Chemical Evolution of the Earth's Interior

EART34201 Chemical Evolution of the Earth's Interior 10 Semester 1 Undergraduate Level 6 Brendan McCormick Kilbride Unit coordinator 1 FHEQ level (Framework for Higher Education Qualifications) ' Last part of a Bachelors ' European Credit Transfer & Accumulation System Rating : 5.0 In addition to the first-order structure of core, mantle and crust, the solid Earth preserves chemical heterogeneity at a range of smaller length-scales reflecting the differentiation and cycling of elements over the entirety of geological time. A significant factor underpinning the development of this heterogeneity is the production of magma within the Earth. The compositions of primary melts, magma fractionation, transport and crystallisation have all played important roles in the chemical evolution of our planet, from the onset of subduction on Earth to present-day interactions of crustal reservoirs with the deep interior of our planet. The lectures in this unit will give an overview of established petrological, radiogenic and stable isotope and geochronological techniques that lead into a description of different length-scale terrestrial chemical and isotopic reservoirs. First-order planetary-scale processes controlling the formation and mutual interaction of these reservoirs (e.g., mantle plumes) will be discussed, with a detailed treatment of several relevant case studies. Practical classes will provide an opportunity for students to solve problems in the context of material and case studies covered in the lectures. These shall include (but are not limited to) integrating petrographic observation with geochemical data to establish petrogenesis, calculating rates of magmatic processes and timescales from trace element and isotopic data, and carrying out modelling of magmatic processes to quantify geochemical exchanges. In addition to the first-order structure of core, mantle and crust, the solid Earth preserves chemical heterogeneity at a range of smaller length-scales reflecting the differentiation and cycling of elements over the entirety of geological time. A significant factor underpinning the development of this heterogeneity is the production of magma within the Earth. The compositions of primary melts, magma fractionation, transport and crystallisation have all played important roles in the chemical evolution of our planet, from the onset of subduction on Earth to present-day interactions of crustal reservoirs with the deep interior of our planet. The lectures in this unit will give an overview of established petrological, radiogenic and stable isotope and geochronological techniques that lead into a description of different length-scale terrestrial chemical and isotopic reservoirs. First-order planetary-scale processes controlling the formation and mutual interaction of these reservoirs (e.g., mantle plumes) will be discussed, with a detailed treatment of several relevant case studies. Practical classes will provide an opportunity for students to solve problems in the context of material and case studies covered in the lectures. These shall include (but are not limited to) integrating petrographic observation with geochemical data to establish petrogenesis, calculating rates of magmatic processes and timescales from trace element and isotopic data, and carrying out modelling of magmatic processes to quantify geochemical exchanges. The aim of this course is to provide insight into the petrological and chemical controls on the evolution of the Earth’s mantle and crust, over approximately 4.5 billion years of geological time. The course will begin by covering advanced igneous petrological and geochemical theories and techniques, building on the foundation laid by petrology and geochemistry units in 2nd Year. Students will be equipped to learn and critically evaluate current concepts and controversies to do with Earth evolution, including the existence of mantle plumes and the timing of crust formation on the early Earth. <table border="1" cellpadding="1" cellspacing="1" style="width:500px;"> <tbody> <tr> <td colspan="2" rowspan="1">On the successful completion of the course, students will be able to:</td> <td>Developed</td> <td>Assessed</td> </tr> <tr> <td>ILO 1</td> <td>explain processes leading to the distribution of the elements on the early Earth, and the legacy these processes have for the present-day structure of our planet</td> <td>x</td> <td>x</td> </tr> <tr> <td>ILO 2 </td> <td>describe the mechanics of the processes that increase and decrease chemical heterogeneity in the mantle at length-scales <1 mm to 100s of km</td> <td>x</td> <td>x</td> </tr> <tr> <td>ILO 3</td> <td>analyse, manipulate and interpret petrographic, geochemical and isotopic data from natural samples to quantify processing of (and between) chemical reservoirs on the Earth</td> <td>x</td> <td>x</td> </tr> <tr> <td>ILO 4</td> <td>synthesise relevant petrological and geochemical data to explain (in detail) magmatism in specific areas, such as the Northeast Atlantic Igneous Province, through geologic time</td> <td>x</td> <td>x</td> </tr> <tr> <td>ILO 5</td> <td>integrate a variety of relevant literature data to critically evaluate important current controversial topics including (but not limited to) the timing of crust formation on Earth, the origin of Archaean greenstone belts, and the existence of mantle plumes</td> <td>x</td> <td>x</td> </tr> <tr> <td>ILO 6</td> <td>Comment on areas of uncertainty in our understanding of petrological processes as a consequence of technical limitations</td> <td>x</td> <td>x</td> </tr> </tbody></table>  Lecture and Practical 1. Major and trace element geochemistry in magmatic processes Lecture and Practical 2. Intensive parameters (thermodynamics in petrology) Lecture and Practical 3. Principals of isotope geochemistry and geochronology Lecture and Practical 4. The differentiation and crystallisation of magma Lecture and Practical 5. Early Earth building blocks and chemical reservoirs Lecture and Practical 6. Subduction on Earth 1: Magmatism in the Archaean Lecture and Practical 7. Timing of formation and petrogenesis of Earth’s continental crust Lecture and Practical 8. Subduction on Earth 2: Deep and shallow element chemical cycling Lecture and Practical 9. Present day mantle chemical and isotopic heterogeneity: The Mantle Zoo Lecture and Practical 10. Hot spot magmatism and Earth’s deep interior The course comprises 10 lectures, each with an associated practical class. Delivery of these will occur in a one lecture + one practical per week format, with the latter following the lecture. The timetabled slots in Week 5 will be given over to introducing the requirements for the continuous assessment (project) component of the unit. A final practical slot (in Week 11 or 12) will also be required to support the project work. The outstanding lecture slot of Week 12 will be used to explain the structure and format of the theory exam. The assessed project content/requirements will be designed (i.e., in relation to the new material being learned) such that they can be carried out continuously from mid-semester onward, to submission at the end of the semester.The lectures are posted as pdf files on Blackboard, and podcast recordings of lectures are uploaded automatically on the UoM lecture capture service. The lecture files are supplemented with extra information (files) in certain cases, such as details of the derivation of isotopic decay equations, to provide additional support for material touched on but not covered in detail in the lectures. Attendance at lectures provides an introductory platform from which students can further enhance their learning of the material by re-reading it in conjunction with the podcasts and notes they may have taken. Each lecture starts with a short (several minute) summary of the material from the lecture before, to embed content and establish the links and overlap between one lecture and the next.The practical material is delivered through a combination of hands-on sample examination (mainly by optical microscopy), paper- and computer-based exercises. The practical exercises are associated with eight of the lectures and are not assessed. There is lots of scope for formative feedback as the students are guided through the practicals. Staff and demonstrators will be on hand to help the students, and ensure that staff-student ratios remain acceptable. There is no obligation for students to finish the work within the 2 hours allotted time period, though the exercises are designed on average to take this long. Students will be encouraged to finish the work in their own time if they need to, and solutions to any problem-based exercises will be posted on Blackboard within a week. A feed-forward statement posted on Blackboard at the beginning of the semester will provide information on how to do well in the practical classes and the course more generally. 1 Written exam 70% 8 Practical skills assessment 30%  <table border="1" cellpadding="1" cellspacing="1" style="width:500px;"> <tbody> <tr> <td>Assessment type</td> <td>% Weighting within unit</td> <td>Hand out and hand in dates</td> <td>Length</td> <td>How, when and what feedback is provided</td> <td>ILO tested</td> </tr> <tr> <td>Practical ‘project-style’ exercise involving samples, raw data and literature sources that students will need to integrate to answer a series of short answer questions, culminating in them critically evaluating the validity/importance of some petrological process or model.</td> <td>50%</td> <td>Mid-semester to end-semester</td> <td>5-6 weeks</td> <td>Individual and group-level feedback will be emailed to students and/or posted on Blackboard within 15 working days of submission.</td> <td>3*, 4*, 6*</td> </tr> <tr> <td>Exam</td> <td>50%</td> <td>End-of-semester exam period</td> <td>2 hr</td> <td>No formal personalized feedback given. However, students may view their script after the exam period by arrangement and there will be general feedback in the unit review.</td> <td>1, 2, 4, 5,6</td> </tr> <tr> <td colspan="6">*ILOs 3 and 4 are primarily assessed in the project exercise. ILO 6 will be assessed in the project exercise, but depending on the theory exam question, may be assessed there too.</td> </tr> </tbody></table>  EART22201 Igneous Minerals and Processes Pre-Requisite Compulsory EART24202 Metamorphic Minerals and Processes Pre-Requisite Compulsory EART26201 Principles of Geochemistry Pre-Requisite Compulsory BSc (Hons) Earth and Plan Scie BSc (Hons) Earth (Geology) Third Year Optional BSc (Hons) Earth and Plan Scie BSc (Hons) Earth (Planet Sci) Third Year Optional BSc (Hons) Earth and Plan Scie BSc (Hons) Earth (Geochemistr) Third Year Optional BSc (Hons) Earth and Plan Scie BSc (Hons) Eart and Plan (GPG) Third Year Optional MEarthSci (Hons) Ea and Pl Sci MEarthSci (Hons) Earth (Geolo) Third Year Optional MEarthSci (Hons) Ea and Pl Sci MEarthSci (Hons) Earth (Plane) Third Year Optional MEarthSci (Hons) Ea and Pl Sci MEarthSci (Hons) Earth (Geoch) Third Year Optional MEarthSci (Hons) Ea and Pl Sci MEarthSci(Hons)Ea&Pl Sci(G&PG) Third Year Optional MEarthSci (Hons) Earth Industr MEarthSci EPS w IE (GeoChem) Third Year Optional MEarthSci (Hons) Earth Industr MEarth Sci (Hons) EPS IE (GPG) Third Year Optional MEarthSci (Hons) Earth Abroad MEarthSci EPS Abroad (PS) Third Year Optional MEarthSci (Hons) Earth Abroad MEarthSci EPS w YA (Geochem) Third Year Optional MEarthSci (Hons) Earth Abroad MEaSci (Hons) EPSwYA (GPG) Third Year Optional MEarthSci (Hons) EPS with Res MEaSc (H) EPS w R (GeoChem) Third Year Optional MEarthSci (Hons) EPS with Res MEaSc (H) EPS w Res (GPG) Third Year Optional MEarthSci (Hons) EPS with Res MEaSc (H) EPS (Plan Sci) w Res Third Year Optional Philpotts, A. & Ague, J. 2009. Principles of igneous and metamorphic petrology. 2nd Ed. Cambridge University Press.Condie, K.C. 2016. Earth as an evolving planetary system. 3rd Ed. Elsevier, Amsterdam. 574 pp.Articles from the scientific literature – a selection of compulsory and optional reading will accompany each lecture 0 0 100