Carbonation of the Oman Ophiolite during subduction and emplacement
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Zeko, David
issued: 2021-01-27T14:44:10Z
issued: 2021
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Fully carbonated peridotite, known as listvenite, is well exposed along the basal thrust of the Oman ophiolite. Outcrops of listvenite are a fossilized record of fluid-rock interactions that resulted in the storage of billions of tonnes of CO₂, providing researchers insight into an important global carbon sink and a potential natural analogue to in situ carbon sequestration. The goal of this thesis is to investigate the formation of listvenite using samples from the Oman Drilling Project to 1) characterize the petrology and geochemistry of listvenite, 2) determine the mineral reaction sequence and the physical and chemical conditions required and 3) constrain the potential sources of CO₂ bearing fluids. Three carbonated lithologies were observed: 1) serpentine with variable amounts magnesite and dolomite veining (ophicarbonate); 2) serpentine with abundant vein and matrix hosted magnesite, dolomite, talc and quartz (talc-ophicarbonate); and 3) intergrown magnesite, dolomite and quartz (listvenite). With the exception of H₂O, CO₂ and variable amounts of Ca, the major element geochemical composition of all three lithologies approximates unaltered peridotite. Fluid mobile trace elements such as Cs, Rb and Sr are enriched in listvenite to over 100-times that of unaltered peridotite and correlate with increasing δ¹³C values. δ¹³C values increase with carbonation from ~-7 δ¹³C in ophicarbonate samples through to ~+2 δ¹³C in listvenite, representing the progressive dilution of mantle-derived carbon with marine-derived carbon. Detailed petrography and thermodynamic phase equilibria modelling demonstrate that listvenite formed via a series of mineral reactions resulting in the breakdown of serpentine and the formation of magnesite, dolomite, talc and quartz. Crosscutting relationships between carbonate minerals and deformation structures, in combination with oxygen isotopic exchange thermometry, reveal that carbonation reactions were driven by at least two pulses of CO₂-bear…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/77182
note: CARBONATION OF THE OMAN OPHIOLITE DURING SUBDUCTION AND EMPLACEMENT by David Zeko BEnvSci (Hons), The University of Wollongong, 2009 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Geological Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) January 2021 © David Zeko, 2021 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis entitled: Carbonation of the Oman Ophiolite During Subduction and Emplacement submitted by David Zeko in partial fulfillment of the requirements for the degree of Master of Science in Geological Sciences Examining Committee: Prof. Greg Dipple, Earth, Ocean and Atmospheric Sciences, UBC Supervisor Prof. Lee Groat, Earth, Ocean and Atmospheric Sciences, UBC Supervisory Committee Member Prof. Brendan Dyck, Earth, Ocean and Atmospheric Sciences, UBC Additional Examiner Additional Supervisory Committee Members: Dr. Tyler Ambrose, Yukon Geological Survey Supervisory Committee Member iii Abstract Fully carbonated peridotite, known as listvenite, is well exposed along the basal thrust of the Oman ophiolite. Outcrops of listvenite are a fossilized record of fluid-rock interactions that resulted in the storage of billions of tonnes of CO2, providing researchers insight into an important global carbon sink and a potential natural analogue to in situ carbon sequestration. The goal of this thesis is to investigate the formation of listvenite using samples from the Oman Drilling Project to 1) characterize the petrology and geochemistry of listvenite, 2) determine the mineral reaction sequence and the physical and chemical conditions required, and 3) constrain the potential sources of CO2-bearing fluids. Three carbonated lithologies were observed: 1) serpentine with variable amounts magnesite and dolomite veining (ophicarbonate); 2) serpentine with abundant …
has type: Thesis/Dissertation
date issued: 2021-05
is shown at: 10.14288/1.0395750
language: eng
degree discipline: Geological Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-ShareAlike 4.0 International
rights URI: http://creativecommons.org/licenses/by-sa/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/77182