Geochemical and petrographic features of metabasalts within units of the Ankara Melange

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Authors:Capan, U. Z.; Floyd, P. A.
Author Affiliations:Primary:
Univ. Hacettepe, Dep. Geol. Eng., Ankara, Turkey
Volume Title:Ofioliti
Source:Ofioliti, 10(1), p.3-12. Publisher: Pitagora Editrice, Bologna, Italy. ISSN: 0391-2612
Publication Date:1985
Note:In English. 2 p. refs.; illus. incl. 46 anal., 2 tables, geol. sketch maps
Summary:Low-grade metabasalts from the Ankara group (Trias) and the Kiliclar group (Upper Cretaceous) tectonic units of the Ankara melange can, to some extent, be petrographically and chemically distinguished. Basalts within the Ankara group are predominantly deep-water aphyric alkaline pillow lavas characterized by a within-plate oceanic island chemistry. They are interpreted as representing seamounts on the Izmir-Ankara branch of the early N Neo-Tethys oceanic crust. Kiliclar group basalts are more variable and exhibit alkaline, tholeiitic and calc-alkaline basalt types with varied phenocryst assemblages. Apart from a few tholeiites with enriched-MORB affinities, the majority of the alkaline and tholeiitic basalts are representative of oceanic islands. The calc-alkaline basalt megaclasts are geographically restricted in the Kiliclar unit and may represent fragmentation of a continental margin or arc originally part of the Sakarya continental slab within Neo-Tethys. Both melange units are thus characterized by essentially non-ophiolitic fragments that were probably dismembered in an accretionary wedge in front of the Sakarya continent. (Authors' abstract) [C.N.]
Subjects:Basalts; Calc-alkalic composition; Chemical ratios; Cretaceous; Igneous rocks; Lava; Low-grade metamorphism; Major elements; Melange; Mesozoic; Metabasalt; Metaigneous rocks; Metamorphic rocks; Metamorphism; Minor elements; Petrology; Pillow lava; Tholeiitic basalt; Triassic; Upper Cretaceous; Volcanic rocks; Asia; Middle East; Turkey
Abstract Numbers:87M/5036
Record ID:1987070238
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom, Reference includes data from PASCAL, Institute de l'Information Scientifique et Technique
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