气候变化领域集成服务门户(CCPortal): Geochemical and isotope evidence for mantle-derived source rock of high-K calc-alkaline I-type granites; Pernambuco

CCPortal

DOI	10.1007/s00531-019-01696-9
	Geochemical and isotope evidence for mantle-derived source rock of high-K calc-alkaline I-type granites; Pernambuco–Alagoas Domain; northeastern Brazil
	Silva T.R.; Ferreira V.P.; Lima M.M.C.; Sial A.N.
发表日期	2019
ISSN	14373254
起始页码	1095
结束页码	1120
卷号	108 期号:4
英文摘要	We report whole-rock major, trace, mineral, and isotope chemistries of the Jacaré dos Homens, and Santo Antonio granitic rocks from the Águas Belas–Canindé batholith, Pernambuco–Alagoas Domain of the Borborema Province, northeastern Brazil. These rocks exhibit low-angle foliation, suggesting emplacement under a regional strain field, associated with transpressive deformation tied to the onset of the Brasiliano orogeny. Both rocks are dominantly made up of K-feldspar, quartz, and plagioclase with biotite as the main mafic phase and minor hornblende. The Jacaré dos Homens orthogneiss displays magnesian, slightly peraluminous, and alkali-calcic character, while the Santo Antonio granite is magnesian, metaluminous to slightly moderately peraluminous and alkali-calcic to alkalic. These granitic rocks are enriched in alkalis (up to 10.28 wt%), mg#, Rb, Ba, Sr, Th, and LREE, and depleted in HREE and HFSE, with distinct Nb, Ta, and Ti depletion. Decreasing MgO, CaO, TiO2, Na2O, Fe2O3T, P2O5, Al2O3, Sr, Zr, and Hf with increasing SiO2 are consistent with fractional crystallization of biotite, amphibole, plagioclase, apatite, zircon, titanite, and Fe–Ti oxides. U–Pb zircon dating of the Jacaré dos Homens and Santo Antonio rocks yielded concordia ages of 642.4 ± 3 Ma and 636 ± 4 Ma, respectively. The isotope data for the Jacaré dos Homens orthogneiss yielded an Nd-model age of 1.21 Ga with slightly negative εNd(642 Ma) of − 1.58, initial 87Sr/86Sr ratios of 0.7068, and δ18O (zircon) value of + 7.0‰ VSMOW. The isotope data for Santo Antonio pluton yielded Nd-model ages between 0.96 and 1.07 Ga, with εNd(636 Ma) from + 1.17 to − 0.67, initial 87Sr/86Sr ratios from 0.7048 to 0.7056, and δ18O (zircon) value of + 5.0 to 5.9‰ VSMOW. Altogether, the petrological, geochemical, and isotopic data are typical of I-type granites. We propose that the studied granitic rocks were derived from mantle-derived medium- to high-K basaltic lower crust of Stenian/Tonian (Jacaré dos Homens) or Tonian (Santo Antonio) ages and that partial melting was triggered by the uplift of asthenosphere and underplating of lithospheric mantle. The migration and buoyancy-driven ascent of the magma to their present level were probably favored by the Jacaré dos Homens shear zone. © 2019, Geologische Vereinigung e.V. (GV).
英文关键词	Basaltic source rocks; High-K calc-alkaline magmatism; Northeastern Brazil; Sr–Nd–O isotopes; U–Pb ages
语种	英语
scopus关键词	calcium; geochemistry; I-type rock; magma; magmatism; mantle structure; neodymium isotope; oxygen isotope; source rock; strontium isotope; uranium-lead dating; Brazil
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147840
作者单位	NEG-LABISE, Department of Geology, Federal University of Pernambuco, Av. da Arquitetura s/n, Cidade Universitária, Recife, PE 50740-550, Brazil
推荐引用方式 GB/T 7714	Silva T.R.,Ferreira V.P.,Lima M.M.C.,等. Geochemical and isotope evidence for mantle-derived source rock of high-K calc-alkaline I-type granites; Pernambuco–Alagoas Domain; northeastern Brazil[J],2019,108(4).
APA	Silva T.R.,Ferreira V.P.,Lima M.M.C.,&Sial A.N..(2019).Geochemical and isotope evidence for mantle-derived source rock of high-K calc-alkaline I-type granites; Pernambuco–Alagoas Domain; northeastern Brazil.International Journal of Earth Sciences,108(4).
MLA	Silva T.R.,et al."Geochemical and isotope evidence for mantle-derived source rock of high-K calc-alkaline I-type granites; Pernambuco–Alagoas Domain; northeastern Brazil".International Journal of Earth Sciences 108.4(2019).