The geochemical study of rocks S.W. of Clifden, Co. Galway, Connemara, Ireland

Singh, Dharm (1984) The geochemical study of rocks S.W. of Clifden, Co. Galway, Connemara, Ireland. MSc(R) thesis, University of Glasgow.

Abstract

An area of 10 sq.km. S.W. of Clifden, Co. Galway has been studied. The area consists of the Delaney Dome formation mace of siliceous granoclastites surrounded by the Ballyconneely amphibolites which grade outwards into the Errismore metagabbros. About 72 samples of siliceous granoclastites and 120 of Ballyconneely amphibolites have been analysed by X.R.F. methods for all major elements and 13 trace elements (Cr, Co, Ni, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Pb, Th). This data together with some microprobe abalyses are presented and used to deduce the origin of the siliceous granoclastites and the "way up" of the Ballyconneely amphibolites. The comagmatic nature of the amphibolites and the Errismore metagabbros is proved using major elements and supported by trace elements. The amphibolites young towards the centre of the Delaney Dome from the Errismore metagabbros and are struxturally inverted. The parent of the siliceous granoclastites is shown to be rhyolite or rhyodacite by using both major and trace element chemistry. This acid volcanic rock has been crushed and mylonitised. The chemical methods used enable the distinction of metaquartzo-feldspathic rocks of sedimentary origin (sandstones or arkoses) from those of plutonic origin (granites or gneisses) from those of volcanic origin (rhyolite-dacite). These methods can be applied to other areas of problematical metaquartzofeldspathic rocks. These results have contributed significantly to identifying the Connemara nappe.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Colleges/Schools: College of Science and Engineering
• Supervisor's Name: Leake, Prof. B.E.
• Date of Award: 1984
• Depositing User: Ms Anikó Szilágyi
• Unique ID: glathesis:1984-82358
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jul 2021 14:39
• Last Modified: 11 Apr 2022 09:32
• Thesis DOI: 10.5525/gla.thesis.82358
• URI: https://theses.gla.ac.uk/id/eprint/82358

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