Age and significance of amphibolites in the bolu massif (İstanbul Zone, NW Turkey)
Age and significance of amphibolites in the bolu massif (İstanbul Zone, NW Turkey)
dc.contributor.advisor | Topuz, Gültekin | |
dc.contributor.advisor | Wang, Jia-Min | |
dc.contributor.author | Demirkaya, İnal | |
dc.contributor.authorID | 602191003 | |
dc.contributor.department | Geodynamics | |
dc.date.accessioned | 2024-11-18T13:03:33Z | |
dc.date.available | 2024-11-18T13:03:33Z | |
dc.date.issued | 2022-07-06 | |
dc.description | Thesis (M.Sc.) -- İstanbul Technical University, Graduate School, 2022 | |
dc.description.abstract | The Bolu Massif represents the Late Neoproterozoic crystalline basement of the Istanbul Zone (NW Turkey), and is made up of two tectonometamorphic units which are separated by a major tectonic line. The lower tectonometamorphic unit comprises amphibolite-facies metamorphic rocks which are dominated by the migmatitic amphibolite and locally trondhjemite. On the other hand, the overlying tectonometamorphic unit comprises greenschist-facies mafic to felsic metavolcanic rocks intruded by a huge granitoid of Late Neoproterozoic age. This study deals with the metamorphic evolution of the underlying amphibolite-facies tectonometamorphic unit. The amphibolite-facies tectonometamorphic unit comprises migmatitic amphibolite (ca. 80% of the exposure area) and concordant to crosscutting trondhjemite sills/dykes/stocks (ca. 20% of the exposure area). Although this amphibolite unit was formerly interpreted to the crustal part of an ophiolite, rare earth element patterns and multi-element variation diagrams involving fluid immobile elements differ from the well-documented ophiolites. The geochemical features of these voluminous amphibolites are more consistent with those in intra-oceanic arcs and magmatic arcs. U-Pb dating of zircons from four trondhjemite samples and from three amphibolite samples consistently yielded ages of 255-260 Ma (Middle to Late Permian). Only zircons from one amphibolite sample defined a discordia with an upper intercept age of 554 ± 34 Ma (2) (Late Neoproterozoic-Cambrian). The geochronological data shows that the amphibolite-facies tectonometamorphic unit does not represent the Late Neoproterozoic basement of the Istanbul Zone. It is related to Late Palaeozoic to Late Mesozoic orogenic events. | |
dc.description.degree | M.Sc. | |
dc.identifier.uri | http://hdl.handle.net/11527/25644 | |
dc.language.iso | en_US | |
dc.publisher | Graduate School | |
dc.sdg.type | Goal 7: Affordable and Clean Energy | |
dc.sdg.type | Goal 14: Life Below Water | |
dc.subject | Bolu massif | |
dc.subject | Bolu masifi | |
dc.subject | Amphibolites | |
dc.subject | Amfibolitler | |
dc.title | Age and significance of amphibolites in the bolu massif (İstanbul Zone, NW Turkey) | |
dc.title.alternative | Bolu masifi'ndeki (İstanbul Zonu, KB Türkiye) amfibolitlerin yaşı ve önemi | |
dc.type | Master Thesis |