Age dependence of the composition of continental crust - Evidence from Nd isotopic variations in granitic rocks

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

14

Abundance, Earth Crust, Geochemistry, Geochronology, Neodymium Isotopes, Samarium Isotopes, Graphite, Magma, Rare Earth Elements

Scientific paper

Data on Nd-143/Nd-144 values from granitoid rocks emplaced into the continental crust samples of different ages were used to deduce the Sm/Nd ratio of the crust, which is a sensitive indicator of the REE pattern. It was found that the values of the Sm/Nd ratio in the granite magma sources in the continental crust increase with decreasing age from the Early Archean to the Late Proterozoic, the trend which is opposite to that inferred for the crust from the REE patterns in sedimentary rocks. The isotopic data, combined with the crustal age distribution, indicate that the Sm/Nd value of the bulk continental crust is not lower than 0.60 times the chondritic value. This limit and the estimates of the Nd concentration of the crust (which are between 20 and 25 ppm) are consistent with the mass balance that equates the Nd in the continents to that missing from the upper mantle down to a depth of about 700 km.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Age dependence of the composition of continental crust - Evidence from Nd isotopic variations in granitic rocks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Age dependence of the composition of continental crust - Evidence from Nd isotopic variations in granitic rocks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Age dependence of the composition of continental crust - Evidence from Nd isotopic variations in granitic rocks will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1825885

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.