Sedimentary environment in Lake Biwa -Carbon isotopes of lake and river sediments-

Abstract

Lake sediment cores in Lake Biwa, collected from the northern and southern basins, respectively, were measured for carbon content, d¹³C, and d¹⁴C. Acid-alkali-insoluble fraction (residue) and acid-soluble fraction obtained by acid-alkali-acid treatment of the sediments were analyzed. The sediments in rivers flowing in Lake Biwa were also measured for C content and d¹³C of residue and acid-soluble fractions. The d¹³C and d¹⁴C values of residue were higher than those of acid-soluble fraction. We will report the difference, together with the result of different chemical behaviors of sediments in the northern and southern basins.