INVESTIGATION OF LATE-QUATERNARY SEDIMENTS FROM THE SOUTH YELLOW SEA AND THE YANGTZE RIVER DELTA Maurizio Bonardi*, Luigi Tosi*, Jeanne Percival**, Chen Lirong*** and Andrea Zanucco**** * Consiglio Nazionale delle Ricerche, Istituto per 10 Studio della Dinamica delle Grandi Masse, San Polo 1364, 30125 Venezia (Italy). ** Geological Survey of Canada, 601 Booth St., Ottawa, Ont., K1A OE1 Canada. *** Institute of Oceanology, Academia Sinica, 7 Nan-Hai Road, Qingdao, 266071 China. * .. * Universita' di Padova, Dipartimento di Mineralogia e Petrologia, C.so Garibaldi 37,35137 Padova (Italy) Abstract The results of a study to determine the geochemical, mineralogical, magnetic and textural characteristics done on Late-Quaternary sediments from drill cores from the South Yellow Sea (core H106) and the Yangtze River Delta (core LA) (China) are reported. The Late-Pleistocene continental sedimentation is represented by clayey silt and hard clay layers, while the marine Holocene sediments consist mainly of clay (H106) and sand and clay layers (LA). Introduction Reported here are the results of a mineralogical, geochemical, paleomagnetic and textural investigation carried out with the purpose of characterizing Late-Quaternary sediments from two different depositional environments: the South Yellow Sea and the Yangtze River Delta. The imprinting of the climatic conditions that characterised the Last WOrmian phase are recognitiable in the overconsolidated clay layer that marks the Pleistocene/Holocene boundary. Particle size distribution was determined using a Brinkmann Particle Size Analyzer (Model 2010). The mineralogy of bulk materials and their clay-size separates were determined by X-ray powder diffraction analysis (XRD). South Yellow Sea, Core H106 Fifty-five clay and clayey silt samples representative of the last 20.000 years of sedimentation, were taken from a 600 cm-Iong core (H106), in 70 m of water (Figg. 1 J 2). 18 Bonardi, M., Tosi, L., Percival, J., Lirong, C., Zanucco, A. 1995. Investigation of Late Quaternary sediments from the South Yellow Sea and the Yangtze River Delta. In: (Marabini, F. Editor) Italian Contribution to the China-Italy Bilateral Seminar on Marine Geology, 4-6 October 1994, Qingdao, China. Istituto di Geologia Marina, CNR, Bologna, Tech. Rep. 40, 18-24.