Radiolarian abundances from IODP Holes 349-U1431D, 349-U1432C and 349-U1433A

Three of them, Sites U1431, U1432, and U1433, are located along a latitudinal gradient. We analyzed, using a light microscope, the total radiolarian abundance (radiolarians per gram of dry sediment) for middle and upper Pleistocene sedimentary sequences from these three sites.

Radiolarian abundances are higher uphole, in particular at Site U1432 (northern SCS). Site U1433 (southwestern SCS) contains the lowest numbers of radiolarians. In general, there are more barren samples in the older part of the section, with the upper Pleistocene having higher abundances and more consistent presence of radiolarians.