Isoleucine epimerization in Quarternary planktic foraminifera of sediment core GIK12519-2, Sierra Leone Rise ...

• Main Author: Müller, Peter J
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1984
• Subjects: Gravity corer Kiel type; M51; Meteor 1964; Institute for Geosciences, Christian Albrechts University, Kiel GIK/IfG; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.548489; https://doi.pangaea.de/10.1594/PANGAEA.548489

Panktonic foraminiferal tests of the spinose species Orbulina universa, of the non-spinose Globorotalia tumida-menardii complex, and of a mixed species assemblage (grain size fraction 200-400 µm) were isolated from Sierra Leone Rise core GIK13519-2 and analyzed for free, total, and bound (by difference) amino acids to study the isoleucine epimerization mechanism in fossil foraminiferal tests and to define empirical calibration curves for dating deep-sea sediments over the past 900,000 years.Total isoleucine epimerization curves typically separate into three "linear" segments of decreasing apparents rates with increasing time and exhibit a pronounced „species effect“. The degree of epimerization attained at time is considerably lower in O. universa than in G. tumida-menardii while the mixed species results scatter between the limits delineated by the two monospecific curves. Total allo/iso ratios are closely related to the proportion of free to total isoleucine accumulating in the tests indicating that the ... : Supplement to: Müller, Peter J (1984): Isoleucine epimerization in Quaternary planktonic foraminifera: Effects of diagenetic hydrolysis and leaching, and Atlantic-Pacific intercore correlations. Meteor Forschungsergebnisse, Deutsche Forschungsgemeinschaft, Reihe C Geologie und Geophysik, Gebrüder Bornträger, Berlin, Stuttgart, C38, 25-48 ...