Description: The carbonate islands of Bermuda sit on a volcanic rise of uncertain origin.  Although the basaltic flows appear to have originated at the mid-ocean ridge over 100Ma, there are younger intrusions of ultramafic lamprophyre with an unclear source.  Two lines of research are proposed for the upcoming year.

Description: There is a lack of understanding about the timing of phlogopite crystallization in ultramafic lamprophyres in general, and in the Bermuda Rise, specifically. Petrography and chemistry of the phlogopite will be used to determine whether these are primary or secondary in nature and what the chemistry of the fluids in the rocks. Study may include petrographic work, electron microprobe, and laser ICP-MS.

Description: It has been proposed by some that the carbonate veining in the volcanic rocks is magmatic in origin, related to the silica-undersaturated intrusive rocks.  Other propose that it they are recycled marine carbonates.  Paragenesis of the veins will be determined using detailed petrologic and geochemical study.  Research may include microscopy, electron microprobe, cathodoluminescence, laser ICP-MS, and carbonate isotopes.

Description: Cordierite is a mineral that can occur as an igneous phase in peraluminous granites, such as the South Mountain Batholith (SMB), but little is known of its role in controlling magma evolution. Owing to a relatively open structure, as well as octahedral sites occupied by Mg and Fe, it is possible that this mineral could be a significant host for other transition metals (Co. Ni), as well as large radius cations (rare-earth elements, U, Th, Pb), and therefore influence the behaviour of these elements over the course of SMB crystallization. In this study, cordierite-bearing samples obtained from the various intrusive phases of the SMB, as well as the similar Musquodoboit batholith, will be analysed for major and trace elements by electron microprobe and laser ablation ICPMS, respectively. This data will be used to constrain cordierite-melt partitioning, which will be combined with data for other minerals to
construct simple crystallization models to test against the observed behaviour of trace elements in the SMB. This thesis will support on-going work to better understand the differentiation history of the SMB and the potential to develop mineral deposits associated with extreme degrees of magma fractionation.

Description: Biotite and apatite are common phases in felsic igneous rocks, but there has been little work done to make full use of various trace element exchange reactions between these minerals to estimate such intensive parameters as crystallization temperature (T) and magma redox state (oxygen fugacity, fO2).
In addition to measurements of trace element partitioning, essential for the development of reliable T and fO2 indicators are constraints on the temperature at which the relevant element exchange effectively ceases, otherwise known as the closure temperature. This parameter will dictate if the conditions recorded are indeed “magmatic”, or correspond to cooling below the solidus. Estimates of closure temperature can be done by conducting laboratory experiments to measure diffusion coefficients as a function of temperature for the various elements of interest in biotite and apatite. Aside from the halogens (Cl, F), Pb, Sr and the rare-earth elements (apatite only), there are no data for diffusion of other elements of interest. In this study, samples of biotite and apatite will be made into
diffusion “couples”, then annealed at high temperature for various durations to generate compositional gradients that will be measured by electron microprobe or laser ablation ICP-MS, depending on the element. From these gradients, diffusion coefficients will be extracted by simple mathematical inversion of the relevant diffusion equations, and the variation in diffusion coefficient with temperature will be used to develop a general expression for the closure temperature. Results will be of fundamental importance to ongoing studies of trace element partitioning relevant to felsic magmas, and the development of thermometers and oxygen barometers specifically applicable to plutonic rocks.

Description: The lunar crust is dominated by anorthosite, which forms much of the lunar highlands, the bright and heavily cratered areas that you can see on the moon with the naked eye. This is at least 4.35 billion years old (Barboni et al. 2017) and is thought to have formed over a ~200 million year period. The anorthosites are thicker on the farside (~30-50 km) versus the nearside of the moon where they reach zero thickness in the Mare impact basins, the dark areas visible on the moon’s surface. The anorthosites are thought to have formed from a planetary-scale, magmatic fractionation process as suggested by the original lunar magmatic ocean (LMO) model (Smith et al. 1970; Wood et al. 1970). The LMO model suggests an early, 1000km deep, molten lunar surface developed and was enriched in plagioclase. Being less dense, the plagioclase floated to form the anorthosites of the lunar highlands. There are now several models supported by increasing volumes of data that suggest more complex formation mechanisms. The onion-skin model suggests a LMO with limited circulation under an initially thin, quenched crust. This produced rapid accumulation of anorthosites and minor, interstitial, mafic liquids. Tidal overturning of the plagioclase cumulates then prolonged the crystallization times (Elkins-Tanton et al. 2011). A second model, which attempts to also explain the asymmetric nature of the lunar crustal thicknesses, suggests that circulation may be the result of a giant impact which caused early differentiation of the nearside and farside lunar surfaces (Aria et al. 2008). A third model suggests that serial magmatism, and recycling of crystallizing plagioclase into a pre-existing quenched crust, produced the variety of assemblages found in many lunar samples (Gross et al. 2014). Another recent model suggests that modification of the initial crust formed from the LMO was aided by widespread early bombardment. This in turn created a series of magma seas that differentiated to result in the observed compositional variations in the lunar highlands (Vaughan et al. 2013). In this study, we will examine a small suite of lunar meteorite samples which has recently been obtained, including several pieces of NWA 11474 and NWA 12593. These meteorites are lunar breccias and contain clasts of anorthosite and mafic minerals. The first part of the project will involve a detailed documentation of the variations in mineral compositions in these samples. This will allow the range in lunar anorthosites represented to be determined. Preliminary crystallization temperatures will also be calculated using this data. Minor elements such as Sr, Ba and rare-earth elements including Eu will also be measured. Published distribution coefficients for trace-elements in plagioclase crystallizing from a LMO (Sun et al. 2017) will be used to determine whether these samples crystallized from a single-composition magma or represent more than one phase of crystallization from several magmas. Results will be compared with other studies to help refine the models of lunar crustal formation. Students interested in this project should contact Dr. Richard Cox (richard.cox@dal.ca).

Description: Kimberlites are exotic volcanic rocks, which are the main primary source of diamonds and the deepest magmas that reach the surface of the Earth. The origin of kimberlites is linked to processes in the subcontinental mantle and is still poorly understood. Complex composition of kimberlites precludes determination of crystallization conditions and composition of these magmas. This project will develop a new method for examining temperature and oxidation state (oxygen fugacity, fO2) in kimberlites using geometry of etch pits on diamonds. Natural diamonds recovered from kimberlites typically show triangular etch pits (trigons) formed during partial dissolution of diamond in kimberlite magma. Experiments show that size, orientation and shape of these trigons depend on temperature and oxygen fugacity. This project will experimentally calibrate thermometer and oxygen barometer based on the size and shape of positively-oriented trigons for near-surface conditions. It will be used to examine emplacement conditions of hypabyssal kimberlite forming pipes and dykes. The study will involve experiments at 0.1 MPa conducted in gas-mixing furnace, where temperature and fO2 can be varied. The surfaces of diamond crystals before and after experiments will be examined with an Atomic Force Microscope, which allows quantitative study of surfaces with resolution down to few nm. Experimental results will be compared to etch pits on natural diamonds from Snap Lake kimberlite pipe to shed more light on ambiguous emplacement history of this kimberlite body.

Description: Species are declining at an alarming rate across the globe and there is a need for spatial-temporal methods of analyses to contribute information to conservation management. Open data on biodiversity, protected areas, and landcover type among others are widely available to support research in this area.  Potential projects are possible and up to student interest and skill level and can include research on habitat change over time, examining wildlife-human interactions, modeling landscape connectivity, developing change models over time, and quantifying fragmentation and time to extinction. Students with skills in geospatial analysis, R coding, and/or remote sensing would be well-suited to this type of research.

Description: The Northwest Atlantic Ocean off Nova Scotia is undergoing some of the most rapid warming of any ocean region on Earth. To better predict how this warming will affect patterns of marine productivity in the future, we need better paleo-proxy data from the past. As a contribution toward this overall goal, an honours student is invited to validate a new organic geochemical approach (compound-specific isotope analysis of amino acids) on samples of marine algae collected periodically over a spring-to-winter cycle. Specifically, we will test whether the seasonal transition from large-cell, diatom-based production in spring, to small-cell, flagellate-based production in summer is reflected in carbon isotopic signatures of seawater filtrates. The student will carry out field work locally in Bedford Basin and the Northwest Arm (must be able to begin field work in April) and perform wet chemistry sample derivatization and mass spectrometric analysis in the Stable Isotope Biogeochemistry Laboratory. This research will support the ongoing work of two PhD students and several MSc students.  Contact: Dr. Owen Sherwood: owen.sherwood@dal.ca

Description: Nature exposure is proven to be crucial for children’s development by enhancing their physical and mental well-being, encouraging independence, creativity and problem-solving skills, and nurturing a deeper appreciation for nature. Further, one’s connection to nature is positively correlated with developing pro-environmental attitudes, knowledge and beliefs as an adult, and increasing the probability of conservation behaviours and attitudes later in life. This Honours thesis study will build on the work of Omidvar and Wright (2019) and MacKeen & Wright (2021) in which a bioaffinity (connectedness to nature) games testing tool was developed, tested and then modified to be more culturally, geographically and developmentally appropriate to the age of the participants and location in which the individual study takes place. The newly modified games testing tool will undergo reliability and validity testing in summer 2021 using psychometric assessment techniques. We are looking for an Honours thesis student who will support the research team in the testing of the tool with pre-school children during summer 2021 (approximately 20 hours in total – dates/times to be determined) and who will take the lead role in analyzing the bioaffinity results of the Halifax participant data, as well as running comparative analyses between the Halifax results and data previously collected using this bioaffinity test with children in a nature-based pre-school in Eleuthera Bahamas. Students interested in this project should contact Dr. Tarah Wright (tarah.wright@dal.ca). Note: It may be possible to combine this thesis with an Environmental Science Internship class (ENVS 3000) in Summer 2021, but this is not mandatory in order to be considered for this project as an Honours student.

Description: The Arts are uniquely placed to transform the conversation around climate change and translate it into action. Artists and the wider cultural community have a unique and critical role: they deal with the art of the possible and influence new ways of being, doing and thinking. Arts and culture not only respond to the world around us; they also influence our individual and collective experiences, and shape the direction we take. Yet Arts organizations can have an impact on the environment as well through their various activities. As such, this project will have the student partner with an Arts organization (i.e. Neptune Theatre, Dalhousie Fountain School of Performing Arts, Nova Scotia Art Gallery, etc.) to begin to examine the physical impact of the organization in order to better inform decision making in the future. The student will help the organization to measure their energy use, water consumption, waste generation and recycling, travel and production materials. It is anticipated that the results can help to inform the organization’s environmental strategy and organisational priorities.

Description: Seismometers record signals from more than just earthquakes. High frequency seismic noise is generally correlated well with human activities (e.g., traffic). To prevent the spread of the COVID‐19, a series of regulations have been issued in Halifax, expectedly leading to the change of human activities. Seismic noise analysis provides a new window to monitor the COVID-19 societal response in Halifax. In this project, continuous seismic data (station: HAL) before and after the COVID-19 will be analyzed. Seismic noise levels will be compared to the provincial regulations and the number of infections. Students interested in this project should contact Dr. Miao Zhang (miao.zhang@dal.ca).