Intralithospheric differentiation and crustal growth: Evidence from the Borborema province, northeastern Brazil

Abstract

Research Article| June 01, 2000 Intralithospheric differentiation and crustal growth: Evidence from the Borborema province, northeastern Brazil Sérgio P. Neves; Sérgio P. Neves 1Department of Geology, Federal University of Pernambuco, 50740-530 Recife, PE, Brazil Search for other works by this author on: GSW Google Scholar Gorki Mariano; Gorki Mariano 1Department of Geology, Federal University of Pernambuco, 50740-530 Recife, PE, Brazil Search for other works by this author on: GSW Google Scholar Ignez P. Guimarães; Ignez P. Guimarães 1Department of Geology, Federal University of Pernambuco, 50740-530 Recife, PE, Brazil Search for other works by this author on: GSW Google Scholar Adejardo F. da Silva Filho; Adejardo F. da Silva Filho 1Department of Geology, Federal University of Pernambuco, 50740-530 Recife, PE, Brazil Search for other works by this author on: GSW Google Scholar Silvana C. Melo Silvana C. Melo 1Department of Geology, Federal University of Pernambuco, 50740-530 Recife, PE, Brazil Search for other works by this author on: GSW Google Scholar Geology (2000) 28 (6): 519–522. https://doi.org/10.1130/0091-7613(2000)28<519:IDACGE>2.0.CO;2 Article history received: 15 Oct 1999 rev-recd: 06 Mar 2000 accepted: 14 Mar 2000 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Sérgio P. Neves, Gorki Mariano, Ignez P. Guimarães, Adejardo F. da Silva Filho, Silvana C. Melo; Intralithospheric differentiation and crustal growth: Evidence from the Borborema province, northeastern Brazil. Geology 2000;; 28 (6): 519–522. doi: https://doi.org/10.1130/0091-7613(2000)28<519:IDACGE>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyGeology Search Advanced Search Abstract Thousands of cubic kilometers of high-K calc-alkalic magmas intruded the Borborema Province (northeastern Brazil) during the Neoproterozoic Brasiliano orogeny. They make up large batholiths in which mantle-derived mafic to intermediate rocks coexist with a larger amount of granitoids. The relatively low silica contents (61–70 wt% SiO2) and moderate to high compatible element concentrations (0.3–3.5 wt% MgO, 1.5–3.8 wt% CaO, as much as 150 ppm of Cr) of the granitoids indicate that they contain an appreciable mantle component. The similar trace element geochemical (high contents of incompatible trace elements) and isotopic (strongly negative ϵNd values) signatures of mafic and felsic rocks combined with geochemical modeling suggest that (1) the mafic and felsic rocks are genetically linked, (2) the granitic magmas were produced by 20%–30% partial melting from a source having geochemical characteristics similar to the mafic rocks, and (3) mingling and mixing of felsic magmas with subsequent batches of mafic magmas yielded the silica-poor granitoids. Isotopic data preclude involvement of the asthenosphere in the genesis of the mafic melts and instead indicate their derivation from an old, enriched lithospheric mantle. Therefore, addition of mantle material to the crust occurred through internal lithospheric differentiation, in contrast with conventional crustal-growth models. You do not currently have access to this article.