Amino acid racemization for several DSDP samples (Table 1)

• Main Authors: Katz, Barry J, Harrison, Christopher G A, Man, Eugene H
• Format: Dataset
• Language: English
• Published: PANGAEA 1983
• Subjects: 12-114; 23-227; 24-238; 27-262; 3-15; 3-16; 42-372; 42-376; 9-83A; AGE; Alloisoleucine/leucine ratio; Calculated; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Epimerization extent; Event label; Glomar Challenger; Indian Ocean//FRACTURE ZONE; Indian Ocean//TROUGH; Indian Ocean/Red Sea/TROUGH; Leg12; Leg23; Leg24; Leg27; Leg3; Leg42; Leg9; Mediterranean Sea/BASIN; North Atlantic/RIDGE; North Pacific; Sample code/label; South Atlantic/HILL; Indian; Pacific; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.757460; https://doi.org/10.1594/PANGAEA.757460

Kinetic parameters for the epimerization of isoleucine in multispecific foraminiferal asemblages were used to establish the effects of burial depth and the geothermal gradient on the extent of reaction. It was observed that with a little as thirty meters of burial in a normal thermal regime there were differences between the extent of epimerization measured and that which would have been predicted for thermal equilibrium with bottom water temperatures. As would be expected, these differences are greatest when the heat flow (the geothermal gradient) and/or the sedimentation rates are highest. These effects were observed in most of the DSDP samples studied, and have been used to estimate the average heat flux since the time of sample deposition. Occasional anomalous effects were observed which could not be related to past or present heat flux. These were determined to be due to such geologic occurrences as slumping and reworking or to recent sample contamination. Other problems emerged related to bottom water temperatures including changes over geologic time which are unknown and could not be deduced. Thus, the presence of epimerization anomalies in DSDP cores as noted above limits the effectiveness of amino acid geochronology in such cores, unless these anomalies can be recognized as ab initio.