Macro to micro-scale insights into granite petrogenesis; a case study from the Caledonian Ross of Mull granite (ROMG), Argyllshire, Northwest Scotland

Zaniewski, Adam

Macro to micro-scale insights into granite petrogenesis; a case study from the Caledonian Ross of Mull granite (ROMG), Argyllshire, Northwest Scotland

dc.check.embargoformat	Embargo not applicable (If you have not submitted an e-thesis or do not want to request an embargo)	en
dc.check.info	Not applicable	en
dc.check.opt-out	Not applicable	en
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dc.contributor.advisor	Reavy, John	en
dc.contributor.advisor	Finch, Adrian	en
dc.contributor.advisor	Gamble, John	en
dc.contributor.author	Zaniewski, Adam
dc.contributor.funder	University College Cork	en
dc.contributor.funder	European Commission	en
dc.date.accessioned	2018-09-04T11:53:51Z
dc.date.available	2018-09-04T11:53:51Z
dc.date.issued	2018
dc.date.submitted	2018
dc.description.abstract	The Ross of Mull Granite (ROMG) occupies the largest part of the Pre-Paleogene inlier of the Ross of Mull peninsula, Isle of Mull, Argyllshire, Scotland and is the most south-westerly of the Northwest Highland Caledonian granitoid complexes. Re-mapping of the entire intrusion (Zaniewski et al. 2006) has revealed a reverse zonation of facies resulting from mafic-felsic magma interaction prior to ascent at the proposed intersection of the Sound of Iona Fault and Great Glen Fault with north-eastward emplacement of flattish sheets into high-grade lithologies of the Moine Supergroup. Subsequent to mapping, Quantitative X-Ray Diffractometry (QXRD) has re-enforced modal classifications of Zaniewski et al. (2006). To further examine if this phenomenon is also encoded at the micro-scale (crystal), and if a correlation exists with macro-scale (field) studies, in-situ elemental and Pb-Pb isotopic zoning in magmatic feldspars from all ROMG components were analysed. The following micro-scale studies have been undertaken: (a) detailed textural study of feldspars using cold Cathodo-Luminescence (CL) and Back-Scatter Electron (BSE) imaging; (b) acquisition of feldspar major and minor element abundances by Electron Probe Micro Analysis (EPMA) and Pb-Pb isotopes by Laser Ablation Multicollector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS). Feldspars throughout the components display a three-fold CL magmatic zonation associated with dissolution at the core followed by elemental spike zones of Ba, Sr (0.00 - 1.00 wt. %) and Ab [mol. %] with elemental re-equilibration back towards the rims. Such resorption surfaces correspond to rim-ward increase of 206Pb/204Pb and 208Pb/204Pb in alkali feldspars in host granitoid and andesine in early phase MME advocate dissolution attributed to punctuated mafic magmatic recharge from a mantle-derived component interacting with a crustal component. Bulk Pb-Pb isotope data also highlight the importance of magma mixing and mingling in the petrogenesis of the complex and define a simple binary mixing array reflecting quasi-contemporaneous hybridisation between such components. A temporal sequence of macro-scale and micro-scale events is proposed and it is evident that the process of mafic-felsic magma interaction seen at the outcrop-scale is encoded at the crystal-scale.	en
dc.description.status	Not peer reviewed	en
dc.description.version	Accepted Version
dc.format.mimetype	application/pdf	en
dc.identifier.citation	Zaniewski, A. 2018. Macro to micro-scale insights into granite petrogenesis; a case study from the Caledonian Ross of Mull granite (ROMG), Argyllshire, Northwest Scotland. PhD Thesis, University College Cork.	en
dc.identifier.endpage	286	en
dc.identifier.uri	https://hdl.handle.net/10468/6704
dc.language.iso	en	en
dc.publisher	University College Cork	en
dc.relation.project	European Commission (Marie Curie Fellowship)	en
dc.rights	© 2018, Adam Zaniewski.	en
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/	en
dc.subject	Caledonian	en
dc.subject	Granite petrogenesis	en
dc.subject	Ross of Mull granite	en
dc.thesis.opt-out	false
dc.title	Macro to micro-scale insights into granite petrogenesis; a case study from the Caledonian Ross of Mull granite (ROMG), Argyllshire, Northwest Scotland	en
dc.type	Doctoral thesis	en
dc.type.qualificationlevel	Doctoral	en
dc.type.qualificationname	PhD	en
ucc.workflow.supervisor	j.reavy@ucc.ie