The terrestrial mollusks as new indices of the Asian paleomonsoons in the Chinese loess plateau

This paper presents the results of a new malacological analysis of the last glacial cycle in the Luochuan loess sequence (China). A high-resolution study of the malacofauna, decomposed into ecological groups, allows the characterization of intervals of strong summer or winter paleomonsoons. The three occurrences of currently southeastern species in the sequence indicate that the climate conditions were warmer and wetter than today at about 88,000, 60,000, and 10,000 years BP. The main occurrence of xeric taxa between 75,000 and 65,000 years is interpreted as drier than today. This result is in good agreement with the variations of the summer and winter insolation at 30°N, as with other independent indices of the paleomonsoons yielded by pedogenic, sedimentologic and modeling studies.