Aminostratigraphy of sediments of the SW Bay or Bengal

Abstract

Amino acid enantiomeric (D/L) ratio is a stratigraphic tool of Recent sediments. The method which came into being 35 years ago1, is not a precise dating tool like, for example, the radiocarbon method, as the extent of racemization may not wholly depend on time. Several environmental factors like temperature, pH, bacteria, minerals and water content of the ambient medium affect the racemization rate2. Moreover, the quantification of the enantiomeric (D and L) components is a tedious process involving the preparation of GC/HPLC-separable derivatives of amino acids from the sediment hydrolysates. Yet, the global community of earth scientists, on the lookout for multiple palaeo proxies, has continued to pay attention to this method, as it offers some special advantages under specified conditions3–6, and is relatively inexpensive.