Regional S-type granites in the Ecuadorian Andes: Possible remnants of the breakup of western Gondwana

Autor:	F. Viteri, N.J. Fortey, S.M. Harrison, J.A. Aspden, M. Litherland
Rok vydání:	1992
Předmět:	Metamorphic rock Muscovite Geochemistry Geology engineering.material Gondwana Igneous rock Batholith Absolute dating engineering Mesozoic Biotite Earth-Surface Processes
Zdroj:	Journal of South American Earth Sciences. 6:123-132
ISSN:	0895-9811
DOI:	10.1016/0895-9811(92)90002-g
Popis:	Reconnaissance geological mapping of the Ecuadorian Cordillera Real has established the presence of a previously unrecognized regional suite of variably deformed granitoids for which poorly constrained RbSr whole-rock data indicate a minimum Early Jurassic age of 200 ± 12 Ma (initial ratio = 0.7120). This suite, which is associated with low- to medium-grade, semipelitic metamorphic rocks, is dominated by peraluminous monzogranites containing biotite ± garnet ± muscovite. Geochemically, these granites are S-types and can be readily distinguished from juxtaposed I-type granitoids of the Middle-Upper Jurassic Zamora, Abitagua, and Azafran batholiths located immediately to the east. Intrusion of these S-type granites may be related to the breakup of western Gondwana.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d5affbf4e2a8be0aec8be0d5293e8d96 https://doi.org/10.1016/0895-9811(92)90002-g Zobrazit plný text záznamu