Dear list members I have received an enquiry (see below), from a post-doc here at Plymouth, that members may be able to help me with. Please feel free to reply either directly to me or the post-doc, or via the list. Many thanks Steve Enquiry I am undertaking 14C dating of marine cores using specimens of the foraminifera Globigerinoides ruber. G. ruber specimens can be white or pink, and when using this species for stable isotope analysis (O and C) typically only one colour is picked to avoid differing fractionation between the different white and pink specimens. I am unsure however whether when undertaking 14C measurements if a separation of the pink and white specimens is necessary, both colours inhabiting (I believe) the same part of the water column. A search of the literature has yielded no definite answer and any information of any effect the colour of ruber may have (if any) on 14C dates would be great. Thank you Dr Jodie Fisher Post Doctoral Research Fellow School of Earth, Ocean and Environmental Sciences University of Plymouth Drake Circus Plymouth Devon PL4 8AA UK Tel: +44 (0)1752 238673 Fax: +44 (0)1752 233117 email: [log in to unmask] <mailto:[log in to unmask]> web page: http://www.plymouth.ac.uk/pages/dynamic.asp?page=staffdetails&id=jkfishe r Palaeontology and Palaeoenvironments Research Group website http://www.research.plymouth.ac.uk/paleopalenv/ <http://www.research.plymouth.ac.uk/paleopalenv/> ------------------------------------------------------------------------ ------------ Dr. Stephen Grimes Senior Lecturer in Stable Isotope Geochemistry & Climate Change School of Earth Ocean and Environmental Sciences University of Plymouth Drake Circus Plymouth Devon PL4 8AA Office: Room 118 Fitzroy Building Tel. +44 (0)1752 233109 Fax. +44 (0)1752 233117 e-mail. [log in to unmask] <mailto:[log in to unmask]> Web page. http://www.plymouth.ac.uk/pages/dynamic.asp?page=staffdetails&id=sgrimes <http://www.plymouth.ac.uk/pages/dynamic.asp?page=staffdetails&id=sgrime s>