Timing and conditions of peak metamorphism and cooling across the Zimithang Thrust, Arunachal Pradesh, India

The Zimithang Thrust juxtaposes two lithotectonic units of the Greater Himalayan Sequence in Arunachal Pradesh, NE India. Monazite U–Pb, muscovite 40Ar/39Ar and thermobarometric data from rocks in the hanging and footwall constrain the timing and conditions of their juxtaposition across the structure, and their subsequent cooling. Monazite grains in biotite–sillimanite gneiss in the hanging wall yield LA-ICP-MS U–Pb ages of 16 ± 0.2 to 12.7 ± 0.4 Ma. A schistose gneiss within the high strain zone yields overlapping-to-younger monazite ages of 14.9 ± 0.3 to 11.5 ± 0.3 Ma. Garnet–staurolite–mica schists in the immediate footwall yield older monazite ages of 27.3 ± 0.6 to 17.1 ± 0.2 Ma. Temperature estimates from Ti-in-biotite and garnet–biotite thermometry suggest similar peak temperatures were achieved in the hanging and footwalls (~ 525–650 °C). Elevated temperatures of ~ 700 °C appear to have been reached in the high strain zone itself and in the footwall further from the thrust. Single grain fusion 40Ar/39Ar muscovite data from samples either side of the thrust yield ages of ~ 7 Ma, suggesting that movement along the thrust juxtaposed the two units by the time the closure temperature of Ar diffusion in muscovite had been reached. These data confirm previous suggestions that major orogen-parallel out-of-sequence structures disrupt the Greater Himalayan Sequence at different times during Himalayan evolution, and highlight an eastwards-younging trend in 40Ar/39Ar muscovite cooling ages at equivalent structural levels along Himalayan strike

Power, pedagogy and participation: ethics and pragmatics in research with young people

This paper addresses issues of methodology when attempting to investigate the opinions of young people. It uses the concept of ‘ethical reflexivity’ (Gewirz & Cribb, 2006) to theorise some very practical considerations of research in classrooms. Drawing specifically on three studies of young people’s understandings of citizenship and their views on topical issues, two from England and one from Lebanon, we present ways in which the ethical challenges of such research can be met. Whilst acknowledging the power relationship between researchers and informants, we suggest that what we call ‘pedagogical research approaches’ built on a participative methodology can open up a space where both parties benefit. We argue that, when working in schools, we can take advantage of our status as teacher educators to present ourselves simultaneously as insiders and outsiders. We have devised what are intended to be non-exploitative research instruments that permit the gathering of useful qualitative data during a short encounter. We illustrate our approach with examples of classroom activities we have developed to provide simultaneously a valid learning experience and usable data