Diamond-bearing rocks have traditionally been associated with kimberlites located above the deeper cratonic roots, as exemplified by occurrences in southern Africa. Recent research and exploration however, has challenged this model and has yielded diamonds within rocks associated with thin cratonic lithosphere and mobile belts. These host rocks are often not traditional kimberlites and have mineralogies inconsistent with the restricted depth interval of 120-200 km typically seen in cratonic diamond-bearing kimberlites. Studies of inclusions within diamonds suggest that in some cases, diamonds hosted within these exotic rocks were formed at extreme depths below 670 km.It is proposed through the study of archived material and new samples collected during field work to address questions of age, depth of origin, and emplacement of a variety of off-craton diamondiferous rocks. Detailed study will focus on samples from three off-craton settings. The petrology and geochemistry of an occurrence of Mesozoic diamondif erous kimberlite dykes and sills from Pyramidefjeld, S.W. Greenland will be addressed. The geochemistry of the kimberlites and associated xenoliths will be characterised and these rocks will be dated using mass spectrometry methods and U / Pb systematics. Study will be made of the geochemistry and petrography of Archaean diamondiferous lamprophyres from Wawa, Canada. Deep mantle diamonds archived from Juina, Brazil will be measured for He isotopic composition and sulphide inclusions will be dated by Re-Os m easurements.The proposal aims to satisfy the HRM objectives by providing the participant with training and new analytical skills, amongst others, in the field of geochronology and from a high international-standard institution. The participant will also re ceive exposure to international-class materials for study, thus contributing to his personal development and, ultimately to the advancement of the Union's diamond geological and exploration communities.
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