Thirty-six sediment samples of approx. 10 cm^3 were taken.  The number of samples and the distance between consecutive samples vary among the sedimentary units described above due to their textural differences. Unit A (215-135 cm) were sampled every ~10 cm. Unit B (135-89 cm)  were sampled continuously every 2 cm. Unit C (89-10 cm) levels with abundant fine-grained matrix were selected. Unit D (the uppermost 10 cm) only one sample was taken. For each sample, 10 g of sediment was treated with hydrogen peroxide (H2O2{~}) 10% to remove organic matter, washed through 75 μm sieve, and dried at 40º C in a thermostatic oven. All foraminifera and ostracods from at least 2 g of dry sediment were picked and extrapolated to the whole pretreated sample to standardized abundance.