Brian O’Driscoll - Chromitite petrogenesis and PGE enrichment in the Rum layered intrusion, Scotland.
12:00pm - 1:00pm /
Friday 12th May 2017
/ Venue: Jane Herdman Lecture Theatre Jane Herdman Building
Type: Seminar /
Category: Department
- 0151 795 0619
- Jamie Hughes
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The 60 Ma Rum Layered Suite is a classic example of an open-system layered mafic intrusion. At certain stratigraphic intervals, platinum-group element enriched chromitite seams demarcate levels of new magma replenishment. In this seminar, I will discuss how field observations, petrology and geochemical data do not support the formation of these seams by crystal settling following mixing of the resident and replenishing magma; long considered to be important processes in the formation of such ore bodies generally. Instead, the evidence points to in situ crystallization, following localised assimilation of plagioclase-rich cumulate by the incoming magma. However, throughout the Rum intrusion, chromitite seams and their footwall rocks exhibit a breadth of structural and petrological complexity that continues to defy straightforward explanation, and I will also outline some recent work and future research directions in this respect