Now showing 1 - 4 of 4
  • Publication
    Clumped C-O isotope temperature constraints for carbonate precipitation associated with the Irish-type Lisheen and Navan Zn-Pb orebodies
    Mineral C-O isotope values are controlled by crystallization temperature and the isotopic composition of the fluid.
  • Publication
    Enhancing 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.
  • Publication
    Constraining fluid mixing processes at the Irish-type Lisheen and Navan Zn-Pb orebodies: preliminary evidence from clumped C-O isotopes
    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 .
  • Publication
    First Things First: Providing Metacognitive Scaffolding for Interpreting Problem Prompts
    When solving programming problems, novices are often not aware of where they are in the problem-solving process. For instance, students who misinterpret the problem prompt will most likely not form a valid conceptual model of the task and fail to make progress towards a working solution. Avoiding such errors, and recovering from them once they occur, requires metacognitive skills that enable students to reflect on their problem-solving processes. For these reasons, developing metacognitive awareness is crucially important for novice students. Previous research has shown that explicitly teaching key steps of programming problem-solving, and having students reflect on where they are in the problem-solving process, can help students complete future programming assignments. Such metacognitive awareness training can be done through personal tutoring, but can be difficult to implement without a high ratio of instructors to students. We explore a more scalable approach, making use of an automated assessment tool, and conduct a controlled experiment to see whether scaffolding the problem-solving process would increase metacognitive awareness and improve student performance. We collected all code submissions by students in both control and experimental groups, as well as data from direct observation using a think-aloud protocol. We found that students who received the intervention showed a higher degree of understanding of the problem prompt and were more likely to complete the programming task successfully.
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