Na and Cr contents in clinopyroxenes from peridotites: A possible discriminant between ``sub-continental'' and ``sub-oceanic'' mantle

Computer Science

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

19

Scientific paper

The compilation of data available in the literature and new analyses show that clinopyroxenes are significantly richer in Na and poorer in Cr in peridotites associated with high-grade metamorphic rocks than in ultramafites from oceanic environments, considered as ``sub-continental'' or ``sub-oceanic'' mantle, respectively. Two distinctive fields can be drawn in the Na-Cr plot. This fact is related to the large amount of basic magma provided by the oceanic mantle along the mid-oceanic ridges.
Application of this Na-Cr diagram to clinopyroxenes from peridotites in orogenic belts and appearing as xenoliths in volcanic rocks and kimberlites (``nodules'') allows us to specify their origin, taking into consideration that the clinopyroxene composition is controlled by several factors each of which gives rise to a particular trend: P-T. conditions, mineral facies, partial melting and crystal fractionation, metasomatism. It appears that oceanic-type mantle may be found under continents in extensional areas having evolved towards rift systems, and in ophiolites. The latter exhibit different degree of depletion related to their formation in two main geotectonic situations: mid-oceanic ridges and active margin systems.

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

Na and Cr contents in clinopyroxenes from peridotites: A possible discriminant between ``sub-continental'' and ``sub-oceanic'' mantle 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 Na and Cr contents in clinopyroxenes from peridotites: A possible discriminant between ``sub-continental'' and ``sub-oceanic'' mantle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Na and Cr contents in clinopyroxenes from peridotites: A possible discriminant between ``sub-continental'' and ``sub-oceanic'' mantle will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-782121

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