocks. Initial 14 3 NdJI 4 4 Nd of continental igneous rocks through time fall on a Sm/Nd evolution curve with chondritic REE abundance ratio. These observations indicate that many continental igneous r...

Trace-element and Nd-Sr-Pb isotopic data for mafic lavas from the Mascarene island of Mauritius reveal that the shield-stage Older Series (with 143Nd/144Nd = 0.512827 to 0.512853, 87Sr/86Sr = 0.70412 to 0.70433, and 206Pb/204Pb = 18.771 to 19.024) is geochemically very similar to the shield-building lavas of the younger island of Réunion. The post-shield Intermediate and Younger Series lavas of...

BACKGROUND Isotopes can provide unique solutions to fundamental problems related to the ecology and evolution of migration and dispersal because prior movements of individuals can theoretically be tracked from tissues collected from a single capture. However, there is still remarkably little information available about how and why isotopes vary in wild animal tissues, especially over large spat...

In our previous study on petrogenesis of quartz syenite and granite porphyry, the host rocks Late Mesozoic Shapinggou Mo deposit in Qinling–Dabie orogenic belt, we found that initial Sr isotopic composition is strongly affected by degree K-alteration. Here, provide further evidence their minerals to investigate geochemical behaviour trace elements isotopes during alteration explain phenomenon d...

Study of lamproites from Leucite Hills, Wyoming, indicates that the isotopic compositions of some specimens have been modified due to the alteration and/or the presence of secondary carbonate impurities within the whole rocks. Leachate test shows that while phlogopite lamproites are not affected by secondary processes, the transitional madupitic lamproites from Middle Table Mountain and on...