Anasazi cave dwellings built in volcanic tuff deposits, Bandelier National Monument, New Mexico. May 2004.
I have recently finished a NERC funded PhD studentship in the Grant Institute of Earth Science at the University of Edinburgh. My subject areas are Experimental Petrology and Mineral Synthesis specifically relating to granulite facies metamorphic terrains. Whilst mainly experimental, the project also included fieldwork in the Kerala Khondalite Belt, a Pan-African age granulite assemblage in southern India.
Poolanthara quarry, Kerala. A typical field locality from my recent study area in southern India. August 2005.
PhD Project Title:
Distribution of trace elements between zircon, garnet and melt: a key to understanding crustal processes (Start Date: February 2005)
In the field of U-Pb geochronology, zircon remains the most important mineral in crustal rocks. It forms through many processes, both igneous and metamorphic, and its structural and chemical resilience to high temperatures and open-system effects enhances its ability to retain a compositional and isotopic memory. As such, ages obtained from zircons in crystalline rocks are commonly used to constrain the timing of major geological events. However, a key to understanding orogenesis and crustal evolution is to be able to the relate age data from zircon to specific rock and mineral processes. Integral to this aim is to understand the behaviour of Zr during metamorphism, and the formation of zircon in relation to well-constrained metamorphic reactions and conditions. Understanding such processes improves our ability to place zircon-derived isotopic ages in a realistic metamorphic, and therefore orogenic context. Identifying the timing of prograde, peak and retrograde metamorphism in high-grade terrains can be problematic. Zircon is an accessory mineral often forming from the breakdown of Zr-bearing phases, which may occur in granulites at various stages on a pressure-temperature path. It is therefore of great importance to understand exactly when, where and how zircon is able to form and break down, and also ?survive? intense geological conditions. The aim of the research is to develop diagnostic criteria by which trace element signatures of zircons formed at high-temperature metamorphism and melting can be related to the processes that occur during the P-T-t evolution of the deep crust. The experimental data will be applied to interpret chemical signatures in zircon in garnet-bearing metamorphic rocks from the Kerala Khondalite Belt of southern India, and will provide an objective basis for interpretation of the timing of growth or recrystallisation of zircon, in this and many other high-grade terrains.
Metamorphism at high pressures and temperatures; geological evolution of S. India and Gondwana; mineral-melt trace element partitioning, synthetic materials analysis, experimental petrology.
2001- Northumberland, UK
2001- Assynt, NW Scotland, UK
2002- Isle of Skye, NW Scotland, UK
2002- Lake District, UK
2002- Independent Field Mapping, Connemara, W Ireland
2003- Troodos Ophiolite Complex, Cyprus
2004- MSci Field Seminar, Western USA- Inc. California, Nevada, Arizona, Utah & New Mexico
2005- Kerala Khondalite Belt, India
Enjoying the midday sunshine during fieldwork in Death Valley, California, one of the hottest places on the planet! May 2004.
"The Incomparable Valley" Yosemite National Park, California, with 'Half Dome' in the distance. April 2004
Ship Rock, New Mexico, is a 600m high volcanic neck consisting of minette breccia and lava. In the foreground is one of the many dikes that radiate from the central edifice. May 2004
If you're going to get your van stuck, then do it in some nice scenery! This view across the San Francisco Volcanic Field in Arizona is dominated by SP crater, a spectacular 800ft cinder cone. Its relatively young age, 71,000 yrs, is highlighted by its steep, straight sides and dark appearance compared to the older cones nearby. May 2004