Chondrite meteorites contain the earliest solid material that formed within our Solar System, 4.6 billion years ago. These meteorites are predominantly made up of millimetre-sized particles known as chondrules, and very fine-grained (sub-micrometre) matrix . Refractory inclusions, millimetres to centimetres in size, are a third important component: objects named refractory inclusions include Calcium-Aluminium-rich Inclusions, or CAIs . Although we know that chondrules and some CAIs underwent melting and cooling on timescales of a few hours, within the first 2 million years of formation of the Solar System, we do not know what process was responsible for that heating . Models range from impact events to bow shock waves in the dusty protoplanetary disk. We can put constraints on the heating mechanism, as well as the dynamic evolution of different reservoirs of material within the disk, by studying the chemical and isotopic properties of these melted objects . This project will investigate the heating mechanism responsible for formation of refractory inclusions and chondrules, by combining petrologic studies of chondrite samples with laboratory experiments on refractory inclusion and chondrule analogues [e.g. 4]. Studies of the natural samples will serve as a basis for understanding the range of mineralogy and textures present in chondrites. Experiments will have two goals: firstly, to determine formation conditions for textures and mineral compositions seen in natural CAIs and chondrules, and secondly, to investigate the effects of melting and crystallization on the distribution of oxygen isotopes within these objects. Oxygen isotopes are an important tool to investigate early Solar System materials because there is a wide range of oxygen isotope compositions among CAIs and chondrules , as well as among chondrite groups . Analytical techniques to be used in this project include scanning electron microscopy (SEM) for investigating mineralogy and textures of natural and experimental samples, electron microprobe (EPMA) for measuring the chemical compositions of minerals, and secondary ion mass spectrometry (SIMS) for measuring oxygen isotope ratios in individual grains. Experiments will be conducted in a one-atmosphere gas-mixing furnace. Suggested skills needed – We are looking for an able and enthusiastic student with a strong background (MSc, MSci or BSc) in geoscience or physical sciences. No experience of working with planetary samples is necessary, but the candidate should have appropriate experience in igneous petrology and optical microscopy. Some knowledge of scanning electron microscopy, electron microprobe techniques and/or experimental petrology would be helpful but this is not essential.