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Dennis, Paul
Preferred name
Dennis, Paul
Official Name
Dennis, Paul
Research Output
Now showing 1 - 3 of 3
- PublicationConstraining fluid mixing processes at the Irish-type Lisheen and Navan Zn-Pb orebodies: preliminary evidence from clumped C-O isotopes(2016-09-04)
; ; ; ; Our research has applied the clumped O-C isotope technique to the Irish Zn-Pb ore field. Preliminary clumped C-O data will be presented from the Lisheen Zn-Pb orebody (22.3 Mt mined at 11.7% Zn and 2.0% Pb) [4] along with fluid inclusion data . Samples were analysed from all main carbonate generations across the deposit , including: regional dolomite (D 1), dark grey to black pre-ore hydrother mal dolomite (D 2 ; also known as black-matrix breccia), medium-to-coarse-grained ore-stage white ferroan dolomite (D 3 ; white-matrix breccia) , late veins of ferroan dolomite (D4) and white calcite (C4), post-ore crosscutting pink saddle dolomite (D 5), and post-ore white blocky calcite (C 6). We will discuss existing metallogenetic models for the Lisheen deposit and the potential for clumped C-O analysis to constrain fluid flow pathways and mixing processes, and as a tool for mineral exploration .220 - PublicationEnhancing current understanding of Irish Zn-Pb mineralization: a closer look at the Island Pod orebody, Lisheen deposit(Society for Geology Applied to Mineral Deposits, 2017-08-23)
; ; ; ; Irish-type deposits are a series of Zn-Pb orebodies, formed from the carbonate replacement of Lower Carboniferous limestone, triggered primarily by fluid mixing. Current understanding of the complex fluid flow and mixing dynamics associated with mineralization is limited. By applying clumped O-C isotope analysis to these deposits, these processes can be constrained. Preliminary paragenetic studies of the Island Pod orebody (0.4 Mt @ 20% Zn & 1.6% Pb) have yielded textural evidence for early fluid mixing of sulphide-rich fluids, in a quiescent, far-from equilibrium environment, resulting in the rapid precipitation of dendritic galena and intergrowths of dolomite and sphalerite. Initial clumped O-C analysis has revealed temperatures of 100-170°C for hanging-wall white matrix breccias that accompanied ore formation. This technique will be used to constrain temperature variations across the orebody, thus yielding information on how the fluid evolved as precipitation continued. A more detailed paragenetic study is underway and will form the foundation of future clumped O-C isotope and Zn-Cu-S isotope analysis.424 - PublicationClumped C-O isotope temperature constraints for carbonate precipitation associated with the Irish-type Lisheen and Navan Zn-Pb orebodies(Taylor & Francis, 2017-04-03)
; ; ; ; ; Mineral C-O isotope values are controlled by crystallization temperature and the isotopic composition of the fluid.350