High-grade Granites Research Articles

Comment and Reply on “Missing Eu anomaly and Archean high-grade granites”

Comment and Reply on “Missing Eu anomaly and Archean high-grade granites”

Comment and Reply on “Missing Eu anomaly and Archean high-grade granites”

Research Article| July 01, 1986 Comment and Reply on “Missing Eu anomaly and Archean high-grade granites”: COMMENT H. R. Rollinson H. R. Rollinson 1School of Geography and Geology, Faculty of Sciences, College of St Paul and St Mary, The Park, Cheltenham, Gloucestershire GL52 2RH, England Search for other works by this author on: GSW Google Scholar Geology (1986) 14 (7): 628–629. https://doi.org/10.1130/0091-7613(1986)14<628:CAROME>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation H. R. Rollinson; Comment and Reply on “Missing Eu anomaly and Archean high-grade granites”: COMMENT. Geology 1986;; 14 (7): 628–629. doi: https://doi.org/10.1130/0091-7613(1986)14<628:CAROME>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract No Abstract Available. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Missing Eu anomaly and Archean high-grade granites

Granites emplaced in low-grade (granite-greenstone) Archean terranes typically exhibit negative Eu anomalies, and such Eu anomalies have been transmitted to post-Archean cratonic sediments by weathering and erosion. Because average continental crust does not exhibit an Eu anomaly, a complementary reservoir with a positive Eu anomaly must exist to balance the low-grade granites. Neither the upper mantle nor average Archean lower crust appears to represent this reservoir. Archean lower crustal rocks, which are dominantly plutonic rocks of tonalitic composition, have REE distributions indicative of a mafic parentage. However, Archean high-grade granites in southern India exhibit the required positive Eu anomalies and may be representative of a widespread positive Eu anomaly reservoir in the lower crust. Geochemical model studies indicate that Archean low- and high-grade granites may represent residual liquid and cumulate, respectively, from the fractional crystallization of a granite parent magma produced by partial melting of tonalitic rocks in the lower crust. Such melting may occur at the wave front of a CO 2 -rich fluid that dehydrates the lower crust and produces granulites.